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Gene co-expression analysis to characterize genes related to marbling trait in Hanwoo (Korean) cattle.

INTRODUCTION

The meat quality of cattle is determined by intramuscular fat deposition (marbling) (Lee et al., 2007) and could be improved by functional genomic studies of genetic factors. Beef is graded according to the amount of marbling since marbling makes beef more tender, flavorful, and juicy. It is one of the main factors used to determine beef quality grade in the United States (USDA, 1989), Japan (JMGA, 1988), and Korea. Several countries identify meat quality challenges, such as marbling, meat tenderness, carcass weight, muscling, and fat cover. All of these areas must be considered to provide consumers with high-quality products. In particular, marbling refers to the appearance of white flecks or streaks of adipose tissue between the bundles of muscle fibres in bovine skeletal muscle (Harper et al., 2001). It is driven through the development of adiposes in combination with declinging muscle growth (Hocquette et al., 2010). From one point of view, marbling might be an interaction among fat development, connective tissue or blood vessels. Kokta et al. (2004) reported the inreaction between myogenic cells and adipocytes to determine the rate and extent of myogenesis and adipogenesis during animal growth. Three genes were identified as being significantly correlated with bovine skeletal muscle based on microarray data from a gene network (Reverter et al., 2006). Jiang et al. (2009) reported that the genetic network was associated with 19 economically important beef traits. Recently, candidate genes for the marbling trait and their relationships were identified from the protein-protein interaction networks (Lim et al., 2011). Kim et al. (2011) identified the relationship between the expression of heat shock protein P1 (HSPB1) and its regulator genes from the gene network analysis in intramuscular fat of Hanwoo (Kim et al., 2011). These results reflect the fact that many biological pathways or interactions occur between muscle and fat within the skeletal muscle. Therefore, the study of marbling differences needs to analyze the complex interactions between biological pathways or genes from the network level.

Gene expression data have been used to successfully identify relationships between genes involved in biological mechanisms and to predict targetable genetic components associated with complex traits or disease states. Several studies have also shown that mRNA levels of candidate genes are heritable, affecting genetic analysis (Brem et al., 2002; Wayne and McIntyre, 2002; Schadt et al., 2003). Many complex traits in animals, such as disease susceptibility, development, and agricultural product quality, are controlled by interactions among several genes combined with environmental influences. Furthermore, patterns of covariation in the expression of multiple loci can be used to build networks that show relationships between genes and functional traits. These networks provide information on the genetic control of complex traits and can help identify causal genes that affect gene function, rather than gene expression (Haley et al., 2006). System-oriented approaches using gene expression data have been applied by animal geneticists to investigate livestock traits (Nobis et al., 2003; Donaldson et al., 2005; Smith et al., 2007), resulting in the identification and characterization of economically important causal trans-acting genes within QTL regions. These trans-acting regions share a common biological function (e.g., similar gene ontology function, metabolic pathway, transcriptional co-regulation) (Schadt et al., 2003; Gibson and Weir, 2005; Subramanian et al., 2005).

A weighted gene co-expression network is a gene correlation network created from expression profiling, with each gene having several neighbors (Peter and Steve, 2008). Gene co-expression network (GCN) is useful for identifying genes that control quantitative phenotypes and has been used as a "primary screen", to identify novel genes related to traits from thousands of possible genes. Gene expression networks serve as an effective approach for finding hub genes that have key regulatory roles. Fuller et al. (2007) demonstrated that two types of gene co-expression network analysis can find a body-weight-related gene from weighted gene co-expression network analysis (WGCNA). WGCNA analysis is applied in several research fields such as diseases (Ghazalpour et al., 2006; Miller et al., 2008), complex traits (Ghazalpour et al., 2006) and specific tissues (Oldham et al., 2006; Dewey et al., 2011).

In this study, we reported the gene co-expression network analysis of marbling trait-related genes in m. longissimus with divergent marbling phenotypes, and suggest evidences for the biological significance of highly connected genes in Hanwoo (Korean cattle).

MATERIALS AND METHODS

Microarray data processing

We used microarray experiments from intramuscular muscle samples of Korean Cattle (Hanwoo) in our previous study, related to the beef marbling study (Lee et al., 2010). Briefly, ten steers each from a low-marbled group (7.4 [+ or -] 2.4%) and a high-marbled group (23.7 [+ or -] 5.6%) were used in this study (Table 1). All arrays were processed to determine the robust multiarray average (RMA) (Irizarry et al., 2003) using the "affy" software package (Gautier et al., 2004). Expression values were computed in detail from raw CEL files by applying the RMA model of probe-specific correction for perfect-match probes. These corrected probe values were then subjected to quantile normalization, and a median polish was applied to compute one expression measure from all probe values. Resulting RMA expression values were log2-transformed.

Weighted gene co-expression network analysis

We selected the 4,000 most varying probes for the generation of a weighted gene co-expression network. We calculated correlations between the gene expression profiles of each pair of genes using Pearson's correlation coefficients (denoted as r). Then, the correlation measures were transformed into a connection strength using power adjacency function. The power adjacency function c = |cor[([x.sub.i], [x.sub.j]).sup.[beta]] was used to construct a weighted network as the connection strength between two genes. The weighted network represented "soft" thresholding that weighed each connection as a continuous number [0, 1]. We selected a soft threshold beta ([beta]) = 18 according to scale free topology criterion. A major advantage of weighted networks is that highly robust results are obtained with regard to the choice of the parameter beta ([beta]). A major aim of co-expression network analysis is to determine subsets of nodes (modules) that are tightly connected to each other. To organize genes into modules, we used a module identification method based on a topological overlap dissimilarity measure (Ravasz et al., 2002) in conjunction with a clustering method, which detected biologically meaningful modules. The topological overlap of two nodes refers to their relative interconnectedness. The topological overlap matrix (TOM) [OMEGA] = [[[omega].sub.ij]] provides a similarity measure, which has proven useful in biological networks (Ye and Godzik, 2004), where [l.sub.ij] = [[summation].sub.u] [a.sub.iu] a and [k.sub.i] = [[summation].sub.u] a is the node connectivity as follows:

[[omega].sub.ij] = [l.sub.ij] + [a.sub.ij]/min([k.sub.i], [k.sub.j]) + 1 - [a.sub.ij]

In the case of our network, equals the number of nodes to which both i and j are connected. To identify modules, we used TOM-based dissimilarity [d.sup.w.sub.ij]([d.sup.w.sub.ij] = 1 - [[omega].sub.ij]) in a hierarchical cluster analysis. Each module represents a group of genes with similar expression profiles across the samples and the expression profile pattern is distinct from those of other modules.

Connectivity and module membership

A weighted gene co-expression network identified gene modules for biological significance. Because gene modules may correspond to biological pathways, focusing the analysis on modules (and their highly connected intramodular hub genes) amounts to a biologically meaningful data reduction scheme. Highly correlated module genes are represented and summarized by their first principal component (which is referred to as the module eigengene (ME)). The ME isused to define measures of module membership (MM) which quantify how close a gene is to a given module. MM measures allow one to annotate all genes on the array and to screen for disease related intramodular hub genes. We used the intramodular connectivity [K.sup.q](i) that is biologically more meaningful than the whole network connectivity (Saris et al., 2009). It is calculated from the sum of connection strengths between a particular gene and all other genes in the module [K.sup.q](i) = [[summation].sub.j[member of]q] [[absolute value of Cor([x.sup.i], [x.sup.j])].sup.[beta]], where q denotes a specific module. We also used the MMq(i,) which is the correlation of the ME and the gene expression profile. As explained in detail in (Horvath and Dong, 2008), the MM of gene i in module q can be defined [MM.sup.q](i) = Cor([x.sub.i], [ME.sup.q]), where larger absolute values mean greater similarity between a gene [x.sub.i] and the q-th module eigengene. The statistical significance of MM (denoted as p MM red) is carried out from the correlation test p-value of the WGCNA package. Finally, we can identify genes that have a high significance for marbling score as well as high MM in interesting modules using the gene significance (GS) and MM measures (Peter and Steve, 2008). We first defined a measure of GS that is obtained from the correlation between the gene and the trait. The higher the i-th gene's [absolute value of GS(i)], the greater its biological significance. For the i-th genes, we identified GS for marbling score (denoted as GS marbling score) as the absolute value of the Student t-test statistic for testing differential expression between high- and low-marbled groups. We defined a measure of module significance (denoted as p.MM.red) as the eigengene significance that is the correlation between the ME and the expression profiles.

Functional enrichment analysis

We performed functional enrichment analysis in given modules that were associated with marbling score enrichment in the Gene Ontology or KEGG pathway terms, using the Database for Annotation Visualization and Integrated Discovery (DAVID) tool (http://david.abcc. ncifcrf.gov/). It computes a fisher's exact test p-value. Functional relationships of our genes of interest were used in the Pathway studio program (Stratagene, La Jolla, CA, USA) (Nikitin et al., 2003). We investigated the common regulators and targets of the significant genes in the modules.

RESULTS AND DISCUSSION

Weighted gene co-expression network analysis

We used WGCNA in a first attempt to identify marbling score associated coexpression modules and their key functions. A weighted gene co-expression network was constructed using expression data from the high- and low marbled groups, utilizing the 4,000 most varying transcripts from the 24,128 transcripts present on the array. To find modules of highly correlated genes, we used average linkage hierarchical clustering, which uses the TOM as dissimilarity. We were able to identify 17 distinct modules (except for the "grey" module, which is not grouped into any module) for groups of genes with high topological overlap. Figure 1 shows the co-expression modules ranging in size from 41 (lightcyan) to 1,024 (turquoise) genes. The mean overall connectivity is 24.6, and ranged from 8.83 (midnightblue) to 34.44 (turquoise). Detailed information about all genes and their network properties are calculated (data not shown).

Detection of co-expression modules related to marbling score

The coexpression modules correspond to branches and are color-coded (black, blue, brown, cyan, green, greenyellow, lightcyan, magenta, midnightblue, pink, purple, red, salmon, tan, turquoise, and yellow module). We identify modules that are significantly associated with the measured phenotypic traits. We found that the module significance measures in the three modules (red, tan and lightcyan) were significantly correlated (Supplementary data 1). The red module (referred as MEred) was the most significant (correlation with marbling score r = 0.77, correlation p = 0.008) for marbling score. It also showed significant results for intramuscular fat (r = 0.72, p = 0.02) and water capacity (r = 0.79, p = 0.006). Figure 2(A) shows red module significance against all traits. The tan module (referred to as MEtan) is significantly associated with three phenotypic traits: marbling score (r = 0.68, p = 0.03), intramuscular fat (r = 0.74, p = 0.01) and meat color CIE L (r = 0.62, p = 0.05). The red and tan modules were related to marbling score, intramuscular fat. Generally, intramuscular fat is often called an indicator of marbling, because they are highly correlated. The genetic and phenotypic correlations between them were 0.69 to 0.74 and 0.7, respectively (Park et al., 1994; Crews et al., 2003). The lightcyan module is related only to marbling score (r = 0.66, p = 0.04). We also investigated the relationship of the MEs to other phenotypic variables. Table 2 shows the modules that have significant p-values against the types of phenotypes.

As detailed in the Methods section, we calculated a measure of MM that can define each module. Large absolute values of MEred(i), MEtan(i) or MElightcyan(i) indicate the gene is closed to the red, tan or lightcyan module. In contrast, if MMred(i) is closed to 0, then ith gene is uncorrelated with the red module eigengene and is unlikely to be part of the red module. We also quantify the association of individual genes with the marbling score trait in each module by determining GS as the absolute value of the correlation between the gene and the trait. Figure 2(B) shows a relationship between the GS and MM in the red module (r = 0.43, p = 1e-11). However, there is no significant result (r = 0.079, p = 0.44) between GS and MM in the tan module. This implies that hub genes of the red module also tend to be highly correlated with marbling score. We reported 84, 17 and 2 probes that have significant results (p [less than or equal to] 0.05) with the GS and the MM against the marbling score in the red, tan and lightcyan module, respectively. Network properties of the top-ranking genes are shown in Table 3. For example, glomulin, FKBP associated protein (GLMN), showed the most significant result for marbling score (r = 0.95, p.GS.marbling score = 3.69e-5) in the red module. This is involved in differentiation of vascular smooth muscle cells (VSMC) (McIntyre et al., 2004) and indicated as a marker of VSMC. According to Davies et al. (2005), the generation of lipid-filled VSMC resulted from either adipocyte differentiation or direct promotion of lipogenesis as the result of LXR/SREBP1c activation in humans (Davies et al., 2005). Neuregulin 1 (NRG1), integrin-binding sialoprotein (IBSP) and solute carrier family 46, member 1 (SLC46A1) have the largest module membership (MM = 0.93) in the red module. These genes also show significant p-values for gene significance against the marbling score phenotype.

Pathway and GO analysis for the red module

We performed functional enrichment analysis for the red module according to the GS and MM measurement. GO and biological pathway analysis were used to search for the biological significance or functional relationship of the significant genes associated with marbling score. We explored the functional relationship (expression, regulation and direct interaction) in the red module using the pathway studio program. Out of 15 pathway annotated genes, 8 muscle-related genes (NRG1, RB1, JUN, CHRNE, CXCL10, IL6, SRF and FGFR2) have a direct relationship in the pathway analysis (Figure 3). These genes have significant p-value (p < 0.05) for MM or GS in red module for marbling score. The NRG family have been observed to stimulate myotube formation and muscle specific gene expression (Florini et al., 1996; Lebrasseur et al., 2003) and facilitate glucose uptake that is an important factor for improving marbling in adipocyte of beef cattle (Suarez et al., 2001). Activation of NRG/ErbB signaling may also mediate one or more adaptive growth and metabolic responses of skeletal muscle to exercise. Fibroblast growth factor receptor 2 (FGFR2) is a member of four transmembrane tyrosine kinase receptors and affects skeletal muscle myogenesis (Rhoads et al., 2009). The function of satellite cells during muscle regeneration is regulated by many growth factors and cytokines such as fibroblast growth factor (FGF) and transforming growth factor-[beta] (TGF-[beta]) families, insulin-like growth factors-1 and -2 (IGF-1, IGF-2), hepatocyte growth factor (HGF), and interleukin-6 (IL-6) (Grefte et al., 2007). One of the FGF family, polymorphisms in the FGF8 is associated with carcass quality, growth and feed efficiency in beef cattle (Moore and Marques, 2008). Interleukine 6 (IL6) regulates skeletal muscle differentiation and metabolism. In particular, it increased glucose incorporation into glycogen, glucose uptake, lactate production, and fatty acid uptake and oxidation in humans (Al-Khalili et al., 2006). Retinoblastoma 1 (RB) plays an important role in determining whether myoblasts proliferate or differentiate (Rosenthal and Cheng, 1995). RB family proteins promote adipogenesis by direct interaction with C/EBPs (Chen et al., 1996). Chemokine ligand 10 (CXCL10) is differentially expressed in the longissimus tissues from Meishan, Meishan x Large White cross and Large White pigs (Li et al., 2010). Serum response factor (SRF) was shown to be differentially expressed between fat and lean and between different muscles using RT-PCR in chickens and was suggested as a potential regulator of several functional candidates affecting glycogen turnover in the muscle for meat quality (Sibut et al., 2011). Jun oncogene (JUN) is called an activator protein 1 (AP-1) and is known to inhibit myogenic differentiation (Su et al., 1991). It controls the transcription factor involved in myogenesis and those involved in cell proliferation (Li et al., 1992). AP-1 is also one of the transcription factors binding in the promoter of FABP4 with CEBPa (Shin et al., 2009). Recently, the mutation of cholinergic receptor, nicotinic, epsilon (CHREN) is significantly associated with muscle growth in beef cattle from primer-extension assay (Sevane et al., 2011). These results indicate that the genes in the red module may function in regulating muscle growth or fat-related mechanisms and co-expressed genes with similar functions in the module. In addition, we explored regulatory relationships (i.e., common regulators and targets) between 15 direct-interacted genes using pathway studio. The common targets or regulators are shown in Figure 3 with the direct interaction relationship. We found the common regulators based on an assumption that the genes within a similar biological pathway are controlled by common regulators. E2F1 is one gene of the E2F family and is a candidate to be a transcription factor controlling corticotropin releasing hormone (CRH) for marbling and subcutaneous fat depth in beef cattle (Wibowo et al., 2007). In longissimus muscle tissue expression during growth in the porcine, E2F1 also showed a significant relationship with differential expressed genes as a transcription factor with myogenin and PAX3 (D'Andrea et al., 2011). In our network analysis, E2F1 is a member of the red module and regulates FGFR2. The FGF family plays a role in cell growth, such as cell proliferation and angiogenesis. The FGFR2 protein is induced in the mid-to-late G1 phase of the cell cycle by E2F1 (Tashiro et al., 2003).

Finally, we investigated the functional bias of the significant genes according to GO classification and understood the biological significance of the module genes, and determined the putative pathways using DAVID. Table 4 lists the significant gene ontology terms and the representative genes. Due to the incomplete annotation of the bovine genome, 168 of 222 probe sets were annotated (Table 4). In significant GO terms of Biological processes, the regulation of biological quality (GO:0065008) indicates that the process modulates a measuable attribute of an organism or part of an organism, such as size, mass, shape, color, etc. This result is also reflected in the pathway analysis. The term is included in 5 pathway hub genes (IL6, CHRNE, RB1, INHBA and NPPA) of 12 annotated genes by gene ontology. Collagen, type IX, alpha 1 (COL9A1) is detected in the other genes. Significant associations of the COL9A1 gene with body length, depth and width have previously been reported in pigs. Recently, it has also been related to logissimus muscle area from assocation analysis in the pig (Fan et al., 2009). These findings suggest that genes in the red module tend to be highly enriched with meat quality and have a potential role to change or control a specific phenotype for animal production.

CONCLUSION

A major objective of this study was to construct the gene co-expression network and then to find hub modules or genes associated with the marbling score. Therefore, we attempted to find coexpression patterns associated with marbling in Hanwoo (Korean cattle) by the WGCNA method. As a result, three large co-expression modules were significantly associated with marbling score and intramuscular fat. Among these three modules, we focused on the red module for functional enrichment analysis. This is because the tan and lightcyan modules have not shown a significant correlation between gene significance and module membership in each module. Through the pathway and gene ontology analysis, we consistently observed that hub genes within the red module were predominantly a co-expression group having biological pathways related to skeletal muscle. We noticed overlapping genes from the analysis, and five genes (IL6, CHRNE, RB1, INHBA and NPPA) belonged to a red module. These genes are shared in skeletal muscle related biological pathways that might represent a phenomenon occuring in muscle with highly divergent marbling phenotype as key drives. Our results do not point to a single biological pathway or candidate gene like a standard differential expression analysis. Instead, we find several highly significant biological pathways and patterns of co-expressed genes as key drivers in the marbling score related modules. These results will provide valuable information for the additional biological study of meat quality in Hanwoo (Korean cattle).

http://dx.doi.org/10.5713/ajas.2012.12375

REFERENCES

Al-Khalili, L., K. Bouzakri, S. Glund, F. Lonnqvist, H. A. Koistinen and A. Krook. 2006. Signaling specificity of interleukin-6 action on glucose and lipid metabolism in skeletal muscle. Mol. Endocrinol. 20:3364-3375.

Brem, R. B., G. Yvert, R. Clinton and L. Kruglyak. 2002. Genetic dissection of transcriptional regulation in budding yeast. Science 296:752-755.

Chen, P. L., D. J. Riley, Y. Chen and W. H. Lee. 1996. Retinoblastoma protein positively regulates terminal adipocyte differentiation through direct interaction with C/EBPs. Genes Dev. 10:2794-2804.

Crews Jr, D., E. Pollak, R. Weaber, R. Quaas and R. Lipsey. 2003. Genetic parameters for carcass traits and their live animal indicators in Simmental cattle. J. Anim. Sci. 81:1427-1433.

D'Andrea, M., S. Dal Monego, A. Pallavicini, M. Modonut, R. Dreos, B. Stefanon and F. Pilla. 2011. Muscle transcriptome profiling in divergent phenotype swine breeds during growth using microarray and RT PCR tools. Anim. Genet. 42:501-509

Davies, J. D., K. L. Carpenter, I. R. Challis, N. L. Figg, R. McNair, D. Proudfoot, P. L. Weissberg and C. M. Shanahan. 2005. Adipocytic differentiation and liver x receptor pathways regulate the accumulation of triacylglycerols in human vascular smooth muscle cells. J. Biol. Chem. 280:3911-3919.

Dewey, F. E., M. V. Perez, M. T. Wheeler, C. Watt, J. Spin, P. Langfelder, S. Horvath, S. Hannenhalli, T. P. Cappola and E. A. Ashley. 2011. Gene coexpression network topology of cardiac development, hypertrophy, and failure clinical perspective. Circ. Cardiovasc. Genet. 4:26-35.

Donaldson, L., T. Vuocolo, C. Gray, Y. Strandberg, A. Reverter, S. McWilliam, Y. Wang, K. Byrne and R. Tellam. 2005. Construction and validation of a bovine innate immune microarray. BMC Genomics 6:135.

Fan, B., S. Onteru, M. Nikkila, K. Stalder and M. Rothschild. 2009. The COL9A1 gene is associated with longissimus dorsi muscle area in the pig. Anim. Genet. 40:788.

Florini, J. R., D. S. Samuel, D. Z. Ewton, C. Kirk and R. M. Sklar. 1996. Stimulation of myogenic differentiation by a neuregulin, glial growth factor 2. Are neuregulins the long-sought muscle trophic factors secreted by nerves? J. Biol. Chem. 271:12699-12702.

Fuller, T. F., A. Ghazalpour, J. E. Aten, T. A. Drake, A. J. Lusis and S. Horvath. 2007. Weighted gene coexpression network analysis strategies applied to mouse weight. Mamm. Genome 18:463-472.

Gautier, L., L. Cope, B. Bolstad and R. Irizarry. 2004. Affy-analysis of Affymetrix GeneChip data at the probe level. Bioinformatics 20:307-315.

Ghazalpour, A., S. Doss, B. Zhang, S. Wang, C. Plaisier, R. Castellanos, A. Brozell, E. E. Schadt, T. A. Drake and A. J. Lusis. 2006. Integrating genetic and network analysis to characterize genes related to mouse weight. PLoS Genet. 2: e130.

Gibson, G. and B. Weir. 2005. The quantitative genetics of transcription. Trends Genet. 21:616-623.

Grefte, S., A. M. Kuijpers-Jagtman, R. Torensma and J. W. Von den Hoff. 2007. Skeletal muscle development and regeneration. Stem Cells Dev. 16:857-868.

Haley, C. and D. J. de Koning. 2006. Genetical genomics in livestock: potentials and pitfalls. Anim. Genet. 37(Suppl 1):10-12.

Harper, G., D. Pethick, V. Oddy, R. Tume, W. Barendse and L. Hygate. 2001. Biological determinants of intramuscular fat deposition in beef cattle: current mechanistic knowledge and sources of variation. Meat Livest. Australia, Sydney.

Hocquette, J., F. Gondret, E. Baeza, F. Medale, C. Jurie and D. Pethick. 2010. Intramuscular fat content in meat-producing animals: development, genetic and nutritional control, and identification of putative markers. Animal 4:303-319.

Horvath, S. and J. Dong. 2008. Geometric interpretation of gene coexpression network analysis. PLoS Comput. Biol. 4: e1000117.

Irizarry, R. A., B. M. Bolstad, F. Collin, L. M. Cope, B. Hobbs and T. P. Speed. 2003. Summaries of Affymetrix GeneChip probe level data. Nucleic Acids Res. 31:e15.

Jiang, Z., J. J. Michal, J. Chen, T. F. Daniels, T. Kunej, M. D. Garcia, C. T. Gaskins, J. R. Busboom, L. J. Alexander and R. W. Wright. 2009. Discovery of novel genetic networks associated with 19 economically important traits in beef cattle. Int. J. Biol. Sci. 5:528-542.

Kim, N. K., D. Lim, S. H. Lee, Y. M. Cho, E. W. Park, C. S. Lee, B. S. Shin, T. H. Kim and D. Yoon. 2011. Heat shock protein B1 and its regulator genes are negatively correlated with intramuscular fat content in the Longissimus thoracis muscle of Hanwoo (Korean Cattle) steers. J. Agric. Food Chem. 25:5657-5664.

Kokta, T., M. Dodson, A. Gertler and R. Hill. 2004. Intercellular signaling between adipose tissue and muscle tissue. Domest. Anim. Endocrinol. 27:303-331.

Lebrasseur, N. K., G. M. Cote, T. A. Miller, R. A. Fielding and D. B. Sawyer. 2003. Regulation of neuregulin/ErbB signaling by contractile activity in skeletal muscle. Am. J. Physiol. Cell Physiol. 284:C1149-1155.

Lee, S. H., C. Gondro, J. van der Werf, N. K. Kim, D. Lim, E. W. Park, S. J. Oh, J. Gibson and J. Thompson. 2010. Use of a bovine genome array to identify new biological pathways for beef marbling in Hanwoo (Korean Cattle). BMC Genomics 11: 623.

Lee, S. H., E. W. Park, Y. M. Cho, S. K. Kim, J. H. Lee, J. T. Jeon, C. S. Lee, S. K. Im, S. J. Oh and J. M. Thompson. 2007. Identification of differentially expressed genes related to intramuscular fat development in the early and late fattening stages of hanwoo steers. J. Biochem. Mol. Biol. 40:757-764.

Li, L., J. C. Chambard, M. Karin and E. N. Olson. 1992. Fos and Jun repress transcriptional activation by myogenin and MyoD: the amino terminus of Jun can mediate repression. Genes Dev. 6:676-689.

Li, Y., Z. Xu, H. Li, Y. Xiong and B. Zuo. 2010. Differential transcriptional analysis between red and white skeletal muscle of Chinese Meishan pigs. Int. J. Biol. Sci. 6:350-360.

Lim, D., N. K. Kim, H. S. Park, S. H. Lee, Y. M. Cho, S. J. Oh, T. H. Kim and H. Kim. 2011. Identification of candidate genes related to bovine marbling using protein-protein interaction networks. Int. J. Biol. Sci. 7:992-1002.

McIntyre, B. A. S., P. Brouillard, V. Aerts, I. Gutierrez-Roelens and M. Vikkula. 2004. Glomulin is predominantly expressed in vascular smooth muscle cells in the embryonic and adult mouse. Gene Expr. Patterns 4:351-358.

Miller, J. A., M. C. Oldham and D. H. Geschwind. 2008. A systems level analysis of transcriptional changes in Alzheimer's disease and normal aging. J. Neurosci. 28:1410-1420.

Moore, S. S. and E. F. Marques. 2008. Associations of polymorphisms in the fibroblast growth factor 8 (FGF8) and its haplotypes with carcass quality, growth and feed efficiency in beef cattle, Google Patents.

Nikitin, A., S. Egorov, N. Daraselia and I. Mazo. 2003. Pathway studio-the analysis and navigation of molecular networks. Bioinformatics 19:2155-2157.

Nobis, W., X. Ren, S. P. Suchyta, T. R. Suchyta, A. J. Zanella and P. M. Coussens. 2003. Development of a porcine brain cDNA library, EST database, and microarray resource. Physiol. Genomics 16:153-159.

Oldham, M. C., S. Horvath and D. H. Geschwind. 2006. Conservation and evolution of gene coexpression networks in human and chimpanzee brains. Proc. Natl. Acad. Sci. 103: 17973-17978.

Park, B., A. D. Whittaker, R. K. Miller and D. S. Hale. 1994. Predicting intramuscular fat in beef longissimus muscle from speed of sound. J. Anim. Sci. 72:109-116.

Peter, L. and H. Steve. 2008. WGCNA: an R package for weighted correlation network analysis. BMC Bioinformatics 9:599

Ravasz, E., A. Somera, D. Mongru, Z. Oltvai and A. Barabasi. 2002. Hierarchical organization of modularity in metabolic networks. Science 297:1551-1555.

Reverter, A., N. Hudson, Y. Wang, S. Tan, W. Barris, K. Byrne, S. McWilliam, C. Bottema, A. Kister and P. Greenwood. 2006. A gene coexpression network for bovine skeletal muscle inferred from microarray data. Physiol. Genomics 28:76-83.

Rhoads, R. P., M. E. Fernyhough, X. Liu, D. C. McFarland, S. G. Velleman, G. J. Hausman and M. V. Dodson. 2009. Extrinsic regulation of domestic animal-derived myogenic satellite cells II. Domest. Anim. Endocrinol. 36:111-126.

Rosenthal, S. M. and Z. Q. Cheng. 1995. Opposing early and late effects of insulin-like growth factor I on differentiation and the cell cycle regulatory retinoblastoma protein in skeletal myoblasts. Proc. Natl. Acad. Sci. 92:10307-10311.

Saris, C. G., S. Horvath, P. W. van Vught, M. A. van Es, H. M. Blauw, T. F. Fuller, P. Langfelder, J. DeYoung, J. H. Wokke, J. H. Veldink. 2009. Weighted gene co-expression network analysis of the peripheral blood from Amyotrophic Lateral Sclerosis patients. BMC Genomics 10:405.

Schadt, E. E., S. A. Monks, T. A. Drake, A. J. Lusis, N. Che, V. Colinayo, T. G. Ruff, S. B. Milligan, J. R. Lamb and G. Cavet. 2003. Genetics of gene expression surveyed in maize, mouse and man. Nature 422:297-302.

Sevane, N., I. Crespo, J. Canon and S. Dunner. 2011. A Primer-Extension Assay for simultaneous use in cattle Genotype Assisted Selection, parentage and traceability analysis. Livest. Sci. 137:141-150.

Shin, J., B. Li, M. E. Davis, Y. Suh and K. Lee. 2009. Comparative analysis of fatty acid-binding protein 4 promoters: conservation of peroxisome proliferator-activated receptor binding sites. J. Anim. Sci. 87:3923-3934.

Sibut, V., C. Hennequet-Antier, E. Le Bihan-Duval, S. Marthey, M. J. Duclos and C. Berri. 2011. Identification of differentially expressed genes in chickens differing in muscle glycogen content and meat quality. BMC Genomics 12:112.

Smith, G. W. and G. J. Rosa. 2007. Interpretation of microarray data: trudging out of the abyss towards elucidation of biological significance. J. Anim. Sci. 85(13 Suppl):E20-E23.

Su, H. Y., T. J. Bos, F. S. Monteclaro and P. K. Vogt. 1991. Jun inhibits myogenic differentiation. Oncogene 6:1759-1766.

Suarez, E., D. Bach, J. Cadefau, M. Palacin, A. Zorzano and A. Guma. 2001. A novel role of neuregulin in skeletal muscle. Neuregulin stimulates glucose uptake, glucose transporter translocation, and transporter expression in muscle cells. J. Biol. Chem. 276:18257-18264.

Subramanian, A., P. Tamayo, V. K. Mootha, S. Mukherjee, B. L. Ebert, M. A. Gillette, A. Paulovich, S. L. Pomeroy, T. R. Golub and E. S. Lander. 2005. Gene set enrichment analysis: a knowledge-based approach for interpreting genome-wide expression profiles. Proc. Natl. Acad. Sci. 102:15545-15550.

Tashiro, E., Y. Minato, H. Maruki, M. Asagiri and M. Imoto. 2003. Regulation of FGF receptor-2 expression by transcription factor E2F-1. Oncogene 22:5630-5635.

Wayne, M. L. and L. M. McIntyre. 2002. Combining mapping and arraying: An approach to candidate gene identification. Proc. Natl. Acad. Sci. USA. 99:14903-14906.

Wibowo, T. A., J. J. Michal and Z. Jiang. 2007. Corticotropin releasing hormone is a promising candidate gene for marbling and subcutaneous fat depth in beef cattle. Genome 50:939-945.

Ye, Y. and A. Godzik. 2004. Comparative analysis of protein domain organization. Genome Res. 14:343-353.

Dajeong Lim (1,2), Seung-Hwan Lee (1), Nam-Kuk Kim (3), Yong-Min Cho (1), Han-Ha Chai (1), Hwan-Hoo Seong (1) and Heebal Kim (2), *

(1) National Institute of Animal Science, RDA, Suwon, Korea

(2) Department of Food and Animal Biotechnology, Seoul National University, Seoul, Korea

(3) National Agricultural products Quality management Service(NAQS), Seoul, Korea

* Corresponding Author: Heebal Kim. Tel: +82-2-880-4803, Fax: +82-2-873-2271, E-mail: heebal@snu.ac.kr

Submitted Jul. 6, 2012; Accepted Aug. 7, 2012; Revised Sept. 26, 2012

Table 1. Summary statistics of tissue sample
for weighted gene co-expression network
analysis

Group   Animal   Marbling   IMF content
          ID      score         (%)

Low      509        2          7.11
         537        2          6.02
         554        3          4.88
         670        3          7.36
         691        3          12.04
High     527        7          24.35
         547        7          32.49
         586        7          16.56
         589        7          26.24
         632        7          18.81

Table 2. The significant relationship between modules and
phenotipyc variables

Module Eigengene    Significant traits (correlation r, p-value)

MEred              Marbling score (r = 0.77, p = 0.009),
                   Intramuscular fat (r = 0.72, p = 0.02), Water
                   holding capacity (r = 0.79, p = 0.006)
MEtan              Marbling score (r = 0.66, p = 0.03),
                   Intramuscular fat (r = 0.74, p = 0.01), Meat
                   color CIE L (r = 0.62, p = 0.05)
MElightcyan        Marbling score (r = 0.66, p = 0.04)
MEsamon            Shear force (r = 0.67, p = 0.04)
MEyellow           Shear force (r = 0.69, p = 0.03)
MEblack            Intramuscular fat (r = 0.69, p = 0.03), Meat
                   color CIE b (r = 0.63, p = 0.05)
Megreenyellow      Age (r = 0.75, p = 0.01)

Table 3. The significant genes in the red, tan and
lightcyan modules for marbling score

Probe                Gene symbol    Gene title

Bt.25404.2.S1_at         GLMN       Glomulin, FKBP associated protein
Bt.22038.1.S1_a_at       RARS       Arginyl-trna synthetase
Bt.3670.1.A1_at           --        --
Bt.6338.1.S1_at         FERMT2      Fermitin family homolog 2
                                    (Drosophila)
Bt.1020.1.S1_at          CLK1       CDC-like kinase 1
Bt.17136.1.A1_at          --        --
Bt.7018.1.S1_at        TXNDC13      Thioredoxin domain containing 13
Bt.18891.1.S1_at        ERGIC3      ERGIC and golgi 3
Bt.27173.1.S1_at     C10H15orf44    Chromosome 15 open reading frame
                                    44 ortholog
Bt.28784.1.A1_at          --        --
Bt.5194.3.S1_a_at        WBP1       WW domain binding protein 1
Bt.26240.1.S1_at         FHIT       Fragile histidine triad gene
Bt.11239.3.S1_at         SPG7       Spastic paraplegia 7 (pure and
                                    complicated autosomal recessive)
Bt.6611.1.S1_at           --        --
Bt.23995.1.A1_at        STK38L      Serine/threonine kinase 38 like
Bt.20287.2.S1_at         SHF        Src homology 2 domain
                                    containing F
Bt.19321.1.A1_at          --        --
Bt.9267.1.A1_at        APOBEC3B     Apolipoprotein B mrna editing
                                    enzyme, catalytic
                                    polypeptide-like 3B
Bt.26711.2.S1_at        LRRC20      Leucine rich repeat containing 20
Bt.13637.1.A1_at        SULF2       Sulfatase 2
Bt.14036.1.S1_at         PCNT       Pericentrin
Bt.24716.1.S1_at         - -        --
Bt.2507.1.S1_at         SFRS10      Splicing factor, arginine/
                                    serine-rich 10 (transformer 2
                                    homolog, Drosophila)
Bt.20134.1.S1_at         CPN1       Carboxypeptidase N, polypeptide 1
Bt.21563.2.A1_at        SLC8A3      Solute carrier family 8 (sodium/
                                    calcium exchanger), member 3
Bt.27673.1.A1_at          --        --
Bt.17725.1.A1_at          --        --
Bt.5807.1.S1_at           --        --
Bt.28732.1.S1_s_at    LOC407199     T cell receptor delta chain
Bt.28732.1.S1_at         TRD        T-cell receptor delta chain
Bt.7484.1.S1_at        PLEKHG2      Pleckstrin homology domain
                                    containing, family G (with RhoGef
                                    domain) member 2
                         LRG1       Leucine-rich alpha-2
                                    -glycoprotein 1
Bt.13062.1.A1_at        COL9A1      Collagen, type IX, alpha 1
Bt.20189.1.S1_at        FTSJD2      FtsJ methyltransferase domain
                                    containing 2
Bt.27184.1.S1_at       HISPPD2A     Histidine acid phosphatase domain
                                    containing 2A
Bt.5892.1.S1_at        C6orf25      Chromosome 6 open reading
                                    frame 25
Bt.27974.1.S1_at         NRG1       Neuregulin 1
Bt.26693.1.S1_at          --        --
Bt.4189.1.S1_a_at       GHRHR       Growth hormone releasing hormone
                                    receptor
Bt.20361.1.S1_at        FBXL20      F-box and leucine-rich repeat
                                    protein 20
Bt.29696.1.A1_at        FGFR2       fibroblast growth factor
                                    receptor 2
Bt.16351.1.A1_at        WDR20       WD repeat domain 20
Bt.3233.1.A1_at         CIAO1       Cytosolic iron-sulfur protein
                                    assembly 1 homolog (S.
                                    cerevisiae)
Bt.28236.1.A1_at        ATP4A       ATPase, H+/K+ exchanging, alpha
                                    polypeptide
Bt.17742.1.A1_at          --        --
Bt.20225.1.S1_at        DTNBP1      Dystrobrevin binding protein 1
BtAffx.1.9.S1_at         NPPA       Natriuretic peptide precursor A
Bt.19219.1.S1_at          --        --
Bt.5386.1.S1_at         COBRA1      Cofactor of BRCA1
Bt.25049.1.S1_at       TRAM1L1      Translocation associated membrane
                                    protein 1-like 1
Bt.13929.2.S1_at         DPH3       DPH3, KTI11 homolog (S.
                                    cerevisiae)
Bt.25510.1.S1_at      LOC513740     Hypothetical LOC513740
Bt.12404.1.S1_at       CLPTM1L      CLPTM1-like
Bt.17824.2.A1_at        VPS36       Vacuolar protein sorting 36
                                    homolog (S. cerevisiae)
Bt.568.1.S1_at           IBSP       Integrin-binding sialoprotein
Bt.28987.1.S1_at          --        --
Bt.20942.1.S1_at          --        --
Bt.20198.1.S1_at       TUBGCP3      Tubulin, gamma complex associated
                                    protein 3
Bt.23135.1.S1_at        TAGLN2      Transgelin 2
Bt.26658.2.S1_at       SLC46A1      Solute carrier family 46 (folate
                                    transporter), member 1
Bt.8592.1.S1_a_at      PABPC1L      Poly(A) binding protein,
                                    cytoplasmic 1-like
Bt.8262.1.A1_at           --        --
Bt.28716.2.S1_at      LOC532698     Hypothetical protein LOC532698
Bt.27339.1.A1_at         MME        Membrane metallo-endopeptidase
Bt.18789.2.A1_at         ATF7       Activating transcription factor 7
Bt.11542.1.A1_at          --        --
Bt.286.1.S1_at         CACNA1B      Calcium channel, voltage
                                    -dependent, N type, alpha 1B
                                    subunit
Bt.18809.1.A1_at       SLC22A23     Solute carrier family 22, member
                                    23
Bt.21688.1.S1_at     LOC100196901   Hypothetical LOC100196901
Bt.6348.2.S1_at        DENND1A      DENN/MADD domain containing 1A
Bt.25454.1.A1_at          --        --
Bt.26290.2.S1_a_at       IPO4       Importin 4
Bt.27284.1.S1_at        EIF4H       Eukaryotic translation initiation
                                    factor 4H
Bt.24979.1.S1_at         CD1E       CD1e molecule
Bt.9785.1.S1_at           --        --
Bt.20768.1.S1_at      LOC529859     Similar to KIAA1632
Bt.26228.1.A1_at          --        --
Bt.27244.1.A1_at          --        --
Bt.9562.1.S1_at         SCN5A       Sodium channel, voltage-gated,
                                    type V, alpha subunit
Bt.16757.1.S1_at        DCP1A       DCP1 decapping enzyme homolog
                                    A (S. cerevisiae)
Bt.28733.1.S1_at        ZNF397      Zinc finger protein 397
Bt.12288.1.S1_at        NPBWR1      Neuropeptides B/W receptor 1
Bt.20833.1.S1_at        NHLRC2      NHL repeat containing 2
Bt.13608.1.A1_at          --        --
Bt.18127.1.A1_at        WDR87       WD repeat domain 87
Bt.4220.1.S1_at          PDPR       Pyruvate dehydrogenase
                                    phosphatase regulatory subunit
Bt.28106.1.S1_at          --        --
Bt.13948.1.S1_at          --        --
Bt.4250.2.S1_at          MAP4       Microtubule-associated protein 4
Bt.15740.1.A1_at       TPD52L1      Tumor protein D52-like 1
Bt.2132.1.A1_at         MCPH1       Microcephalin 1
Bt.19567.2.S1_at          --        --
Bt.11916.1.S1_at      LOC615412     Similar to BAI1-associated
                                    protein 2-like 1
Bt.524.1.S1_at          IL12A       Interleukin 12A (natural killer
                                    cell stimulatory factor 1,
                                    cytotoxic lymphocyte maturation
                                    factor 1, p35)
Bt.5561.1.S1_at          MC4R       Melanocortin 4 receptor
Bt.12854.1.S1_at         --         --
Bt.16977.1.A1_at         --         --
Bt.15432.1.A1_at         --         --
Bt.11730.1.A1_at         --         --
Bt.26030.1.A1_at         --         --
Bt.11794.1.S1_at        HIGD1A      HIG1 domain family, member 1A
Bt.7131.2.S1_at          PLDN       Pallidin homolog (mouse)
Bt.27873.1.S1_at         --         --

Probe                Gene symbol    p.GS.marbling   MMred
                                        score

Bt.25404.2.S1_at         GLMN           0.00        0.71
Bt.22038.1.S1_a_at       RARS           0.00        -0.68
Bt.3670.1.A1_at           --            0.00        0.87
Bt.6338.1.S1_at         FERMT2          0.00        -0.81
Bt.1020.1.S1_at          CLK1           0.00        -0.85
Bt.17136.1.A1_at          --            0.00        -0.81
Bt.7018.1.S1_at        TXNDC13          0.00        0.89
Bt.18891.1.S1_at        ERGIC3          0.00        0.76
Bt.27173.1.S1_at     C10H15orf44        0.00        -0.75
Bt.28784.1.A1_at          --            0.00        0.80
Bt.5194.3.S1_a_at        WBP1           0.00        0.79
Bt.26240.1.S1_at         FHIT           0.00        0.84
Bt.11239.3.S1_at         SPG7           0.01        -0.81
Bt.6611.1.S1_at           --            0.01        -0.85
Bt.23995.1.A1_at        STK38L          0.01        0.79
Bt.20287.2.S1_at         SHF            0.01        0.84
Bt.19321.1.A1_at          --            0.01        0.91
Bt.9267.1.A1_at        APOBEC3B         0.01        -0.91
Bt.26711.2.S1_at        LRRC20          0.01        -0.79
Bt.13637.1.A1_at        SULF2           0.01        -0.87
Bt.14036.1.S1_at         PCNT           0.01        -0.84
Bt.24716.1.S1_at          --            0.01        0.80
Bt.2507.1.S1_at         SFRS10          0.01        -0.88
Bt.20134.1.S1_at         CPN1           0.01        0.79
Bt.21563.2.A1_at        SLC8A3          0.01        0.88
Bt.27673.1.A1_at          --            0.01        0.78
Bt.17725.1.A1_at          --            0.01        -0.83
Bt.5807.1.S1_at           --            0.02        0.68
Bt.28732.1.S1_s_at    LOC407199         0.02        -0.76
Bt.28732.1.S1_at         TRD            0.02        -0.74
Bt.7484.1.S1_at        PLEKHG2          0.02        0.88
                         LRG1           0.02        -0.91
Bt.13062.1.A1_at        COL9A1          0.02        0.79
Bt.20189.1.S1_at        FTSJD2          0.02        -0.90
Bt.27184.1.S1_at       HISPPD2A         0.02        -0.84
Bt.5892.1.S1_at        C6orf25          0.02        0.70
Bt.27974.1.S1_at         NRG1           0.02        0.93
Bt.26693.1.S1_at          --            0.02        0.86
Bt.4189.1.S1_a_at       GHRHR           0.02        0.83
Bt.20361.1.S1_at        FBXL20          0.02        -0.80
Bt.29696.1.A1_at        FGFR2           0.02        0.76
Bt.16351.1.A1_at        WDR20           0.02        -0.78
Bt.3233.1.A1_at         CIAO1           0.02        -0.74
Bt.28236.1.A1_at        ATP4A           0.02        0.85
Bt.17742.1.A1_at          --            0.02        0.87
Bt.20225.1.S1_at        DTNBP1          0.02        -0.86
BtAffx.1.9.S1_at         NPPA           0.02        0.78
Bt.19219.1.S1_at          --            0.02        -0.87
Bt.5386.1.S1_at         COBRA1          0.02        -0.93
Bt.25049.1.S1_at       TRAM1L1          0.02        0.76
Bt.13929.2.S1_at         DPH3           0.02        -0.89
Bt.25510.1.S1_at      LOC513740         0.02        -0.69
Bt.12404.1.S1_at       CLPTM1L          0.03        -0.97
Bt.17824.2.A1_at        VPS36           0.03        -0.79
Bt.568.1.S1_at           IBSP           0.03        0.93
Bt.28987.1.S1_at          --            0.03        0.78
Bt.20942.1.S1_at          --            0.03        -0.81
Bt.20198.1.S1_at       TUBGCP3          0.03        -0.87
Bt.23135.1.S1_at        TAGLN2          0.03        0.85
Bt.26658.2.S1_at       SLC46A1          0.03        0.93
Bt.8592.1.S1_a_at      PABPC1L          0.03        0.82
Bt.8262.1.A1_at           --            0.03        -0.86
Bt.28716.2.S1_at      LOC532698         0.03        -0.84
Bt.27339.1.A1_at         MME            0.03        -0.74
Bt.18789.2.A1_at         ATF7           0.04        0.85
Bt.11542.1.A1_at          --            0.04        0.87
Bt.286.1.S1_at         CACNA1B          0.04        0.88
Bt.18809.1.A1_at       SLC22A23         0.04        0.79
Bt.21688.1.S1_at     LOC100196901       0.04        -0.72
Bt.6348.2.S1_at        DENND1A          0.04        0.88
Bt.25454.1.A1_at          --            0.04        0.79
Bt.26290.2.S1_a_at       IPO4           0.04        0.92
Bt.27284.1.S1_at        EIF4H           0.04        -0.89
Bt.24979.1.S1_at         CD1E           0.04        -0.83
Bt.9785.1.S1_at           --            0.04        -0.76
Bt.20768.1.S1_at      LOC529859         0.04        -0.85
Bt.26228.1.A1_at          --            0.04        0.84
Bt.27244.1.A1_at          --            0.04        0.69
Bt.9562.1.S1_at         SCN5A           0.04        0.92
Bt.16757.1.S1_at        DCP1A           0.04        0.78
Bt.28733.1.S1_at        ZNF397          0.05        -0.90
Bt.12288.1.S1_at        NPBWR1          0.05        0.77
Bt.20833.1.S1_at        NHLRC2          0.05        0.85
Bt.13608.1.A1_at          --            0.05        0.72
Bt.18127.1.A1_at        WDR87           0.05        0.76
Bt.4220.1.S1_at          PDPR           0.05        0.85
Bt.28106.1.S1_at          -             0.04        -0.96
Bt.13948.1.S1_at          -             0.04        0.71
Bt.4250.2.S1_at          MAP4           0.04        -0.70
Bt.15740.1.A1_at       TPD52L1          0.036       0.76
Bt.2132.1.A1_at         MCPH1           0.03        -0.89
Bt.19567.2.S1_at          -             0.03        -0.65
Bt.11916.1.S1_at      LOC615412         0.03        0.75
Bt.524.1.S1_at          IL12A           0.03        0.84
Bt.5561.1.S1_at          MC4R           0.02        0.88
Bt.12854.1.S1_at          --            0.02        -0.80
Bt.16977.1.A1_at          --            0.02        0.85
Bt.15432.1.A1_at          --            0.02        0.76
Bt.11730.1.A1_at          --            0.02        0.90
Bt.26030.1.A1_at          --            0.00        0.74
Bt.11794.1.S1_at        HIGD1A          0.00        0.84
Bt.7131.2.S1_at          PLDN           0.00        0.64
Bt.27873.1.S1_at          --            0.00        -0.65

Probe                Gene symbol    p.MM.red    Module

Bt.25404.2.S1_at         GLMN         0.02        Red
Bt.22038.1.S1_a_at       RARS         0.03
Bt.3670.1.A1_at           --          0.00
Bt.6338.1.S1_at         FERMT2        0.00
Bt.1020.1.S1_at          CLK1         0.00
Bt.17136.1.A1_at          --          0.00
Bt.7018.1.S1_at        TXNDC13        0.00
Bt.18891.1.S1_at        ERGIC3        0.01
Bt.27173.1.S1_at     C10H15orf44      0.01
Bt.28784.1.A1_at          --          0.01
Bt.5194.3.S1_a_at        WBP1         0.01
Bt.26240.1.S1_at         FHIT         0.00
Bt.11239.3.S1_at         SPG7         0.00
Bt.6611.1.S1_at           --          0.00
Bt.23995.1.A1_at        STK38L        0.01
Bt.20287.2.S1_at         SHF          0.00
Bt.19321.1.A1_at          --          0.00
Bt.9267.1.A1_at        APOBEC3B       0.00
Bt.26711.2.S1_at        LRRC20        0.01
Bt.13637.1.A1_at        SULF2         0.00
Bt.14036.1.S1_at         PCNT         0.00
Bt.24716.1.S1_at          --          0.01
Bt.2507.1.S1_at         SFRS10        0.00
Bt.20134.1.S1_at         CPN1         0.01
Bt.21563.2.A1_at        SLC8A3        0.00
Bt.27673.1.A1_at          --          0.01
Bt.17725.1.A1_at          --          0.00
Bt.5807.1.S1_at           --          0.03        Red
Bt.28732.1.S1_s_at    LOC407199       0.01
Bt.28732.1.S1_at         TRD          0.01
Bt.7484.1.S1_at        PLEKHG2        0.00
                         LRG1         0.00
Bt.13062.1.A1_at        COL9A1        0.01
Bt.20189.1.S1_at        FTSJD2        0.00
Bt.27184.1.S1_at       HISPPD2A       0.00
Bt.5892.1.S1_at        C6orf25        0.02
Bt.27974.1.S1_at         NRG1         0.00
Bt.26693.1.S1_at          --          0.00
Bt.4189.1.S1_a_at       GHRHR         0.00
Bt.20361.1.S1_at        FBXL20        0.01
Bt.29696.1.A1_at        FGFR2         0.01
Bt.16351.1.A1_at        WDR20         0.01
Bt.3233.1.A1_at         CIAO1         0.02
Bt.28236.1.A1_at        ATP4A         0.00
Bt.17742.1.A1_at          --          0.00
Bt.20225.1.S1_at        DTNBP1        0.00
BtAffx.1.9.S1_at         NPPA         0.01
Bt.19219.1.S1_at          --          0.00
Bt.5386.1.S1_at         COBRA1        0.00
Bt.25049.1.S1_at       TRAM1L1        0.01
Bt.13929.2.S1_at         DPH3         0.00
Bt.25510.1.S1_at      LOC513740       0.03
Bt.12404.1.S1_at       CLPTM1L        0.00
Bt.17824.2.A1_at        VPS36         0.01
Bt.568.1.S1_at           IBSP         0.00
Bt.28987.1.S1_at          --          0.01
Bt.20942.1.S1_at          --          0.00
Bt.20198.1.S1_at       TUBGCP3        0.00
Bt.23135.1.S1_at        TAGLN2        0.00
Bt.26658.2.S1_at       SLC46A1        0.00
Bt.8592.1.S1_a_at      PABPC1L        0.00
Bt.8262.1.A1_at           --          0.00
Bt.28716.2.S1_at      LOC532698       0.00
Bt.27339.1.A1_at         MME          0.01
Bt.18789.2.A1_at         ATF7         0.00
Bt.11542.1.A1_at          --          0.00
Bt.286.1.S1_at         CACNA1B        0.00
Bt.18809.1.A1_at       SLC22A23       0.01        Red
Bt.21688.1.S1_at     LOC100196901     0.02
Bt.6348.2.S1_at        DENND1A        0.00
Bt.25454.1.A1_at          --          0.01
Bt.26290.2.S1_a_at       IPO4         0.00
Bt.27284.1.S1_at        EIF4H         0.00
Bt.24979.1.S1_at         CD1E         0.00
Bt.9785.1.S1_at           --          0.01
Bt.20768.1.S1_at      LOC529859       0.00
Bt.26228.1.A1_at          --          0.00
Bt.27244.1.A1_at          --          0.03
Bt.9562.1.S1_at         SCN5A         0.00
Bt.16757.1.S1_at        DCP1A         0.01
Bt.28733.1.S1_at        ZNF397        0.00
Bt.12288.1.S1_at        NPBWR1        0.01
Bt.20833.1.S1_at        NHLRC2        0.00
Bt.13608.1.A1_at          --          0.02
Bt.18127.1.A1_at        WDR87         0.01        Tan
Bt.4220.1.S1_at          PDPR         0.00
Bt.28106.1.S1_at          --        1.59E-05
Bt.13948.1.S1_at          --          0.02
Bt.4250.2.S1_at          MAP4         0.03
Bt.15740.1.A1_at       TPD52L1        0.01
Bt.2132.1.A1_at         MCPH1         0.00
Bt.19567.2.S1_at          --          0.04
Bt.11916.1.S1_at      LOC615412       0.01
Bt.524.1.S1_at          IL12A         0.00
Bt.5561.1.S1_at          MC4R         0.00
Bt.12854.1.S1_at          --          0.01
Bt.16977.1.A1_at          --          0.00
Bt.15432.1.A1_at          --          0.01
Bt.11730.1.A1_at          --          0.00
Bt.26030.1.A1_at          --          0.01
Bt.11794.1.S1_at        HIGD1A        0.00
Bt.7131.2.S1_at          PLDN         0.05     Lightcyan
Bt.27873.1.S1_at          --          0.04

Table 4. Gene Ontology terms overrepresented in the
red module related to marbling score by DAVID tool

Category             GO terms           p-value

Biological   Transmembrane transport     0.012
             (GO:0055085)
process      Regulation of biological    0.041
             quality (GO:0065008)
             Salivary gland              0.047
             morphogenesis
             (GO:0007435)
Molecular    Protein binding             0.029
function     (GO:0005515)
             RNA binding                 0.046
             (GO:0003723)
Cellular     Phosphoglycolate            0.046
component    phosphatase activity
             (GO:0008967)
             Nuclear envelope            0.013
             (GO:0005635)
             Nuclear membrane            0.027
             (GO:0031965)
             Endomembrane system         0.035
             (GO:0012505)
             Nuclear pore                0.040
             (GO:0005643)

Category             GO terms                    Gene symbols

Biological   Transmembrane transport    CACNA1B,CNGB1,SCN5A,SLC8A3,
             (GO:0055085)               KCNH1,SLC46A1,ATP4A,RANBP2,
                                        TAP2,NUP85
process      Regulation of biological   DTNBP1,SLC9A3R1,CACNA1B,NPPA,
             quality (GO:0065008)       IL6,TXNDC 13,PCSK2,CHRNE,
                                        COL9A1,INHBA,APTX,RB1
             Salivary gland             IL6,FGFR2
             morphogenesis
             (GO:0007435)
Molecular    Protein binding            NPPA,FTSJD2,NUP85,LRRC20,
function     (GO:0005515)               CIAO1,SCN5A,PITPNA,CD3G,IBSP,
                                        RANBP2,VAPB,TAGLN2,ATF7,
                                        FBXL20,APTX,RB1,FABP5,BAIAP2,
                                        LMNA,KCNH1,C22H3 or f60,WBP1,
                                        JUN,TAF1B,JARID1C,CUL7,
                                        CXCL10,INHBA,MYLIP,DTNBP1,
                                        VPS45,MGC148992,VPS36,HIT,
                                        VPS26A,LRG1,SHF,DPH3,RAB7A,
                                        PCSK2,IL6,NPBWR1,FGFR2,
                                        CNPY3,TCHP
             RNA binding                ILF3 ,TRUB2 ,RBM18,EIF4H,
             (GO:0003723)               RPS20,CSTF2,SFRS10,APTXX
Cellular     Phosphoglycolate           PGP,APTX
component    phosphatase activity
             (GO:0008967)
             Nuclear envelope           TAGLN2,LMNA,IPO4,RANBP2,
             (GO:0005635)               NUP85
             Nuclear membrane           TAGLN2,LMNA,NUP85
             (GO:0031965)
             Endomembrane system        TAGLN2,LMNA,IPO4,RANBP2,
             (GO:0012505)               ST3GAL2,VPS26A,NUP85,VAPB
             Nuclear pore               IPO4,RANBP2,NUP85
             (GO:0005643)
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Author:Lim, Dajeong; Lee, Seung-Hwan; Kim, Nam-Kuk; Cho, Yong-Min; Chai, Han-Ha; Seong, Hwan-Hoo; Kim, Heeb
Publication:Asian - Australasian Journal of Animal Sciences
Article Type:Essay
Geographic Code:9SOUT
Date:Jan 1, 2013
Words:8619
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