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Biochemistry and molecular biology.

Carcinogenicity of Pentachlorophenol on Invertebrate and Vertebrate Cells: In Vitro and in Vivo Studies. Angela Meyer, Stacie Valentine, Gary M. Lange, and Plammoottil V. Cherian, Saginaw Valley State University

Several substances such as pesticides, herbicides and other chemicals in the environment are known carcinogens. Although the level of these compounds may be small, in light of the new report of the scientific advisory subcommittee of American Cancer Society many of these pollutants need to be reassessed for their cancer risk. We have undertaken to study the effect of pentachlorophenol (PcP) on invertebrate and vertebrate cells in vitro and in vivo. Drosophila melanogaster embryonic cells were cultured in Snyder's medium. Cells were treated with PcP (5O[micro]g/L) after 24-48 hrs of growth. After another 24 hrs, the cells were smeared and stained to assess the morphologic characteristics.

Analysis of cells from the treated cells showed that nearly 25% of cells had abnormality indicative of transformation. These changes include unusually large cells, larger nucleus, multiple nuclei and darker chromatin which are characteristic of cancer cells. In the controls, no significant number of cells with such abnormalities was observed. The result of in vivo experiment in mice is being analyzed to correlate carcinogenic changes in tissues. Preliminary results confirm that even low level exposure to PcP can contribute to the cancer burden when large numbers of people are exposed.

Cloning the Bacillus thuringiensis Toxin Receptor of the Eastern Tent Caterpillar Malacosoma americanum. Ashley Zondlak and Tim Keeton, Alma College

We have initiated the cloning of a novel protein receptor for the Bacillus thuringiensis biopesticides using the forest pest Malacosoma americanum, the Eastern Tent Caterpillar (ETC), as our target insect. Several receptors from the insect Order Lepidoptera (butterflies and moths) have been reported, but the only forestry pest that has been studied so far is the Gypsy Moth. Completing this project will provide insights into the normal role for this protein and the mode of action of the BT toxins. The Eastern Tent Caterpillar has drawn attention due to its defoliation of trees in the United States, especially cherry, apple, crabapple, and maple trees. More recently, it has become a topic of interest in the study of mare reproductive loss syndrome (MRLS). Studies have indicated that horses exposed to environments infested with ETC suffer a higher than expected rate of miscarriages making this insect a concern for the nation's equine industries. In 2001/2002 the equine industry suffered economic losses of approximately $500 million due to MRLS.

Mitochondrial DNA Evidence Suggests West and East Eurasian Genetic Influences in Neolithic Europeans. Jeremy Newton and Alex Nikitin, Grand Valley State University

The analysis of nucleotide sequence polymorphism of mitochondria! DNA (mtDNA) is widely used to provide insight into phylogenetic relationships among human populations, including past migratory events and origins of modern humans. Molecular techniques that allow for the recovery of ancient DNA (aDNA) from human remains can he used to directly observe the genetic makeup of early human populations. However, contamination remains a major technical challenge despite the development of extensive quality-control regimens and molecular techniques designed to assess the authenticity of recovered genetic sequences. For this research study, ancient mtDNA from osteological samples of Neolithic populations from the North Pontic region (NPR) of southeast Europe was extracted and analyzed using advanced molecular genetics techniques, including PCR amplification, direct sequencing and cloning of the amplification products. Phylogenetic network analysis was utilized to compare Neolithic NPR to modern and ancient European, Mediterranean, and Central Asian populations. Relevant archeological and anthropological data were also analyzed in order to aid in the interpretation of phylogenetic and molecular genetic data. Ultimately, this research is intended to help improve existing sample authentication strategies to better understand the origins of founding migratory lineages in Neolithic NPR.

Molecular Genetic Analysis of Sperm Competition in an Endocrine Disrupted Environment. Tyler Beyett, Nancy Q. Lackey, Jordan Killop, and Gary M. Lange, Saginaw Valley State University

Atrazine is one of the most widely used herbicides in the United States. The chemical is a known estrogen mimic and is capable of altering the growth, development, and reproduction in a variety of organisms. Recent studies have shown that low-level chronic exposure to atrazine is capable of reversing sexual development in male frogs. Coupled with evidence of disrupted sperm competition in rats exposed to other endocrine disruptors, the effects of atrazine on sperm competition are of key interest, especially since the Great Lakes region is one of the most heavily contaminated regions in the nation. We report on a novel experimental design for assessing sperm competition using microsatellite analysis. Extracted DNA is analyzed for dinucleotide repeats with a Beckman-Coulter CEQ 8000 at three loci selected for their success in similar studies. Analysis of offspring genotypes is used to assess whether pre-zygotic sperm competition is being disrupted. This study is one of the first extensive examinations of sperm competition in the presence of endocrine disruptors, making the experimental design and results invaluable to the growing examination of the safety of endocrine disrupting compounds in the environment.

The Effects of Decosahexaenoic Acids on Inositol Metabolism in the Yeast Saccharomyces Cerevisiae. (Poster) Marlene Murray-Nseula, Andrews University

Bipolar disorder is a severe and chronic debilitating mental disorder affecting 1-3% of the population. It is ranked sixth worldwide among all medical disorders in years of life lost to death or disability. Omega-3-fatty acids have been shown to relieve symptoms of bipolar disorder and are not associated with the negative side effects of lithium and valproate- two of the commonly used drugs for treating the disorder. However, the mechanism of action of omega-3-fatty acids remains unknown. In this study, the effects of the omega-3-fatty acids docosahexaenoic acid and eicosapentaenoic acid on inositol metabolism was determined by observing their effects on growth of the yeast Saccharomyces Cerevisiae in the presence and absence of inositol. The results show that similar to lithium and valproate, growth inhibition by docosahexaenoic acid was increased in the absence of inositol while eicosapentaenoic acid had no effect on growth.

Thermal Acclimation of Skeletal Muscle Sarcoplasmic Reticulum Ca2+ATPase (SERCA) in Bluefin Tuna, Thunnus orientalis. (Poster) Tamara Bazoun and Jeffery Morrissette, Lawrence Technological University

Tunas are unique among fishes because they are endothermic. Tuna endothermy results from vasculature with elaborate retia mirabilia (counter-current heat exchangers) that conserve metabolic heat and elevate oxidative tissue temperatures. Archival tags indicate that bluefin tuna can maintain peritoneal and muscle temperatures up to 20oC above ambient water temperature. However, body temperature in bluefin is heterogeneous, with thermal excess being greatest in muscle near the backbone and decreasing in superficial muscle. The purpose of this study was to determine how superficial muscle can maintain similar contraction frequencies as deep muscle while working at colder temperatures. We hypothesize that superficial muscle must have cellular specializations particularly in the way Ca2+ cycles that allow contractions to continue in the cold. We isolated sarcoplasmic reticulum (SR) from deep and superficial muscle, and quantified SERCA expression using SDS-PAGE and Western blotting. Densitometry revealed a 1.7-fold increase in SERCA pump expression in superficial compared to deep muscle. Similarly, SR vesicle Ca2+ uptake studies revealed a 2-fold faster Ca2+ uptake rate in superficial muscle compared to deep. We suggest that higher expression of SERCA in bluefin tuna superficial muscle may be important for retaining adequate Ca2+ cycling and hence muscle contraction in the cold.
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Publication:Michigan Academician
Geographic Code:1USA
Date:Mar 22, 2013
Words:1222
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