Population genetic structure and genetic differentiation of Artemia parthenogenetica in China.

ABSTRACT Ten strains of Artemia parthenogenetica have been collected from inland salt lakes and coastal salterns in China. Ten diploid clones were selected from each Artemia parthenogenetica strain for analysis of the population genetic structure and genetic differentiation using inter simple sequence repeats (ISSR). One hundred and seventy fragments (100-2200 bp) were generated using 20 ISSR primers. A high level of genetic variation was found, with 96.47% polymorphic loci in total loci. The number of alleles (Na), effective number of alleles (Ne) and Shannon information index (SI), the mean Nei's gene diversity (H), the average values of Ht, Hs, Gst for pairwise subpopulations and mean value of all 100 clones from 10 Chinese Artemia parthenogenesis strains were analyzed. The results showed that genetic structure of populations of A. parthenogenetica from China were complicated with high genetic diversity among the populations. Cluster analysis was then performed to create a dendrogram using the UPGMA method based on the Nei' genetic identity. The UPGMA dendrogram showed that 10 Chinese Artemia parthenogenetica strains can be significantly divided into three major groups (subpopulation): Liaoning, (PK and YK); Shandong and Hebei, (HH, TG, LN, WD, WZ and FC) and Qinghai and Xinjiang (GH and BLK).

KEY WORDS: Artemia parthenogenetica, ISSR, genetic structure, genetic differentiation

INTRODUCTION

Brineshrimp, Artemia (Crustacea Anostraca), are widely distributed in inland salt lakes and coastal salterns over the world. Populations of the genus Artemia were found in more than 600 habitats dispersed across the world (Van Stappen 2002). The genus Artemia comprises a complex of bisexual species defined by the criterion of reproductive isolation and of a large number of parthenogenetic populations under the binomen A. parthenogenetica, composed of diploid and polyploidy individuals for taxonomic convenience (Sun et al. 1999). The Morphological study (Triantaphyllidis et al. 1994), genetic variation (Zhang & King 1992) and evolution of most parthenogenetic Artemia populations have been examined by means of allozyme electrophoresis, karyotype, high repeat sequence (Abreu-Grobois & Beardmore 1980, 1982, 1983, 1991; Beardmore & Abreau-Grobois 1983, Badaracco et al. 1991, Bowen et al. 1988, Barigozzi, 1974, Barigozzi et al. 1987, Hou et al. 1993, 2000), molecular markers such as RAPD and AFLP (Camargo et al. 2002, Sun et al. 2000). In China, A. parthenogenetica is found in either saltworks along the coast of Bohai sea or salt lake from Qinghai, Xinjiang (Wang et al. 1991; Yang et al. 1995, 1996, Hou et al. 2000). The relationship with bisexual Artemia and expression of isozyme gene have been analyzed (Gao et al. 1994; Hou et al. 2003), but little is currently known about that population genetic structure and genetic differentiation of different geographic parthenogenetic Artemia strains in China.

Molecular genetic information has been increasingly used to detect the population genetic structure and genetic diversity among morphologically similar populations of a same species. Of the many molecular approaches available today, the simple inter sequence repeats (ISSR) technique is among the most sensitive. The ISSR technique had been successfully used to reveal population genetic structure and relationship (Kantety et al. 1995, Nagaoka & Ogihara 1997, Martin & Sanchez-Ye1amo 2000) and genetic diversity(Awasthi et al. 2004; Brantestam et al. 2004). The ISSR primer sequences are designed from microsatellite regions and the annealing temperatures used are higher than those used for RAPD markers, which have better reliability. Also, the technique does not require prior knowledge of DNA sequence for primer design, which is more practical (Wolfe et al. 1998).

In this study, the molecular marker of ISSR was used to help analyze the population genetic structure and genetic diversity of Artemia parthenogenetica in China. The Chinese Artemia parthenogenetic populations along the coastal of Bohai sea are all diploid (Pilla 1992, Triantaphyllidis et al. 1997) with the exception of Huanghua (Hebei Province) where a few tetraploid individuals appeared, and there are also a few triploid, tetraploid and pentaploid individuals that appeared in Balikun saltlake and Aibi saltlake in the Xinjiang autonomous region; therefore only diploid clones are being studied.

MATERIALS AND METHODS

Anemia cysts of 10 geographic strains of A. parthenogenetica were collected directly from different areas in China, followed by their code abbreviations (used hereafter), is as follows: Balikun, Xinjing Autonomous Region (BLK); Gahai, Qinghai Province (GH); Wudi, Shandong Province (WD); Yingkou, Liaoning Province (YK); Tanggu, Tianjin (TG); Luannan, Hebei Province (LN); Pikou, Liaoning Province (PK); Huanghua, Hebei Province (HH); Fengcheng, Shandong Province (FC); Wuzhi, Shandong Province (WZ) (Table 1).

The nauplii were hatched from the cysts of different strains according to the methods described by Sorgeloos et al. (1986). The nauplii were cultured for 15 days to adulthood in the laboratory, fed on Dunaliella salina, then 30 single individual clones were created from each strain according to the methods described by Hou et al. (2000), and 300 clones were obtained from 10 strains. The ploidy of clones was examined using the methods described by Cai and Hou (1991) and Yang et al. (1996), 10 diploid clones were selected from 30 clones in each strain, and 100 clones were obtained from 10 strains. The individuals of 100 diploid clones were used for DNA extraction.

DNA Extraction

Artemia genomic DNA used for ISSR analysis was isolated as described by Sun (1999) with some modifications: (1) after removing the digestive tract, each individual was directly immersed in a 200-[micro]L solution (100 [mML.sup.-1] EDTA, 10 [mML.sup.-1] Tris-HCl), containing 25 [micro]L 10% SDS and 10 [micro]L 20 mg [mL.sup.-1] proteinase K; (2) the incubated temperature was increased to 60[degrees]; (3) non purified DNA was directly extracted and used to ISSR amplification. After isolation, DNA was stored in 10-[micro]L TE solution. DNA quality and quantity were determined by 0.8% agarose gel electrophoresis.

ISSR PCR Amplification

Twenty ISSR primers were synthesized from Saibaisheng Inc based on core repeats (Zietkiewicz et al. 1994), anchored either at the 5' or 3' end (Table 2). All ISSR primers were evaluated for their ability to produce polymorphic bands.

ISSR amplifications was performed by using the ISSR primers in a 20 [micro]L reaction volume containing 2.0 [micro]L x 10 buffer, 1.25 [micro]L of 25 mM Mg[Cl.sub.2], 2 [micro]L of 10 mM dNTP, 1.0 [micro]L of primer at 10 pM, 5-10 ng DNA template, and 0.5 [micro]L of Taq DNA polymerase (Takara Inc) and 20 [micro]L water volume. An initial 5 min denaturation at 94[degrees]C was followed by 45 cycles of 94[degrees]C denaturation for 30 s, 52[degrees]C annealing for 45 s, 72[degrees]C extension for 2.0 min. Amplification cycles were followed by a final 7 rain extension at 72[degrees]C. Amplification was carried out with a PCR Express machine (ThermoHybaid, Needham Heights, MA). The size and quality of PCR products were determined on 2.0% agarose gels. Molecular weights were estimated using DL2000 DNA marker (Takara Inc).

Data Analysis

Data were scored in function of the presence (1) or absence (0) of every amplification product, and the data were entered into a data matrix. Based on data matrix of ISSR, Nei's (1978) genetic identity (I) (1978) and Nei's genetic distances (D) (1987) between geographical strains were analyzed. Measurements of diversity including gene diversity (H) at each locus; observed number of alleles (Na); effective number of alleles (Ne) and Shannon information index (SI); gene differentiation ([G.sub.st]), according to McDermott and McDonald (1993), were estimated using the POPGENE 1.32 statistical package. Based on the matrix of genetic identity (Nei 1978) cluster analyses were performed using unweighted pair/group method with arithmetic averages (UPGMA) (Sneath & Sokal 1973). The dendrogram was constructed by software PHYLIP 3.5c neighbor and TreeView l.66.

RESULTS

Using 20 ISSR primers we detected 170 bands of which 164 were polymorphic (96.47%). The level of polymorphism for each primer is quite variable, ranging from 54.12 per cent (in GH strain) to 55.10 per cent (87.06) (in PKstrain). Band size ranged from 100-2200 bp. Representative ISSR fingerprints obtained with primer [(AC).sub.8]T are shown in Figure 1.

[FIGURE 1 OMITTED]

Population Genetic Structure

Table 3 showed the number of polymorphic loci and percentage polymorphic loci, mean observed number of alleles (Na), mean effective number of alleles (Ne), mean Nei's gene diversity (H) and mean Shannon's Information index (I) in the 100 clones from 10 Chinese Artemia parthenogenetic strains. The observed number of alleles (Na) ranged from 1.8706 (PK) to 1.5412 (GH), mean value of Na was 1.7571. Compared with Na, the Ne values (effective number of alleles) were lower, which ranged from 1.2557 (GH) to 1.6219 (LN). The Nei's gene diversity (H) ranged from 0.1551(GH) to 0.3476 (LN), mean Nei's gene diversity was 0.2925. Shannon's Information index (SO estimated a measure of intrapopulation diversity, the highest value (0.5050) was found in the LN strain and the lowest value was 0.2398 in the GH strain, mean value was 0.4292. The Nei's genetic identity (I) and genetic distance (D) are examined for all pairwise comparisons between the subpopulations (Table 4). The genetic distances for all comparisons range from 0.0352 (between HH and TG) to 0.3353 (between YK and GH). The Nei's genetic identity among these 10 Artemia parthenogenetic strains (subpopulations) range from 0.7151 (YK/GH) to 0.9654(TG/HH). The UPGMA dendrogram of Nei's genetic identity for 10 Chinese Artemia parthenogenetic strains showed that different geographic parthenogenetic strains were divided into 3 groups (subpopulation): Liaoning Province; Shandong and Hebei Province and Qinghai and Xinjiang (Fig. 2).

[FIGURE 2 OMITTED]

Genetic Diversity and Genetic Differentiation

Table 5 shows the total variation ([H.sub.t]), the average variation within populations ([H.sub.s]) and gene differentiation ([G.sub.st]) for pairwise strains and mean value of Hr Hs and Gst of all 100 clones from 10 Chinese Artemia parthenogenetica strains. The highest [H.sub.t] value (0.3902) is found between LN and BLK strains, and the lowest value is 0.2639 between WZ and FC strains. The mean value of [H.sub.t] from 100 clones was 0.3895, indicating that about 38.95 percent of genetic variation among the different strains. The Hs value is variable, ranges from 0.3459 (LN/PK) to 0.1853 (WZ/GH), with the mean value of Hs 100 clones was 0.2925. The values of gene differentiation (Gst) of 100 clones from 10 Chinese Artemia parthenogenetica strains range from 0.3464 (WZ/GH) to 0.0674 (WZ/ FC), the mean value was 0.2492. The regression line based on, [log.sub.10] Gst values and [log.sub.10] Km (geographical distance) pairwise among 10 subpopulations of Artemia parthenogenetica, is plotted by SPSS software. There is a significant correlation of t-test of regression coefficient (t = 7.7887, P = 0.0001). The regression equation is LogGst = 0.2677 Log Km - .5679, [R.sup.2] = 0.5909.

DISCUSSION

ISSR has been successfully used to reveal genetic variation in silkworm (Pradeep et al. 2005), in aphids (Abbot, 2001) and in Fenneropenaeus chinensis shrimp (Wang & Kong, 2002), to characterize genome diversity (Yang et al. 1996), and to determine the origin of hybrids (Wolfe et al. 1998). The primers are anchored at their 3' end, to ensure that the annealing of the primer occurs only at the 3' or 5' end of the microsatellite motif, thus obviating internal priming and smear formation. The anchor also allows only a subset of the targeted inter-repeat regions to be amplified, thereby reducing the high number of PCR products expected from the priming of dinucleotide inter-repeat regions to a set of about 10-50 easily resolvable bands. Pattern complexity can be tailored by applying different primer lengths and sequences (Zietkiewicz et al. 1994). Based on its unique characters, the ISSR technique can detect more genetic loci than isozyme and has higher stability than RAPD. This is the first report of using ISSR markers in surveying genetic structure and differentiation in Artemia parthenogenetica. ISSR fingerprints clearly distinguished all the tested Artemia parthenogenetica populations. The experimental results show high genetic diversity and difference among 10 different geographic strains (subpopulation) of A. parthenogenetica in China. There are high proportions (96.47%) of polymorphic loci, indicating the higher-level variation in the 10 different geographic strains. Nascetti et al. (2003) and Hou et al. (1993) by isozymes and Sun et al. (2000) by AFLP and RAPD found high levels of genetic diversity, high levels of genetic variability and high proportions of polymorphic loci in parthenogenetic populations, although different molecular marker techniques were used in the experiments the conclusions were the same. Based on our experimental data earlier, we supported their opinions of high-level genetic diversity and high proportion of polymorphic loci in Artemia parthenogenetic populations. Nascetti et al. (2003) reported high levels of heterozygosity of A. parthenogenetica populations from Italy arranged from 0.135-0.185 by isozymes. In this study, because of limitation of the ISSRs technique, heterozygosity of different geographic populations was not calculated.

The UPGMA dendrogram based on Nei's genetic identity for Chinese Artemia parthenogenetic strains showed that different geographic parthenogenetic strains can be divided into three groups (subpopulation): Liaoning Province, group of Shandong and Hebei Province; Qinghai Province and Xinjiang Autonomous Region. Moreover, compared with the inland saltlake group of Qinghai and Xinjiang, the coastal groups, which included the groups of the Liaoning and Shandong and Hebei Province have a closer

relationship. In agreement, the AFLP marker (Sun 1999) showed that A. parthenogenetica from inland and coastal origin, group into two different clusters, and allozyme analysis (Gao et al. 1994) also indicate that there is a significant difference between the populations from coastal China (Huanghua, Hebei province, and Dalian, Liaoning province) and from inland salt lakes (Xinjiang Autonomous Region). Hence, the parthenogenetic populations from inland salt lakes could have followed an evolutionary path that is different from that of the coastal parthenogenetic populations, or the large genetic differences possibly occur because of geographic isolation. To explore the reason for relationships among different strains, we introduce the parameter of Gst (Nei & Chakraborty 1973). Gst, which can be used to explain the population genetic differentiation, is equivalent to Fst (Wright, 1951) when there are only two alleles at a locus, and, in the case of multiple alleles; Gst is equivalent to the weighted average of Fst for all alleles (Nei & Chakraborty 1973). In this study, we did not find statistics data of Gst value in other strains, therefore Gst was compared with Fst of different geographic strains. The Gst value (0.3464) is higher within distant geographic subpopulations (WZ/ BLK), average value is 0.2492, implying a higher genetic differentiation among populations. The Gst values (0.036-0.3464) of A. parthenogenetica in China is higher than that of the Chinese bisexual populations of Artemia (Fst, 0.0024-0.1297) (Xin et al. 2000), which revealed that high differentiation level among A. parthenogenetica within population (clones) (24.92% of variation within population and 75.08% of variations among populations of A.parthenogenetica). The adverse surroundings conditions in habitats of Artemia populations (shortage of food, higher salinity, irregular temperature) could result in higher levels of genetic diversity, differentiation and polymorphic phenomena in A. parthenogenetica populations, and selection plays an important role in the processes (Bowen et al. 1988, Browne & Hoopes 1990, Lenz & Browne 1991, Browne 1992, Hou et al. 1993, Nascetti et al. 2003). Meanwhile, the different environmental conditions could be responsible for selective fixation in heterozygosity of many loci and for high genetic divergence observed between either diploid/ polyploidy or polyploidy populations (Barigozzi 1974, Nascetti et al. 2003). Once heterozygosity originates, it could maintain through selective pressure caused by environmental conditions (Zhang & King 1992). Although the earlier-mentioned hypothesis is supported by experimental results of Nascetti et al. (2003), Hou et al. (1993) and Zhang and King (1992) the formation mechanism of high levels of genetic diversity of A. parthenogenetica needs to be explored further.

Population genetic structure and Gst values can be changed by migration among individuals of different populations. Artemia cysts were suited for passive dispersal by wind, waterfowl or man (Persoone & Sorgeloos 1980), this passive migration may change gene diversity (Gst and Fst) and gene flow (Nm). In this study, the reasons for causing high-level genetic variations in population could be migration. We estimated the relationship Gst (intrapopulation genetic variations) and geographic distance (Fig. 3). Figure 3 shows, a clear tendency for higher Gst value with far geographical distance (Km) and revealed high genetic differentiations with far geographical distance. The Cause for high level genetic differentiation was that geographic distance plays an important role in Artemia cysts dispersal, cysts were difficult to disperse alone in long distances. The genetic differentiation (Gst) levels among these subpopulations raise with the increasing geographical distance, therefore the high Gst levels may be results of genetic isolation by a geographical distance barrier. Conversely, WZ, FC and WD have a short geographic distance, and individuals of different populations may exchange very frequently by migration. Gst values of WZ, FC and WD were low, which indicates the presence of low level genetic differentiations among these subpopulations. Although the gene flow could not be estimated among Artemia parthenogenetic strains, genetic differentiations among different strains may be affected by a geographical isolation barrier and migrating by birds, wind, workers of salt works and others (Andy et al. 2005; Browne et al. 1993).

[FIGURE 3 OMITTED]

In recent years, a large amount of male individuals (40% and above) were found in A. parthenogenetica from the Chinese coastal salt works, it was believed that this was caused by ecological invasion of A. franciscana or A. sinica, because cysts of A. franciscana or A. sinica were introduced into these salterns for aquaculture. The samples in this study were collected before ecological invasion occurred, so it is important to know basal data of the population genetic structure and done diversity of A. parthenogenetica from China. Taxonomic status of invader and population genetic structure need to be studied further.

ACKNOWLEDGMENTS

The authors thank Prof. Cai Hanjun for providing us with cysts of the Wuzi, Wudi and Huanghua strains and Sarah E. James Roger McMurray, Holly E. Snow and Wan-Xi Yang for their critical reading of this manuscript. This project was supported by The National Nature Science Foundation of China (No.30271035, 39870118).

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HOU LIN, (1) * LI HAI-YAN, (1) ZOU XIANG-YANG, (2) YAO FENG, (1) BI XIANG-DONG (3) AND HE CHONG-BO (4)

(1) College of Sciences, Liaoning Normal University, Dalian 116029, People's Republic of China; (2) Department of Biology, Dalian Medical University, Dalian 116027, People's Republic of China; (3) Fisheries Science Department, Tianjin Agricultural University, Tianjin 300384, People's Republic of China; (4) Liaoning Ocean and Fisheries Science Research Institute, Dalian 116023, People's Republic of China

* Corresponding author. E-mail: [e-mail]

TABLE 1.
Samples of Artemia parthenogenetica for present study

Abbreviation   Location                          Collection
                                                    Time

    BLK        Balikun, Xinjing, China           2002.9
     GH        Gahai, Qinghai Prov., China       1999.9
     WD        Wudi, Shandong Prov., China       2002.9
     YK        Yingkou, Liaoning Prov., China    2000.9
     TG        Tanggu, Tianjin, China            2001.9
     LN        Luannan, Hebei Prov., China       2000.9
     PK        Pikou, Liaoning Prov. China       2002.9
     HH        Huanghua, Hebei Prov., China      2002.9
     FC        Fengcheng, Shandong Prov. China   2001.9
     WZ        Wuzhi, Shandong Prov., China      2002.9

TABLE 2.
List of primers used for ISSR amplification

Primer    Sequence             Primer    Sequence
          (5'-3')                        (5'-3')

ISSR-1    B*DB [(TCC).sub.5]   ISSR-11   [(AG).sub.8]TG
ISSR-2    [(TCC).sub.5]RY **   ISSR-12   [(TC).sub.8]C
ISSR-3    VBV [(CA).sub.8]     ISSR-13   [(TG).sub.8]G
ISSR-4    VDV [(GT).sub.8]     ISSR-14   [(CA).sub.6]R
ISSR-5    [(AG).sub.8]T        ISSR-15   [(CA).sub.6]RY
ISSR-6    HVH [(TG).sub.7] T   ISSR-16   [(GT).sub.6]YR
ISSR-7    [(CT).sub.8]A        ISSR-17   [(GT).sub.6]AY
ISSR-8    [(AC).sub.8]T        ISSR-18   [(ACTG).sub.4]
ISSR-9    [(AC).sub.8]G        ISSR-19   [GACA).sub.4]
ISSR-10   [(TG).sub.8]GT       ISSR-20   [(CAC).sub.6]

** Y = C T; R = A G; H = A C T; B = C G T; V = A C G; D= A G T.

TABLE 3.
Summary of populaton genetic structure for all loci

          No.
Strains   Clones             Na (*)                    Ne

WD        10        1.7706 [+ or -] 0.4217   1.5532 [+ or -] 0.3756
WZ        10        1.6353 [+ or -] 0.4828   1.3665 [+ or -] 0.3739
FC        10        1.7412 [+ or -] 0.4393   1.4914 [+ or -] 0.3976
TG        10        1.7882 [+ or -] 0.4098   1.5547 [+ or -] 0.3727
HH        10        1.8294 [+ or -] 0.3773   1.6078 [+ or -] 0.3411
LN        10        1.8471 [+ or -] 0.3610   1.6219 [+ or -] 0.3456
YK        10        1.7588 [+ or -] 0.4291   1.5443 [+ or -] 0.3850
PK        10        1.8706 [+ or -] 0.3366   1.6063 [+ or -] 0.3318
BLK       10        1.7882 [+ or -] 0.4098   1.5556 [+ or -] 0.3510
GH        10        1.5412 [+ or -] 0.4998   1.2557 [+ or -] 0.3350
Mean      100       1.7571 [+ or -] 0.1000   1.5157 [+ or -] 0.1173

Strains             H                        SI

WD        0.3108 [+ or -] 0.1917   0.4530 [+ or -] 0.2680
WZ        0.2156 [+ or -] 0.1964   0.3249 [+ or -] 0.2784
FC        0.2768 [+ or -] 0.2014   0.4076 [+ or -] 0.2786
TG        0.3124 [+ or -] 0.1893   0.4565 [+ or -] 0.2630
HH        0.3421 [+ or -] 0.1734   0.4972 [+ or -] 0.2420
LN        0.3476 [+ or -] 0.1720   0.5050 [+ or -] 0.2372
YK        0.3041 [+ or -] 0.1977   0.4427 [+ or -] 0.2754
PK        0.3443 [+ or -] 0.1645   0.5040 [+ or -] 0.2250
BLK       0.3162 [+ or -] 0.1850   0.4616 [+ or -] 0.2603
GH        0.1551 [+ or -] 0.1846   0.2398 [+ or -] 0.2645
Mean      0.2925 [+ or -] 0.0620   0.4292 [+ or -] 0.0855

          No. Polymorphic
Strains   Loci (percentage)

WD        131 (77.06%)
WZ        108 (63.53%)
FC        126 (74.12%)
TG        134 (78.82%)
HH        141 (82.94%)
LN        144 (84.71%)
YK        129 (75.8 (*)%)
PK        148 (87.06%)
BLK       134 (78.82%)
GH        92 (54.12%)
Mean      164 (96.47%)

* Na = Observed number of alleles; Ne = Effective number of alleles
[Kimura and Crow (1964)]; H

Nei's (1973) gene diversity; SI = Shannon's

Information index [Lewontin (1972)]; [See Nei (1987) Molecular
Evolutionary Genetics (p. 176-187)]

TABLE 4.
Nei's genetic identity (above diagonal) and genetic
distance (below diagonal)

      WD       WZ       FC       TG       HH

WD     ****    0.8940   0.9392   0.9015   0.9125
WZ    0.1121    ****    0.9536   0.9125   0.8996
FC    0.0627   0.0475    ****    0.9054   0.9023
TG    0.1037   0.0915   0.0994    ****    0.9654
HH    0.0916   0.1058   0.1028   0.0352    ****
LN    0.0930   0.1204   0.1130   0.1019   0.0487
YK    0.1890   0.1717   0.1539   0.1509   0.1665
PK    0.1016   0.1608   0.1076   0.1550   0.1403
BLK   0.1559   0.2726   0.2262   0.2183   0.1860
GH    0.2695   0.2753   0.2833   0.2713   0.2587

      LN       YK       PK       BLK      GH

WD    0.9112   0.8278   0.9034   0.8557   0.7637
WZ    0.8866   0.8422   0.8515   0.7614   0.7593
FC    0.8932   0.8573   0.8980   0.7976   0.7533
TG    0.9031   0.8599   0.8564   0.8039   0.7624
HH    0.9525   0.8466   0.8691   0.8302   0.7720
LN     ****    0.8352   0.8668   0.8257   0.7618
YK    0.1801    ****    0.9196   0.7822   0.7151
PK    0.1430   0.0838    ****    0.8342   0.7251
BLK   0.1915   0.2456   0.1813    ****    0.8266
GH    0.2721   0.3353   0.3214   0.1904    ****

TABLE 5.
Nei's analysis of gene diversity in subpopulations

           No.
Strains   clones             Ht                       Hs

WD-FC       20     0.3153 [+ or -] 0.0388   0.2938 [+ or -] 0.0340
WD-TG       20     0.3455 [+ or -] 0.0279   0.3116 [+ or -] 0.0258
WD-WZ       20     0.3029 [+ or -] 0.0355   0.2632 [+ or -] 0.0285
WD-HH       20     0.3560 [+ or -] 0.0260   0.3264 [+ or -] 0.0245
WD-LN       20     0.3591 [+ or -] 0.0246   0.3292 [+ or -] 0.0235
WD-YK       20     0.3670 [+ or -] 0.0224   0.3074 [+ or -] 0.0219
WD-BLK      20     0.3630 [+ or -] 0.0235   0.3135 [+ or -] 0.0226
WD-GH       20     0.3251 [+ or -] 0.0293   0.2329 [+ or -] 0.0196
WZ-FC       20     0.2639 [+ or -] 0.0349   0.2462 [+ or -] 0.0319
WZ-TG       20     0.2968 [+ or -] 0.0333   0.2640 [+ or -] 0.0285
WZ-HH       20     0.3163 [+ or -] 0.0288   0.2788 [+ or -] 0.0246
WZ-LN       20     0.3237 [+ or -] 0.0293   0.2816 [+ or -] 0.0249
WZ-YK       20     0.3188 [+ or -] 0.0267   0.2598 [+ or -] 0.0208
WZ-PK       20     0.3346 [+ or -] 0.0239   0.2799 [+ or -] 0.0195
WZ-BLK      20     0.3541 [+ or -] 0.0262   0.2659 [+ or -] 0.0217
WZ-GH       20     0.2836 [+ or -] 0.0392   0.1853 [+ or -] 0.0194
FC-TG       20     0.3280 [+ or -] 0.0309   0.2946 [+ or -] 0.0276
FC-HH       20     0.3435 [+ or -] 0.0283   0.3094 [+ or -] 0.0254
FC-LN       20     0.3493 [+ or -] 0.0276   0.3122 [+ or -] 0.0248
FC-YK       20     0.3411 [+ or -] 0.0252   0.2904 [+ or -] 0.0219
FC-PK       20     0.3461 [+ or -] 0.0263   0.3105 [+ or -] 0.0235
FC-BLK      20     0.3678 [+ or -] 0.0271   0.2965 [+ or -] 0.0240
FC-GH       20     0.3135 [+ or -] 0.0331   0.2159 [+ or -] 0.0187
TG-HH       20     0.3390 [+ or -] 0.0298   0.3272 [+ or -] 0.0286
TG-LN       20     0.3625 [+ or -] 0.0255   0.3300 [+ or -] 0.0238
TG-YK       20     0.3567 [+ or -] 0.0246   0.3082 [+ or -] 0.0225
TG-PK       20     0.3766 [+ or -] 0.0199   0.3283 [+ or -] 0.0192
TG-BLK      20     0.3815 [+ or -] 0.0199   0.3143 [+ or -] 0.0204
TG-GH       20     0.3263 [+ or -] 0.0306   0.2337 [+ or -] 0.0207
HH-LN       20     0.3604 [+ or -] 0.0268   0.3449 [+ or -] 0.0253
HH-YK       20     0.3751 [+ or -] 0.0214   0.3231 [+ or -] 0.0210
HH-PK       20     0.3862 [+ or -] 0.0185   0.3432 [+ or -] 0.0181
HH-BLK      20     0.3861 [+ or -] 0.0172   0.3291 [+ or -] 0.0180
HH-GH       20     0.3365 [+ or -] 0.0256   0.2486 [+ or -] 0.0182
LN-YK       20     0.3815 [+ or -] 0.0200   0.3258 [+ or -] 0.0201
LN-PK       20     0.3895 [+ or -] 0.0172   0.3459 [+ or -] 0.0172
LN-BLK      20     0.3902 [+ or -] 0.0165   0.3319 [+ or -] 0.0176
LN-GH       20     0.3429 [+ or -] 0.0247   0.2513 [+ or -] 0.0169
YK-PK       20     0.3515 [+ or -] 0.0227   0.3242 [+ or -] 0.0220
YK-BLK      20     0.3853 [+ or -] 0.0176   0.3101 [+ or -] 0.0197
YK-GH       20     0.3406 [+ or -] 0.0281   0.2296 [+ or -] 0.0198
PK-BLK      20     0.3858 [+ or -] 0.0182   0.3302 [+ or -] 0.0183
PK-GH       20     0.3550 [+ or -] 0.0235   0.2497 [+ or -] 0.0173
BLK-GH      20     0.3037 [+ or -] 0.0279   0.2356 [+ or -] 0.0193
Mean*      100     0.3895 [+ or -] 0.0159   0.2925 [+ or -] 0.0125

Strains    Gst

WD-FC     0.0684
WD-TG     0.0982
WD-WZ     0.1312
WD-HH     0.0830
WD-LN     0.0833
WD-YK     0.1624
WD-BLK    0.1365
WD-GH     0.2834
WZ-FC     0.0674
WZ-TG     0.1109
WZ-HH     0.1184
WZ-LN     0.1300
WZ-YK     0.1849
WZ-PK     0.1635
WZ-BLK    0.2492
WZ-GH     0.3464
FC-TG     0.1021
FC-HH     0.0992
FC-LN     0.1063
FC-YK     0.1486
FC-PK     0.1027
FC-BLK    0.1939
FC-GH     0.3113
TG-HH     0.0346
TG-LN     0.0898
TG-YK     0.1359
TG-PK     0.1283
TG-BLK    0.1763
TG-GH     0.2837
HH-LN     0.0432
HH-YK     0.1387
HH-PK     0.1113
HH-BLK    0.1476
HH-GH     0.2612
LN-YK     0.1460
LN-PK     0.1118
LN-BLK    0.1494
LN-GH     0.2669
YK-PK     0.0777
YK-BLK    0.1950
YK-GH     0.3260
PK-BLK    0.1441
PK-GH     0.2966
BLK-GH    0.2240
Mean*     0.2492

The number of polymorphic loci is : 164

The percentage of polymorphic loci is : 96.47

Mean values of Ht, Hs and Gst of 100 clones from 10 chinese Artemia
parthenogenetica populations [See Nei (1987) Molecular Evolutionary
Genetics (p. 187-192)]