Karyological and allozyme survey of the Common shrew, Sorex araneus, from Macedonia

Karyotype and genetic variation of the common shrew (Sorex araneus) from Mt. Pelister in southern Macedonia has been studied. Whereas all autosomes in the chromosomal set (2 n_a, = 28, the only present metacentrics being af, bc, jl, and tu) were of the standard type as well as the sex chromosomes X and Y₂ in males, the Y₁ chromosome was a small metacentric. This chromosomal feature is unique among the common shrew populations studied cytogenetically so far. Three out of 33 loci analysed (Sdh, 6Pgd, Mdh-1) were discriminant between the Mt. Pelister population and Sorex araneus from Slovenia and two loci (Est-3, Ada) were partially discriminant. A relatively high value of Nei's genetic distance (D = 0.137) confirms unique character of the Pelister population.     

Genetic diversity of six populations of Atractomorpha sinensis and Atractomorpha peregrina in Shanxi Province, China

Ten enzymes (AAT, CK, G3PDH, HEX, IDH, LDH, MDH, ME, PGI, PGM) were examined using horizontal starch gel electrophoresis to estimate the levels of genetic variation within and among six natural populations of two grasshopper species Atractomorpha sinensis and A. peregrina from Shanxi, China. The collecting sites were geographically distant from each other from south to north: Quwo district, Linfen city; Xiangyuan county, Changzhi; Jinyuan district, Taiyuan city; Yuanping county, Xinzhou city and Fanshi county of Xinzhou.A. sinensis showed 43 alleles at 16 loci but A. peregrine showed 39 alleles at 15 loci (Idh-1 was deficient). The zymograms showed that some common alleles were shared at several loci in these two species (Aat-1-b, Aat-2-b, G3pdh-a, Ck-1-b and Ldh-b). However, Hex-1-a, Hex-2-a, Hex-3-a, Idh-2-b, Mdh-2-b, Mdh-1-f, Pgi-b, Pgm-b had common alles in A. sinensis and Hex-1-b, Hex-2-b, Hex-3-b, Idh-2-a, Mdh-2-a, Mdh-1-d, Pgi-a, Pgm-c were of high frequency in A. peregrine instead. Most of the observed genotype frequencies were found to significantly deviate from the Hardy-Weinberg expectations in both species. A tendency of clinal distribution of allele frequency was observed at three loci. The frequency of the moderately migrating allele Me-c (0.318–0.740) in A. peregrina, Hex-1-a (0.800–1.000) and Ldh-b (0.487–0.750) in A. sinensis demonstrated increased frequency from north to south. Such tendency suggests that the allele frequency in these three loci may be correlated with the species’ geographic distributions. A. sinensis showed higher genetic diversity than A. peregrina as indicated by higher mean number of alleles per locus (A = 1.9–2.3 in A. sinensis and 1.7–2.2 in A. peregrina), percentage of polymorphic loci (56.3%–68.8% in A. sinensis and 43.8%–56.3% in A. peregrina), and the observed heterozygosities (H _o = 0.072–0.096 in A. sinensis and 0.70–0.107 in A. peregrina). The observed heterozygosities of the six populations were all noticeably lower than the Hardy-Weinberg expectations, mostly due to heterozygote deficiency in the populations of both species. The overall mean F _ST were small (F _ST = 0.045, P > 0.05 in A. sinensis populations and 0.087, P > 0.05 in A. peregrina populations). Nei’s genetic identity (I) estimates indicate low intraspecific (>0.95) but higher interspecific (0.377–0.447) genetic diversity. The cluster analysis based on modified Roger’s genetic distance (D) showed that the two species were divided into two branches. Both species are of limited dispersal capacity and a moderate geographical barrier might significantly restrict the gene exchange among populations, resulting in accumulation of local genetic differentiations. The A. sinensis populations used in this study were separated from each other by 155.2 to 271.4 km and the A. peregrina populations were separated from each other by 78.8 to 174.9 km with observable physical barriers. The allozyme data showed only minimal genetic differentiation at population level, most likely as a result of gene exchange. It is reasoned that natural factors and human agricultural activities might have facilitated migration and dispersal for the two species. __________ Translated from Acta Ecologica Sinica, 2005, 25(10): 2574–2481 [译自: 生态学报]     

PATTERNS OF REPRODUCTION,GENETIC DIVERSITY,AND GENETIC DIFFERENTIATION IN CALIFORNIA POPULATIONS OF THE GENICULATE CORALLINE ALGA LITHOTHRIX ASPERGILLUM (RHODOPHYTA)1

The reproductive composition and genetic diversity of populations of the red seaweed Lithothrix aspergillum Gray (O. Corallinales) were studied at three southern California sites (Shaw's Cove and Treasure Island, Laguna Beach; Indian Rock, Santa Catalina Island) and at a fourth site (Bodega Bay) located in northern California. Sexually reproducing populations were confined to southern California. Diploid individuals were numerically dominant over haploid (gametophytic) individuals at all sites. Intertidal and subtidal subpopulations from Shaw's Cove differed in their reproductive profiles. Most intertidal specimens found on emersed surfaces were densely branched, turf-forming, and bore tetrasporangial (68.6%), carposporangial (11.4%), or spermatangial (5.7%) conceptacles, reflecting a sexual life history; none produced asexual bispores. In contrast, 74.3% of the larger, loosely branched subtidal specimens bore bisporangial conceptacles indicative of asexual reproduction. Nearly 70% of the Indian Rock thalli showed no evidence of conceptacle formation. Only asexual, diploid bispore-producing thalli were obtained from the Bodega Bay site. Genetic diversity (mean number of alleles per locus, percent of polymorphic loci, and average expected heterozygosity) of diploid L. aspergillum populations varied with life-history characteristics and geographic location. A total of 30 alleles was inferred from zymograms of 16 loci examined by starch-gel electrophoresis; of these loci, 11 were polymorphic. The genetic diversity of sexual, diploid populations of L. aspergillum (alleles per locus [A/L] = 1.4-1.5; percent polymorphic loci [%P] = 37.5-50.0) was relatively high compared with other red seaweeds. Lowest diversity (A/L = 1.0; %P = 0.0) occurred in the exclusively asexual Bodega Bay population which consisted of genetic clones. All sexual L. aspergillum populations deviated significantly from Hardy-Wein-berg expectations due to lower than expected heterozygosity. Genetic differentiation (Wright's F_statistic [F_ST]; Nei's Genetic Distance [D]) among sexually reproducing southern California populations was low (F_ST= 0.030) on a local scale (ca. 5 km), suggesting high levels of gene flow, but high genetic differention (F_ST= 0.390 and 0.406) occurred among southern California populations separated by ca. 70 km. Very high genetic differentiation (F_ST= 0.583–0.683) was obtained between northern and southern California populations separated by 700–760 km. Our genetic and reproductive data suggest that the L. aspergillum population from Bodega Bay is sustained by perennation, vegetative propagation, or asexual reproduction by bispores and may represent an isolated remnant or a population established by a founder event.     

Allozyme differentiation of populations of the dogwhelk Nucella lapillus, (L.): the relative effects of geographic distance and variation in chromosome number

Geographic patterns of genie differentiation were compared with differentiation between karyotypes in the intertidal snail Nucella lapillus. Samples from 24 sites covering the species range in Europe and North America were analysed for allozyme variation at 16 soluble enzyme loci. Two homokaryotypes have been identified with diploid numbers 2n = 26 and 2n= 36 (variation is Robertsonian and hybrids have intermediate chromosome numbers) and samples were classified (on the basis of published data) according to karyotype. Group 1 consisted of samples from three English Channel populations of higher chromosome number (on average 2n > 32) and Group 2 consisted of the remaining 21 samples (presumed to be 2n= 26). Karyotype variation accounts for roughly the same amount of the absolute allozyme variance as geographic variation (46.3 °, and 53.7°, respectively). Yet the patterns of differentiation seen between karyotypes and with geographic separation are very different. In samples classified as 2n= 26 (Group 2), while there is a significant amount of heterogeneity (F_ST per locus averaged 0.128 for 10 polymorphic loci), allozyme variation occurs independently at different loci so mean genetic identity (Nei) is high: 0.972. There is only a slight decline in genetic identity with distance (genetic identity averaged 0.965 for amphi-atlantic comparisons) indicating that passive transport of juveniles or adults may contribute significantly to gene flow. Conversely, allozyme variation between karyotypes was concordant. High chromosome number populations possessed a suite of alleles at four allozyme loci (Esl-3, Lap-2, Mdh-1 and Pep-2) which were absent or rare in Group 2 samples resulting in high F_ST values for these loci (from 0.294 to 0.472) when karyotypic classes were combined. Consequently the mean genetic identity between these Robertsonian races is low, 0.856, and falls within the range more usually associated with congeneric comparisons than with con-specific comparisons. The mechanisms maintaining this genie difference are unclear. However the distribution of the karyotypes and physiological and morphological differences (in shell shape) between them strongly suggest that karyotypic variation in Nucella is adaptive.     

Allozyme diversity in Chinese,Seguin and American chestnut (Castanea spp.)

Allozyme genetic variability in three chestnut (Castanea) species was investigated using 19 loci from ten enzyme systems. G-tests of heterogeneity of isozymic allele distribution showed significant differences between the three species at 15 of the 19 loci, and between the 13 C. mollissima populations at 13 of the 19 loci examined. C. mollissima was found to possess a significantly-higher value of mean gene heterozygosity (H=0.3050±0.0419), the percentage of polymorphic loci (P=84.21%) and the average number of alleles per locus (A=2.05), than any other species in the Castanea section Eucastanon. When the genetic variability of populations of C. mollissima from four regions in China was investigated, the population from the Changjiang river region showed a markedly higher mean gene heterozygosity (H=0.3480±0.0436) than populations from the other regions. Genetic relationships among the four regions were assessed by Nei's genetic identity I and standard genetic distance D. An approximately-identical distance between the population from the Changjiang river region and populations from the three other regions was observed, while populations from the latter regions showed almost the same genetic distance from each other. These data, when considered with information existing prior to this study, contribute to an understanding of the possible origin and progenitor of the chestnut species.     

Genetic diversity of six populations of Atractomorpha sinensis and Atractomorpha peregrina in Shanxi Province, China

Ten enzymes (AAT,CK,G3PDH,HEX,IDH,LDH,MDH,ME,PGI,PGM)were examined using horizontal starch gel electrophoresis to estimate the levels of genetic variation within and among six natural populations of two grasshopper species Atractomorpha sinensis and A.peregrina from Shanxi,China.The collecting sites were geographically distant from each other from south to north:Quwo district,Linfen city;Xiangyuan county,Changzhi;Jinyuan district,Taiyuan city;Yuanping county,Xinzhou city and Fanshi county of Xinzhou.A.sinensis showed 43 alleles at 16 loci but A.peregrine showed 39 alleles at 15 loci (ldh-1 was deficient).The zymograms showed that some common alleles were shared at several loci in these two species (Aat-1-b,Aat-2-b,G3pdh-a,Ck-1-b and Ldh-b).However,Hex-1-a,Hex-2-a,Hex-3-a,Idh-2-b,Mdh-2-b,Mdh-1-f Pgi-b,Pgm-b had common alleles in A.sinensis and Hex-1-b,Hex-2-b,Hex-3-b,Idh-2-a,Mdh-2-a,Mdh-1-d,Pgi-a,Pgm-c were of high frequency in A.peregrine instead.Most of the observed genotype frequencies were found to significantly deviate from the Hardy-Weinberg expectations in both species.A tendency of clinal distribution of allele frequency was observed at three loci.The frequency of the moderately migrating allele Me-c (0.318-0.740)in A.peregrina,Hex-1-a (0.800-1.000)and Ldh-b (0.487-0.750)in A.sinensis demonstrated increased frequency from north to south.Such tendency suggests that the allele frequency in these three loci may be correlated with the species'geographic distributions.A.sinensis showed higher genetic diversity than A.peregrina as indicated by higher mean number of alleles per locus (A=1.9-2.3 in A.sinensis and 1.7-2.2 in A.peregrina),percentage of polymorphic loci (56.3%-68.8%in A.sinensis and 43.8%-56.3%in A.peregrina),and the observed heterozygosities (Ho=0.072-0.096 in A.sinensis and 0.070-0.107 in A.peregrina).The observed heterozygosities of the six populations were all noticeably lower than the Hardy-Weinberg expectations,mostly due to heterozygote deficiency in the populations of both species.The overall mean Fsr were small (FST=0.045,P＞0.05 in A.sinensis populations and 0.087,P＞0.05 in A.peregrina populations).Nei's genetic identity (I)estimates indicate low intraspecific (＞0.95)but higher interspecific (0.377-0.447)genetic diversity.The cluster analysis based on modified Roger's genetic distance (D)showed that the two species were divided into two branches.Both species are of limited dispersal capacity and a moderate geographical barrier might significantly restrict the gene exchange among populations,resulting in accumulation of local genetic differentiations.The A.sinensis populations used in this study were separated from each other by 155.2 to 271.4 km and the A.peregrina populations were separated from each other by 78.8 to 174.9 km with observable physical barriers.The aUozyme data showed only minimal genetic differentiation at population level,most likely as a result of gene exchange.It is reasoned that natural factors and human agricultural activities might have facilitated migration and dispersal for the two species.     

Genetic diversity and multilocus associations in Cunninghamia lanceolata (Lamb.) Hook from The People's Republic of China

Open-pollinated seeds were assayed for allozyme polymorphisms at 24 loci to assess genetic diversity and multilocous associations in 16 populations of Cunninghamia lanceolata (Lamb.) Hook in the People's Republic of China. On average, the percentage of polymorphic loci was 88.0, the number of alleles per locus was 3.0, and the expected heterozygosity was 0.394. The distribution of genetic diversity was not correlated with the geographic and climatic variables of the populations. However, allele frequencies correlated linearly with the mean annual temperature of the populations at Mdh-1, Mdh-2, Mnr-2, Pgi-1, and Skdh-1 and with the altitude of the populations at Aph-4 and 6Pg-2. Of the total gene diversity 6% was attributed to among-population differentiation; 94% resided within populations. Two-locus gametic disequilibria were found in 15 of the 16 populations, and higher-order gametic disquilibria were significant in most populations. The gametic disequilibria did not correlate with geographic and climatic variables. The results suggest that population subdivision, founder effect, occurrence across diverse environments, a mating system dominated by inbreeding, and historical events from 2000 years of cultivation are contributing factors in the generation and maintenance of the multilocus genetic structure in this conifer.     

Genetics and polymorphism of a duplicated malate dehydrogenase (MDH) locus in the grasshopperOxya japonica japonica (Orthoptera:Acrididae:Oxyinae)

A biochemical genetic study of the enzyme malate dehydrogenase (MDH) was conducted in the grasshopperOxya j. japonica. Analysis of MDH electrophoretic variation in this species of grasshopper shows that one of the two autosomal loci for MDH in grasshoppers, the Mdh-2 locus, controlling the anodal set of MDH isozymes, is duplicated. Results of breeding studies confirm this and the observed polymorphism at theMdh-2 locus in the two populations ofOxya j. japonica studied can be attributed to three forms of linked alleles at the duplicated locus in equilibrium in both populations. In this respect, all individuals of this species possess heterozygous allelic combinations at the duplicatedMdh-2 locus, which may account for the spread of the duplicated locus in the populations of this species of grasshopper.This research was supported by a grant (Vote F) from the University of Malaya, Kuala Lumpur.     

The karyotypes of Dugesia species from Spain (Turbellaria,Tricladida)

Some species of Planarians, new to Spain, are recorded. Dugesia polychroa, D. sicula, D. iberica and D. gonocephala s. 1. have been investigated karyologically. The former possesses a diploid complement characteristic of the biotype A (2n = 8); the second is diploid with 2n = 18; diploidy and triploidy were found in sexual populations of D. iberica with n = 8. Triploidy occurred in all the asexual strains of the D. gonocephala group with a basic number of either 8 or 9. In this latter case B-chromosomes were occasionally found.     

宽翅曲背蝗两个地理种群等位酶的比较

采用水平淀粉凝胶电泳技术及应用等位酶分析方法,研究我国河北黄骅、辽宁葫芦岛宽翅曲背蝗两个自然种群的遗传多样性和遗传分化。在检测的11种酶15个酶基因座位中,Adk-I、Fbp-I、Mdh-2和G3pd-I基因座位的等位基因少,而Fbp-2、Mdh-I和Me-I基因座位的等位基因多。对每个基因座位的各基因型进行χ^2检验,除Mdh-I在辽宁葫芦岛种群、Adk-I在河北黄骅种群分别符合Hardy-Weinberg平衡外,其余绝大多数基因座位的基因型频率显著偏离Hardy-Weinberg平衡。两个种群之间存在明显的遗传多样性和分化：多态位点百分率分别为100％和93．3％,等位基因平均数分别为3．1和2．5,平均杂合度观测值分别为0．086和0．061。与其他非迁飞性蝗虫如中华稻蝗(Oxya chinensis)比较,这种蝗虫种群的平均杂合度较低但遗传多态性较高。结果表明：该蝗虫较强的跳跃能力可使个体暴露于各种不同环境,有利于维持种内遗传多态性的动态平衡,而种群保持较高的遗传多态性能增强该物种在不同栖息地的生存和繁殖能力。F-统计量表明两个种群之间的遗传分化相对较小,但这种分化显著高于迁飞性蝗虫如东亚飞蝗(Locusta migratoria manilensis)。Nei的遗传一致度(I)和Roger的遗传距离(D)的结果分析揭示了两个种群之间较高的遗传一致度(I=0．904)和较小的遗传距离(D=0．256)。然而,在一些酶基因座位如Aep-I(Fst=0．462)和Pgi-I(Fst=0．182),F-统计值相对较大,遗传分化比较明显。     

High population differentiation and genetic variation in the endangered Mexican pine Pinus Rzedowskii (Pinaceae)

Pinus rzedowskii is an endangered pine species from Michoaca´n (central Me´xico), which has been previously reported from only three localities. Classified within the subgenus Strobus, it exhibits intermediate morphological characters between subgenera Strobus and Pinus. We analyzed genetic aspects that could shed light on the evolution and conservation of this species. The genetic structure of nine populations was examined using 14 isozyme loci. Pinus rzedowskii has a relatively high level of genetic variation with 46.8% of the loci assayed being polymorphic, a total of 35 alleles, and a mean heterozygosity per population of 0.219. We calculated Wright's F_ST statistic to estimate gene flow indirectly and to evaluate whether or not there was genetic structuring among populations. We found a marked differentiation among populations (F_ST = 0.175) and significant inbreeding (F_IS = 0.247). No pattern of isolation by distance was found. We also constructed a dendrogram based on a genetic distance matrix to obtain an overview of the possible historical relationships among populations. Finally, we found a convex relationship between the genetic distance among populations and the number of ancestral lineages, suggesting that demographically this species has not been at risk recently. Although endangered, with small and fragmented populations, P. rzedowskii shows higher levels of genetic variation than other conifer species with larger populations or similar conservation status.     

High Polymorphism and Autotetraploid Origin of the Rare Endemic SpeciesOxytropis chankaensisJurtz. (Fabaceae) Inferred from Allozyme Data

Using starch electrophoresis, we examined 19 enzyme systems presumably controlled by 35 loci in the rare endemic tetraploid speciesOxytropis chankaensisJurtz. (Fabaceae). Electrophoretic patterns and their genetic interpretation are presented. The isozyme data suggest tetrasomic inheritance in O. chankaensis. Three or four alleles at a particular locus were found in a number of individual plants, which indicate the autotetraploid origin of this species. Seventeen loci were shown to be polymorphic. As reliable gene markers for population systems, we recommend highly active polymorphic systems showing good allozyme separation (Ce-2, Gpi-2, Gpt-2, Idh-2, Lap, Mdh-2, and Mdh-3). Parameters of allozyme variability proved to be very high for a rare species with a restricted range: P = 48.6%, A = 2, A _p = 3.06, H _ob = 0.173.     

Allozyme variation among Rana balcanica,R. levantina,and R. ridibunda (Amphibia: Anura)1

The allozyme variation among water frogs of the species R. balcanica, R. levantina and R. ridibunda, all formerly considered as one species (R. ridibunda Pallas, 1771), was studied using horizontal starch gel electrophoresis. Blood samples (N # 63) of frogs were collected from five populations in Greece and Israel. Samples (N = 9) of the hybrid frog R. esculenta collected from a locality in Germany were used as an outgroup for phylogenetic analyses. Fifteen enzymes controlled by twenty presumptive loci were identified. Thirteen loci were polymorphic within or among the studied populations. Genetic differentiation among the species was considerably greater than among populations of the same species. Even at Nestos River where R. ridibunda and R. balcanica occur in the same habitats, individuals could be assigned to either species due to characteristic differences of the genotypes (GPI1). This indicates reproductive isolation among these species. The reconstruction of phylogenetic relationships among the three species based on the allozyme data corroborated the model presented on the basis of bioacoustic data: R. ridibunda and R. balcanica (Nei's genetic distance D = 0.0820) are sibling species pertaining to an Eurasian lineage, whereas R. levantina (distance to the European species D = 0.1780 - 0.1955) together with R. perezi represent an independent afroasian lineage.     

THE GENETIC STRUCTURE OF LARGE-LAKE DAPHNIA POPULATIONS

Cyclical parthenogenesis allows study of the genetic and evolutionary characteristics of groups exhibiting both asexual and sexual reproduction. The cladoceran genus Daphnia contains species which vary with respect to the relative incidence of sexual reproduction; pond species tend to undergo sexual reproduction more regularly than species found in large lakes. Previous genetic studies have focused on pond populations, generating expectations about large-lake populations that have not been fully met by recent studies. The present study of the Palearctic species Daphnia galeata further examines the genetic structure of large-lake populations. Nine local populations, from lakes in northern Germany, are examined for genetic variation at seven enzyme loci. Populations exhibit similar allelic arrays and often similar allele frequencies at the five polymorphic loci; values of Nei's genetic distance (D) ranged from 0.002 to 0.239, with a mean of 0.084. F_ST values range from 0.012 to 0.257, and spatial autocorrelation coefficients range from -0.533 to 0.551, for the eight alleles analyzed. With few exceptions, within-population genotypic frequencies were in Hardy-Weinberg equilibrium. There was, however, significant heterogeneity in genotypic frequencies among populations. The number of coexisting clonal groups, as determined by three locus genotypes, is high within populations. Clonal groups are widely distributed among localities. The amount of genetic divergence observed among these large-lake populations is smaller than that previously observed among pond populations and suggests that different processes may be important in determining the genetic structure and subsequent phenotypic divergence of lake versus pond populations.     

中华稻蝗四个种群的遗传分化

采用水平淀粉凝胶电泳技术研究中华稻蝗(Oxya chinensis)四个种群的12个基因座位,探讨其遗传分化.这四个种群分别采自内蒙古呼和浩特、山西代县、山西太原和陕西西安.Ck和Mdh-2在四个种群中均为单态,其余的基因座位至少在一个种群内有两个以上的等位基因;在Ldh和Mdh-1的等位基因频率呈现梯度分布趋势.多态基因座位百分率(P)和平均每个基因座位的等位基因数目(A)分别为58.3%-66.7%和2.2-2.8,平均杂合度为Ho=0.173-0.240.除Gpi,Hk-2,Idh,Ldh和Mdh-1在部分蝗虫种群符合Hardy-Weinberg平衡外,其余绝大多数基因座位的基因型频率显著偏离Hardy-Weinberg平衡.四个种群间FST平均值不存在显著差异(FST=0.0510,P＞0.05),结合高的Nei's遗传一致度(I＞0.97)可知,种群之间遗传分化不明显.我们认为人类的农业活动可能促进了种群间的基因交流,从而降低了分化程度[动物学报50(2)187-192,2004].     

Systematics of Mielichhoferia (Bryaceae: Musci). III. Hybridization between M. elongata and M. mielichhoferiana

Allozyme variation in mixed populations of Mielichhoferia elongata and M. mielichhoferiana was investigated to determine if interspecific hybridization occurs when these two closely related species grow together. Previous research has shown that M. elongata and M. mielichhoferiana can be distinguished by three diagnostic isozyme loci (Gpi-1, Mdh-2, and Mdh-3) at which the two species do not share alleles in 32 allopatric populations from North America and Europe. The present study shows that in five populations from Colorado, Norway, and Sweden, gametophytes resulting from interspecific hybridization can be recognized by recombinant genotypes combining alleles of the otherwise diagnostic loci. A total of 32 multilocus genotypes was found among the 111 individuals sampled, of which 13 were recombinants. The frequency of recombinants ranged from 12% to 35% within populations, and all but one population contained both parental species. Moreover, recombinant genotypes could be accounted for by the allelic constitution of sympatric parents. In two of the populations, more than one hybridization event was necessary to account for the diversity of recombinant genotypes. Twenty-nine of the 32 genotypes detected in this study were restricted to one population each, two occurred in two Swedish populations separated by approximately 14 km, and one occurred in both Sweden and Norway.     

Microsatellite Variation in Two Populations of Free-Ranging Yellow Baboons (Papio hamadryas cynocephalus)

We investigated genetic variation at six microsatellite (simple sequence repeat) loci in yellow baboons (Papio hamadryas cynocephalus) at two localities: the Tana River Primate Reserve in eastern Kenya and Mikumi National Park, central Tanzania. The six loci (D1S158, D2S144, D4S243, D5S1466, D16S508, and D17S804) were all originally cloned from and characterized in the human genome. These microsatellites are polymorphic in both baboon populations, with the average heterozygosity across loci equal to 0.731 in the Tana River sample and 0.787 in the Mikumi sample. The genetic differentiation between the two populations is substantial. Kolmogornov–Smirnov tests indicate that five of the six loci are significantly different in allele frequencies in the two populations. The mean F _ST across loci is 0.069, and Shriver's measure of genetic distance, which was developed for microsatellite loci (Shriver et al., 1995), is 0.255. This genetic distance is larger than corresponding distances among human populations residing in different continents. We conclude that (a) the arrays of alleles present at these six microsatellite loci in two geographically separated populations of yellow baboons are quite similar, but (b) the two populations exhibit significant differences in allele frequencies. This study illustrates the potential value of human microsatellite loci for analyses of population genetic structure in baboons and suggests that this approach will be useful in studies of other Old World monkeys.     

Genetic diversity and morphological differentiation in Liatris helleri (Asteraceae), a threatened plant species

Liatris helleri (Asteraceae) is an insect-pollinated herbaceous perennial endemic to several high-elevation sites in the Blue Ridge Mountains of North Carolina. Allozymes were used to describe the genetic diversity and population structure in nine populations of this rare, federally listed species. Differences in leaf morphology were also examined for greenhouse-grown plants representing several populations. The proportion of the total genetic diversity found among populations, as indicated by the allozyme data, was 16%. Higher levels of population differentiation were found for differences in leaf shape; population of origin accounted for 37% of the variation in maximum leaf width, while families within populations accounted for 7%. In contrast to many endemic species, L. helleri maintains fairly high levels of genetic diversity. For the species, the percent polymorphic loci was 87.5, the average number of alleles at variable loci was 3.00 and the gene diversity was 0.276. Mean population values were percent polymorphic loci =58.4, mean number of alleles per polymorphic locus =2.59 and gene diversity =0.219. The estimated gene flow was low (Nm=0.85–1.32) and a relatively high correlation (r=0.55; p<0.005) was found between linear geographic and genetic distance. This suggests that the populations are partially isolated by distance, despite the limited range (<60 km) of the species. We recommend that population distinetiveness be maintained in restoration efforts.     

草履蚧不同寄主和地理种群遗传分化的RAPD分析

应用随机扩增多态性DNA(RAPD)技术对草履蚧保定、石家庄、邯郸16个不同寄主地理种群遗传多样性和种群分化进行研究,结果显示4个RAPD引物共扩增出41个多态性位点,多态位点比率为100%。遗传距离指数在0.701—0.4360,平均为0.2395。其中以邯郸枫杨和邯郸垂丝海棠为寄主的草履蚧种群遗传距离最小(0.0701);以石家庄紫叶李和邯郸木槿为寄主的种群遗传距离最大(0.4360)。遗传一致度系数在0.6466—0.9290。说明草履蚧不同种群遗传多样性丰富并存在遗传差异。聚类分析结果表明草履蚧种群遗传多样性同时受到寄主和地理因素的双重影响,且不同寄主草履蚧种群已产生明显的遗传分化。