Nine polymorphic microsatellite markers in Crepis sancta (Asteraceae)

We describe nine new variable di‐ and trinucleotide microsatellites in the plant Crepis sancta, as well as conditions for multiplexing and simultaneous genotyping sets of loci. Their variability was assessed in four populations. Four to 33 alleles were detected per locus; two to 23 alleles per population. Significant deviations from Hardy–Weinberg equilibrium could be attributed either to a mating system involving partial selfing or to null alleles. Genetic differentiation over all loci was significant among the four populations studied. These markers will constitute an efficient tool for investigating dispersal patterns in fragmented landscapes. Cross‐species amplification provided few loci variability in three other Crepis species (C. pulcra, C. foetida and C. rubra).     

Population genetic studies of leafhopper (Empoasca) species

Seven populations of the genus Empoasca Walsh 1864 (Homoptera, Typhlocybinae) collected from six different host-plants were electrophoretically analyzed for thirteen enzyme loci. By using both the allozymes and the morphological characters of the male genitalia we found that these populations consisted of only two Empoasca species; E. decedens and E. decipiens. The use of allozymes proved to be the faster and more efficient method for discrimination; nine out of thirteen enzyme loci were diagnostic. E. decedens was found to be the most abundant species in all populations studied. There are no genetic differences between E. decedens populations associated with different host-plants. The total genetic variability was mainly organized within E. decedens populations, explaining more than 95% of the total variability.     

Isolation and characterization of microsatellite markers in the caddisfly Drusus discolor (Trichoptera: Limnephilidae)

We describe the development of and amplification conditions for microsatellite primers isolated from the caddisfly Drusus discolor. Eight polymorphic microsatellite loci were developed and screened for variability using 37 individuals from two populations from central Europe. The primers yielded an average of 8.6 alleles per loci. No linkage disequilibrium between loci was detected, while three loci showed deviations from Hardy–Weinberg equilibrium in one of the two tested populations.     

Microsatellite variation in China’s Hainan Eld’s deer (<Emphasis Type="Italic">Cervus eldi hainanus</Emphasis>) and implications for their conservation

Hainan Eld’s deer (Cervus eldi hainanus) experienced a dramatic decline in the late 1960s through early 1970s and by 1976 only 26 deer remained in Datian of Hainan Island, China. Since then, conservation efforts have successfully rescued this deer from extinction. We employed 10 microsatellite DNA loci to index genetic variation in the one source (Datian) and two introduced populations (Bangxi and Ganshiling) and suggest implications for the conservation of the species. A total of 40 alleles at 10 loci were examined from 198 deer blood samples. The source population harbored all 40 alleles, while the Bangxi and Ganshiling translocated populations contained 24 and 26 alleles, respectively. The genetic variability was low (H _e ≈ 0.33) for each of the three populations. No significant difference in genetic variability between the three populations was detected (P > 0.05); yet significant differentiation was found among the three populations. Our results suggest that founder effects and genetic drift have affected the two translocated populations. For conservation we recommend the three populations be managed as a meta-population. When establishing future reintroductions, the founder population should have a size larger than the original 26 founders in Datian population or be composed of a cohort of over 20 same-age individuals with 1:1 sex ratio. Genetic monitoring for both the source and translocated populations should be continuously conducted in order to assess the effectiveness of deer conservation in the future.     

Isolation of polymorphic microsatellite loci in the ponerine ant Ectatomma tuberculatum

We report the development of 11 microsatellite markers by an enrichment protocol in the ponerine ant Ectatomma tuberculatum. Polymorphism was explored in two colonies collected from Mexico and two colonies from Brazil. From the 11 loci which amplified, seven loci showed intracolonial polymorphism in Mexican colonies and only six loci were variable in populations from Brazil. Observed heterozygosity ranged from 0.18 to 0.84. The other five loci exhibited different alleles between Mexico and Brazil but geographical variability was not investigated further. Cross‐amplification was tested in another species of the same Tribe (Gnamptogenys striatula) and one locus was revealed to be polymorphic.     

Comparative analysis of genetic structure in natural populations of two <Emphasis Type="Italic">Arabidopsis</Emphasis> species with different degree of panmixia

Comparative analysis of genetic structure of northern natural populations of two Arabidopsis species with different degrees of panmixia was performed. The variability of 121 RAPD loci in seven populations of model plant A. thaliana possessing high degree of self fertility was studied together with 93 RAPD loci in population of cross-pollinating species A. lyrata ssp. petraea. The population of A. l. petraea demonstrated higher level of genetic variability (P _99% = 62.50%; H _exp = 0.169) than the populations of A. thaliana, which is obviously connected with biological features of reproduction of the species. A significant level of genetic variability (P _99% = 42.27%; H _exp = 0.126) was revealed in populations of A. thaliana, which is not typical for self-pollinating plant species. The high population polymorphism of A. thaliana in the northern part of its range may be connected with adverse environmental conditions. The genetic distances between populations of the species studied (average D _N = 0.494) confirm close relatedness between A. thaliana and A. l. petraea.     

Genetic variation in the soil phthiracarid mite, Steganacarus (S.) magnus (Nicolet, 1855) (Acarida, Oribatida) (Notulae Oribatologicae XL)

Genetic divergence and variability at 14 enzyme loci were examined in and between Italian populations of two edaphic Oribatid (Acarida, Oribatida) species, Steganacarus (Steganacarus) magnus (8 populations) and S. (S.) hirsutus (1 population). The seven populations belonging to S. (S.) magnus can be divided into two groups according to their phenotype, form anomala (A) (MON, ARG, AST, CDO) and form magna (M) (MAL, MAM, RIF) while another can be considered as hybrid between the two preceding groups (ZOC). Genetic identity (I) values between the S. (S.) magnus populations in spite of their morphological differences ranged from 0.977 to 1.000 showing the great genetic similarity of simple local populations while those of S. (S.) hirsutus indicated two distinct morphological species. The genetic distances between all the populations examined were very low despite the ecological differences and geographical distances between the collecting sites. Genetic variability estimates in all the populations of both species were very low when compared to those reported for most arthropods. Some explanatory considerations are suggested.     

Polymorphisms at two enzyme loci (Sod and Odh) in populations of the Amur sleeper,Perccottus glenii (Pisces,Eleotrididae), from its native range and the colonized area: the effect of introduction on genetic variation

In the first half of the 20th century small founder groups of the Amur sleeper, Perccottus glenii, have been transferred from their native range in the Far East to some regions of the European part of Russia. In order to investigate the consequences of the introductions, 15 Far East populations and 11 European populations, that originated from two transfers, were studied for their variability on two enzyme loci (Sod and Odh) using polyacrylamide gel electrophoresis. For both loci, divergence between populations and heterozygosity in the populations were higher in the colonized regions than in the native range. Heterozygote advantage in small founder populations seems to be a factor resisting genetic drift and determining the changes observed in the genetic structure of the introduced populations.     

GENETIC VARIATION IN ALETES ACAULIS AND ITS RELATIVE,THE NARROW ENDEMIC A. HUMILIS (APIACEAE)

We compared the organization of genetic variability in Aletes humilis, a species restricted to seven populations in north-central Colorado, with A. acaulis, a closely related widespread species. Genetic variability was scored at 11 electrophoretically detectable protein loci. Nine of these loci were polymorphic (i.e., P > 0.95) in both taxa, and were used for interpopulation and interspecific comparisons. Levels of genetic variability and patterns of organization of this variability are very comparable in both species. In contrast to many other narrow endemics, A. humilis is not genetically depauperate when compared to its presumed progenitor. Both biochemical and morphological evidence suggest that A. humilis is derived from A. acaulis; the comparable levels of variability in the two species suggest that A. humilis was derived from a source containing a substantial portion of the original A. acaulis genome, because there is no evidence of a genetic bottleneck or appreciable loss of allelic variability.     

Genetic variation in relation to demography of peripheral pool frog populations (Rana lessonae)

Summary Genetic variation in an isolated northern metapopulation of the pool frog (Rana lessonae) in Sweden was compared to that of Central European populations using enzyme electrophoresis and literature data. Of the 31 loci scored, two (EST-2 andIDH-2) were polymorphic while no variation occurred in seven of the eight loci which are polymorphic in Central European populations.The heterozygosity level of the Swedish pool frogs is very low compared to that of other anuran populations, but their mean proportion of fertilized eggs within egg masses (97.5%) was not lower than in more heterozygous species, and their body size-specific fecundity did not differ from that of Polish conspecifics. The low genetic variability of the Swedish pool frogs is discussed in relation to features of the local populations such as size (N), calculated effective size (N _e ) reproductive success and probable history. It is concluded that long-term strong fluctuations in population size caused by reporductive failure in cold years have contributed more to the low genetic variability than could a single founder event due to a recent introduction by man.     

Microsatellite polymorphism and population subdivision in natural populations of European sea bass Dicentrarchus labrax (Linnaeus, 1758)

Polymorphism of microsatellite markers was used to study the genetic variability and structure in natural populations of European sea bass Dicentrarchus labrax. The data consisted of six microsatellite loci analysed for 172 individuals from three samples collected in the Golfe-du-Lion (France) and one sample collected in the Golfo-de-Valencia (Spain). Our goals were (i) to assess the level of genetic variability as revealed by these markers, (ii) to estimate the genetic differentiation among natural populations within a restricted area, and (iii) to evaluate how microsatellite loci fit the predictions of the two most widely used mutation models (the infinite allele model and the stepwise mutation model). As expected, our results indicate that the genetic polymorphism is very high when compared with previously used genetic markers, the mean expected heterozygosity per locus ranging between 0.69 and 0.93. We also found that all loci but one fitted the infinite allele model better. Using this model as a lower limit, we could extrapolate from the observed diversity effective population sizes on the order of 35 000 individuals. Our results also suggest that there may be a slight genetic differentiation between the two gulfs (F_ST= 0.007, P < 0.05), indicating that the corresponding populations are likely to be dynamically independent. This finding for a species with high dispersal abilities, if confirmed, has important beatings on fish-stock assessment.     

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.     

PERMANENT GENETIC RESOURCES: Isolation of microsatellite loci from the endangered plant Sibara filifolia (Brassicaceae)

Sibara filifolia (Brassicaceae) is a federally endangered annual herb found on two of the California Channel Islands. Previous studies based on allozymes revealed little genetic variability on San Clemente Island. Nine polymorphic microsatellite loci were isolated from individuals on San Clemente Island. We found low levels of allelic variation (mean N_A = 2.3), with seven loci exhibiting significant deviations from Hardy–Weinberg equilibrium (P < 0.01) and 10 pairs of loci exhibiting significant linkage disequilibrium (P < 0.01). Most of the observed variability (mean H_O = 0.003) occurred among populations or in rare homozygous individuals.     

Microsatellite markers for the endangered European mink (Mustela lutreola) and closely related mustelids

The European mink (Mustela lutreola L., 1761) is an endangered carnivore species whose populations suffered a severe decline during the last century. The genotyping of eight polymorphic microsatellite loci revealed a relatively low number of alleles per locus (two to eight), as well as low levels of polymorphism (observed and expected heterozygosity values per locus were 0.49 and 0.54, respectively). Cross‐specific polymerase chain reaction amplifications were successful in seven closely related mustelid species suggesting that these loci may be useful not only for assessing genetic variability in European mink populations but also for determining potential hybridization events between M. lutreola and other mustelid species.     

Genetic structure of three populations of rhesus macaques (Macaca mulatta): Implications for genetic management

One of the prime concerns at zoos and at primate breeding facilities is to maintain genetic variability. This can be accomplished by avoiding inbreeding. It is relatively easy to assess genetic variability and the level of inbreeding by using pedigree information and genetic markers. In this study we used genetic markers controlled by 6 independent polymorphic loci (GPI, PGD, CA2, MPI, DIA1, Tf) to ascertain genetic variation in two captive and one wild population of rhesus monkeys. Two other loci ADA and NP were also examined and found to be monomorphic in the three populations. F-statistics and contingency chi-square analyses indicated that there was significant genetic differentiation among the populations. We also found that the mean heterozygosities were very similar in the three populations, in spite of the diverse breeding strategies. These data are important because rhesus monkeys are frequently used for biomedical research; and the genetic markers provide useful information for genetic management of captive colonies of nonhuman primates. © 1992 Wiley-Liss, Inc.     

Genetic divergence between populations of two closely related troglobitic beetle species (Speonomus: Bathysciinae,Coleoptera)

Genetic variability and divergence at 13 enzyme loci were studied in two species of troglobitic beetles (Speonomus zophosinus andhydrophilus 12 populations) collected from the Pyrenees mountains. These allopatric species exhibit a high degree of specialization to underground life and a very small geographical range. Four diagnostic loci arePgi, Est-2, Pac-1, Phi. Within each species polymorphic loci exhibited marked spatial variation of allele frequencies, sometimes over short distances (5–10 km). The levels of genetic variability are comparable to those observed in non-cave invertebrates (frequency of polymorphic loci: 0.31; average expected heterozygosity: 0.112±0.015). Moreover, a single species showed variability in the average level of heterozygosity (0.06 to 0.172). Patterns of genetic differentiation among species were also studied; mean genetic distance (D: 0.263±0.010) between the twoSpeonomus species was of the same order of magnitude as most data reported in the literature between species. A significant heterozygote deficiency occurs in local populations and for all loci. This deficit does not vary from locus to locus. Several hypotheses were examined in an attempt to account for these observations in connection with the species biology. This deficit probably is due to the breeding structure of the population (inbreeding and assortative mating) coupled with limited dispersal ability.     

Structure and genetic variability of golden mussel (Limnoperna fortunei) populations from Brazilian reservoirs

The golden mussel, Limnoperna fortunei a highly invasive species in Brazil, has generated productive, economical, and biological impacts. To evaluate genetic structure and variability of L. fortunei populations present in fish farms in the reservoirs of Canoas I (CANFF), Rosana (ROSFF), and Capivara (CAPFF) (Paranapanema River, Paraná, Brazil), eight microsatellite loci were amplified. Five of those eight loci resulted in 38 alleles. The observed heterozygosity (Ho) was lower than the expected heterozygosity (He) in all populations, with a deviation from the Hardy–Weinberg equilibrium (HWE). The average value for the inbreeding coefficient (Fis) was positive and significative for all populations. There was higher genetic variability within populations than among them. The fixation index (Fst) showed a small genetic variability among these populations. The occurrence of gene flow was identified in all populations, along with the lack of a recent bottleneck effect. The clustering analysis yielded K = 2, with genetic similarity between the three populations. The results demonstrate low genetic structure and suggest a founding population with greater genetic variability (ROSFF). Our data point to the possible dispersal of L. fortunei aided by anthropic factors in the upstream direction. It was concluded that the three populations presented a unique genetic pool for Paranapanema River, with occurrence of gene flow.     

Microsatellite primers for the Atlantic coastal killifish,Fundulus heteroclitus,with applicability to related Fundulus species

The mummichog (Fundulus heteroclitus), a common Atlantic coastal killifish, is a model vertebrate species for the study of molecular genetic variation in natural populations and of environmental toxicology. We report the development of a set of 20 microsatellite loci in this species. Average expected heterozygosity across all loci was 0.84 (range: 0.60–0.97), revealing a high level of variability at most loci. A survey of seven additional Fundulus species yielded one or two robust amplification products in over half (63%) of the species–primer combinations tested. Therefore, many of these loci will also prove useful in studies of other members of the genus Fundulus.     

Allozyme polymorphisms within and among open-pollinated and adapted exotic populations of maize

Summary Twelve U.S. Corn Belt open-pollinated and five adapted exotic populations of maize (Zea mays L.) were assayed for allozyme (allele) variation at 13 enzyme marker loci. Extensive allozyme variability was observed in all populations studied. No locus was monomorphic over all populations. Each of the lociIdh2, Got1, Mdh2, Pgd1, andPgd2 expressed two allozymes over all populations,Adh1, Acp1, Prx1, andEst1 each had three allozymes present,Est4, Glu1, andEnp1 had five allozymes, andAcp4 had six allozymes present. Significant deviations of genotypic frequencies were detected from Hardy-Weinberg equilibrium frequencies and 94% of average Fixation Index values indicated heterozygote deficiencies, which suggested that nonrandom mating and/or natural selection favoring homozygotes were possible factors affecting the maintenance or loss of genetic variability marked by these enzyme loci. Genetic distance and cluster analyses indicated that the observed genetic variability at the 13 enzyme loci was closely related to Dent and Flint types of maize.     

Microsatellite markers isolated from barn swallows (Hirundo rustica)

Fifteen polymorphic microsatellite DNA loci were isolated from barn swallow (Hirundo rustica) and optimized for future studies of radiation‐induced mutations in populations from Ukraine. The loci were screened for variability among 25 individuals from two populations. The primers amplified loci with relatively high numbers of alleles ranging from five to 32 alleles per locus and polymorphic information content from 0.481 to 0.951. Observed heterozygosity varied from 0.458 to 0.960. None of the loci showed deviations from Hardy–Weinberg equilibrium in either population.