Low allozyme variability in Bactrocera albistrigata (Insecta: Diptera: Tephritidae) from Peninsular Malaysia

1. Population samples of Bactrocera albistrigata from Peninsular Malaysia were analyzed for 12 to 14 gene-enzyme systems comprising 15-18 loci. 2. Three loci, aMDH, PGD and PGM, were polymorphic. 3. Anodal malate dehydrogenase and phosphogluconate dehydrogenase were represented by two alleles each, while phosphoglucomutase was represented by three alleles. 4. Phosphoglucomutase had a higher heterozygosity than anodal malate dehydrogenase and phosphogluconate dehydrogenase. 5. B. albistrigata was characterized by low genetic variability, as measured by the proportion of polymorphic loci and heterozygosity.     

Evaluation of genetic variability of the Kamchatka crab Paralithodes camtschaticus (Tilesius) using allozyme markers

Interspecific genetic variation in populations of red king crab Paralithodes camtschaticus Tilesius (Litholidae, Decapoda: Crustacea) was examined using allozyme markers. The activity of 57 enzymes and the general protein presumably encoded by 92 loci was detected. The level of allozyme variability was low: the expected heterozygosity and the proportion of polymorphic loci were respectively 0.027 +/- 0.008 and 6.5%. This level of heterozygosity is three times lower than the average value for 122 crustacean species (0.082 +/- 0.007). Although genetic variants were found at 22 loci, their frequencies were generally low: only in loci 6-Pgd, Alp-1, and Pep-1 did the frequencies of the most common alleles not exceed 0.9. All polymorphic loci except one had two alleles; the exception was 6-Pgd, which had three alleles. The possible reasons for the low level of allozyme variability in red king crab are discussed.     

Characterization of polymorphic microsatellite DNA markers in the black-tailed godwit (Limosa limosa: Aves)

We isolated and tested 16 microsatellite loci in black-tailed godwits from the Netherlands (Limosa limosa limosa), and from Australasia (subspecies melanuroides). One locus was monomorphic, two loci had null-alleles and one was significantly heterozygote deficient. The remaining 12 polymorphic loci had on average 7.9 alleles (range 5-11) and the mean expected heterozygosity was 0.69. No significant linkage disequilibrium between the loci was observed and all loci were autosomal. Fourteen loci were successfully cross-amplified in bar-tailed godwit (Limosa lapponica).     

Inheritance of allozyme variants in bishop pine (Pinus muricuta D. Don)

Isozyme phenotypes are described for 45 structural loci and 1 modifier locus in bishop pine (Pinus muricata D. Don,) and segregation data are presented for a subset of 31 polymorphic loci from 19 enzyme systems. All polymorphic loci had alleles that segregated within single-locus Mendelian expectations, although one pair of alleles at each of three loci showed significant segregation distortion. The consistency of resolution and segregation at many loci in bishop pine makes electrophoretic analyses feasible for many purposes in this species.     

Polymorphism of microsatellite loci of European chickpea cultivars

Polymorphism of 13 microsatellite loci in 61 chickpea varieties was studied. The 47 alleles were detected. Three loci were monomorphic, the other ones showed polymorphism. Genetic diversity of chickpea varieties in all loci was 0,41 according to Nei polymorphism index (D). It was concluded that chickpea varieties from Europe had insignificant microsatellite loci diversity. The most polymorphic group was chickpea varieties from Russia (D = 0,38), the least polymorphic - Spanish varieties (D = 0,25). Consensus tree representing the most credible divergence of Europe chickpea varieties was constructed. The possible causes of clustering chickpea varieties in a common cluster are discussed.     

Development and characterization of simple sequence repeat (SSR) markers and their use in determining relationships among Lycopersicon esculentum cultivars

The simple sequence repeat (SSR) or microsatellite marker is currently the preferred molecular marker due to its highly desirable properties. The aim of this study was to develop and characterize more SSR markers because the number of SSR markers currently available in tomato is very limited. Five hundred DNA sequences of tomato were searched for SSRs and analyzed for the design of PCR primers. Of the 158 pairs of SSR primers screened against a set of 19 diverse tomato cultivars, 129 pairs produced the expected DNA fragments in their PCR products, and 65 of them were polymorphic with the polymorphism information content (PIC) ranging from 0.09 to 0.67. Among the polymorphic loci, 2-6 SSR alleles were detected for each locus with an average of 2.7 alleles per locus; 49.2% of these loci had two alleles and 33.8% had three alleles. The vast majority (93.8%) of the microsatellite loci contained di- or tri-nucleotide repeats and only 6.2% had tetra- and penta-nucleotide repeats. It was also found that TA/AT was the most frequent type of repeat, and the polymorphism information content (PIC) was positively correlated with the number of repeats. The set of 19 tomato cultivars were clustered based on the banding patterns generated by the 65 polymorphic SSR loci. Since the markers developed in this study are primarily from expressed sequences, they can be used not only for molecular mapping, cultivar identification and marker-assisted selection, but for identifying gene-trait relations in tomato.     

Fifteen polymorphic microsatellite markers for the giant spiny frog, Paa spinosa

We characterized 15 polymorphic microsatellite loci for the giant spiny frog, Paa spinosa. These loci were highly polymorphic when screened in 38 individuals from two different populations, with nine to 23 alleles per locus. The range of observed and expected heterozygosities was 0.231-0.916 and 0.296-0.944, respectively. These polymorphic loci will be useful for assessing genetic diversity, population structure, gene flow, population assignment and determining paternity in the giant spiny frog.     

Isolation and characterization of microsatellites in yellow perch (Perca flavescens)

A total of 45 microsatellite loci from yellow perch, Perca flavescens, were isolated and characterized. Among the 45 microsatellite loci, 32 had more than two alleles. A wild population of P. flavescens (n = 48) was used to examine the allele range of the microsatellite loci. Mendelian inheritance of alleles was confirmed by examining the amplified products in pair‐mated families. The number of alleles for the 32 polymorphic loci varied from two to 16, and observed heterozygosity ranged between 0.024 (YP79) and 0.979 (YP60). Cross‐species polymorphic amplification in four other Percidae species was successful for 22 loci.     

Analysis of isozyme loci in the face fly,Musca autumnalis DeGeer

Vertical polyacrylamide gel electrophoresis was used to resolve enzymes at 50 putative loci in Iowa face flies, a recently arrived, colonizing, Palearctic species. Sixty-two percent of the 50 loci were polymorphic. The mean number of alleles per polymorphic locus was 3.2 +/- 1.38; the mean among all loci was 2.38 +/- 1.62 alleles. The effective number of alleles among 50 loci was 1.4 +/- 0.62. Mean observed and expected heterozygosities for the 50 face fly loci were 0.167 +/- 0.037 and 0.186 +/- 0.031, respectively. Comparison of the electrophoretic data for Musca autumnalis and for M. domestica L. showed similar high levels of gene diversity. A survey of gene diversity at 12 loci among six geographically independent laboratory colonies demonstrated statistically significant genetic differentiation that was probably due to drift after colonization.     

Isolation and characterization of polymorphic tetranucleotide microsatellite loci in the pelagic perciform fish Pomatomus saltatrix (Linnaeus, 1766) from South Africa

Eight polymorphic microsatellite loci, containing simple tetranucleotide repeats, were isolated de novo from a Pomatomus saltatrix partial genomic library using the fast isolation by amplified fragment length polymorphism of sequences containing repeats protocol. These loci were further characterized in 100 individuals from two putative populations off the South African east coast. The loci are highly polymorphic with 18-37 alleles (on average 24 alleles/locus) and the observed heterozygosity in both populations was high (0.79). These loci will be used to assess population structuring in P. saltatrix along the southern African coast with consideration of implications for future management of this important linefish species.     

奶牛微卫星基因座与产奶性能关系的研究

根据小鼠与牛的遗传比较图谱及相关报道选择了与weaver基因连锁的7个微卫星基因库,并在荷斯坦牛群体中对这些基因座进行群体遗传学特性分析。选择具有中度以上多态性的4个微卫星基因座（BM6438、BMS2321、BMS711和TGLA116）进行产奶性能的相关分析。最小二乘分析结果表明,4个微卫星基因座对产奶量影响不显著（P＞0．05）,BM6438生BMS711基因座对乳成分影响不显著（P＞0．05）,BMS2321基因座对乳蛋白量和乳蛋白率有极显著的影响（P＜0．01）,TGLA116对乳蛋白量和乳蛋白率的影响达到0．05的显著水平。     

Highly polymorphic tetranucleotide microsatellite loci for the eastern Canary Island lizard,Gallotia atlantica

We describe 10 polymorphic tetranucleotide microsatellite loci from the eastern Canary Island lacertid lizard, Gallotia atlantica. Loci were isolated from a partial genomic library that had been enriched for AAAG repeat sequence. All loci were highly polymorphic (eight alleles or more) with observed heterozygosities from 0.75 to 1.00. At least four loci were successfully amplified and polymorphic in the Gran Canarian lacertid, Gallotia stehlini. These loci will be used to examine correlations between patterns of gene flow and recent volcanism on the island of Lanzarote.     

PERMANENT GENETIC RESOURCES: Ten polymorphic microsatellite markers for the pygmy rabbit (Brachylagus idahoensis)

We developed 10 polymorphic microsatellite loci for the pygmy rabbit (Brachylagus idahoensis). Nine of the 10 loci amplified reliably and had a low frequency of null alleles. Number of alleles per locus ranged from four to 12, and observed and expected heterozygosities ranged from 0.26 to 0.89 and from 0.63 to 0.88, respectively. These loci will be useful in determining population genetic structure and assessing patterns of gene flow in the pygmy rabbit.     

Microsatellite loci in the Japanese subterranean termite,Reticulitermes speratus

Reticulitermes termites have such a cryptic life style and complex colony structure that polymorphic microsatellite markers are desired to investigate their population and colony structures. We successfully isolated seven microsatellite loci in R. speratus , the Japanese subterranean termite, five of which were polymorphic. These polymorphic loci had 2–8 alleles per locus and their observed heterozygosities ranged from 0.059 to 0.438. These five loci were also polymorphic in R . kanmonensis , distributed sympatrically with R. speratus in the Kanmon Region, western Japan; the number of alleles per locus was 2–5, and observed heterozygosity was 0.176–0.625.     

Five new microsatellite loci for Oliver flounder (Paralichthys olivaceus) from an expressed sequence tag (EST) library and cross‐species amplification

Five microsatellite loci have been isolated and characterized from a cDNA library of Oliver flounder, Paralichthys olivaceus. All loci were found to be polymorphic and had between four and 10 alleles. Observed and expected heterozygosities varied from 0.70 to 0.90 and from 0.52 to 0.80, respectively. Five additional fish species assessed for cross‐species amplification revealed between zero and three positive amplifications and between zero and two polymorphic loci per species.     

Isolation and characterization of polymorphic microsatellite loci from RAPD product in half-smooth tongue sole (Cynoglossus semilaevis) and a test of cross-species amplification

Eleven polymorphic microsatellite loci have been isolated and characterized from random amplified polymorphic DNA product in half-smooth tongue sole, Cynoglossus semilaevis. Twenty-one microsatellites were selected for designing microsatellite primers, of which 11 gave working primer pairs. They had between three and 12 alleles. Observed and expected heterozygosities varied from 0.53 to 0.93, and from 0.52 to 0.80, respectively. Five additional fish species assessed for cross-species amplification revealed between one and three positive amplifications and between zero and three polymorphic loci per species.     

Characterization of microsatellite loci isolated in midget faded rattlesnake (Crotalus viridis concolor)

Primers for five polymorphic microsatellite loci were developed for the midget faded rattlesnake (Crotalus viridis concolor), a rare subspecies of western rattlesnake (Crotalus viridus) found only in parts of Wyoming, Colorado, and Utah. Five polymorphic microsatellites were isolated, four of which had relatively high levels of diversity (eight to nine alleles). We found only two departures from Hardy–Weinberg equilibrium and they occurred in different loci, so null alleles are likely not a problem. Moreover, we found that no two loci were linked. These loci will be applicable for population genetic analysis and perhaps analysis of paternity and mating systems.     

Limited usefulness of microsatellite markers from the malaria vector Anopheles gambiae when applied to the closely related species Anopheles melas

Anopheles melas is a brackish water mosquito found in coastal West Africa where it is a dominant malaria vector locally. In order to facilitate genetic studies of this species, 45 microsatellite loci originally developed for Anopheles gambiae were sequenced in An. melas. Those that were suitable based on repeat number and flanking regions were examined in 2 natural populations from Equatorial Guinea. Only 15 loci were eventually deemed suitable as polymorphic markers in An. melas populations. These loci were screened in 4 populations from a wider geographic range. Heterozygosity estimates ranged from 0.18 to 0.79, and 2.5-15 average alleles were observed per locus, yielding 13 highly polymorphic markers and 2 loci with lower variability. To examine the usefulness of microsatellite markers when applied in a sibling species, the original An. gambiae specific markers were used to amplify 5 loci in An. melas. Null alleles were found for 1 An. gambiae marker. We discuss the pitfalls of using microsatellite loci across closely related species and conclude that in addition to the problem of null alleles associated with this practice, many loci may prove to be of very limited use as polymorphic markers even when used in a sibling species.     

Development of microsatellite markers in white birch (Betula platyphylla var. japonica)

Betula platyphylla var. japonica is a typical pioneer tree species in the secondary succession in northern Japan. We describe the cloning and characterization of 13 polymorphic, codominant microsatellite loci isolated from this species. These polymorphic loci had 2–8 alleles per locus and a range of expected heterozygosities from 0.050 to 0.808.     

Population structure of Atlantic salmon (Salmo salar L.): a range-wide perspective from microsatellite DNA variation

Atlantic salmon (n = 1682) from 27 anadromous river populations and two nonanadromous strains ranging from south-central Maine, USA to northern Spain were genotyped at 12 microsatellite DNA loci. This suite of moderate to highly polymorphic loci revealed 266 alleles (5-37/locus) range-wide. Statistically significant allelic and genotypic heterogeneity was observed across loci between all but one pairwise comparison. Significant isolation by distance was found within and between North American and European populations, indicating reduced gene flow at all geographical scales examined. North American Atlantic salmon populations had fewer alleles, fewer unique alleles (though at a higher frequency) and a shallower phylogenetic structure than European Atlantic salmon populations. We believe these characteristics result from the differing glacial histories of the two continents, as the North American range of Atlantic salmon was glaciated more recently and more uniformly than the European range. Genotypic assignment tests based on maximum-likelihood provided 100% correct classification to continent of origin and averaged nearly 83% correct classification to province of origin across continents. This multilocus method, which may be enhanced with additional polymorphic loci, provides fishery managers the highest degree of correct assignment to management unit of any technique currently available.