Nucleotide sequences of the microsatellite locus <Emphasis Type="Italic">Du215 (arm)</Emphasis> allelic variants in the parthenospecies <Emphasis Type="Italic">Darevskia armeniaca</Emphasis> (Lacertidae)

Using monolocus PCR analysis with the pairs of primers designed for the Du215 locus of Darevskia unisexualis, allelic polymorphism at the orthologous locus in the populations of the related parthenospecies D. armeniaca was investigated. It was demonstrated that Du215 (arm) locus was polymorphic and in the populations of parthenospecies D. armeniaca (n = 127) represented by at least three allelic variants, differing from each other by the size and composition of microsatellite cluster, and by single nucleotide substitutions in flanking DNA. Unlike the Du215 locus, Du215 (arm) was shown contain not only GATA, but also (GACA) repeats, which were absent in D. unisexualis. Thus, in this study, the data on the molecular nature of allelic polymorphism at one of the microsatellite loci of the parthenospecies D. armeniaca were reported.     

Molecular structure of allelic variants of microsatellite loci <Emphasis Type="Italic">Du281</Emphasis> and <Emphasis Type="Italic">Du47</Emphasis> in unisexual and bisexual lizard species of the genus <Emphasis Type="Italic">Darevskia</Emphasis>

Experimental data on the molecular structure and variability of microsatellite loci in unisexual and bisexual lizard species of the genus Darevskia were analyzed. The allelic variants of Du281 and Du47 were found to differ in the number of monomers, the structure of microsatellite clusters, and point mutations in these clusters and flanking DNA. Interspecific comparison of alleles of these loci revealed both variable regions in the microsatellite clusters and allele-specific evolutionarily conserved nucleotide groups. In general, the results of comparative structural analysis of allelic variants testify to a high genetic similarity of the unisexual and bisexual lizard species studied and reveals the characteristic features of their interspecies variability.     

Nucleotide polymorphisms of candidate genes of adaptive significance in the ural populations of <Emphasis Type="Italic">Larix sibirica</Emphasis> Ledeb.

The objectives of conservation and sustainable forest management require in depth study of genomes of woody plants and definition of their intraspecific genetic diversity. In recent years, an approach was developed based on the study of “candidate genes” that can potentially be involved in the formation of adaptive traits. In this study, we investigated nucleotide polymorphism of several adaptive candidate genes in the populations of Siberian larch (Larix sibirica Ledeb.) in the Urals. Representatives of this genus are among the most valuable and widely distributed forest tree species in Russia. From ten selected gene loci in the genome of L. sibirica, we isolated and investigated three loci, one of which (ABA-WDS) was sequenced in L. sibirica for the first time. The total length of the analyzed sequence in each individual amounted to 2865 bp. The length of locus alignment was from 360 bp to 1395 bp. In total, we identified 200 polymorphic positions. The most conservative is locus 4CL1-363, and the most polymorphic is locus sSPcDFD040B03103-274. The studied populations of L. sibirica are characterized by a high level of nucleotide polymorphism in comparison with other species and genuses (Picea, Pinus, Pseudotsuga, Abies) conifers plants (Hd = 0.896; π = 0.007; θ_W = 0.015). The most selectively neutral polymorphism (D _T =–0.997) was attributed to locus 4CL1-363, and polymorphism with high probability of adaptability (D _T =–1.807) was determined for the ABA-WDS locus. We identified 54 SNP markers, only five of which were nonsynonymous (9.26%) replacements. The average frequency of SNPs in the three studied loci of L. sibirica was one SNP in 53 bp. We detected unique SNP markers for eight populations, which could potentially be used to identify populations. Populations that are characterized by the highest number of unique SNP markers can be recommended for selection in order to preserve the gene pool of the species.     

Genetic differentiation among natural populations of the lizard complex <Emphasis Type="Italic">Darevskia raddei</Emphasis> as inferred from genome microsatellite marking

The article presents the genetic parameters of the populations of lizards of the Darevskia raddei complex (D. raddei nairensis and D. raddei raddei) and the populations of D. valentini calculated on the basis of the analysis of variability of 50 allelic variants of the three nuclear genome microsatellite-containing loci of 83 individuals. It was demonstrated that the F_st genetic distances between the populations of D. raddei nairensis and D. raddei raddei were not statistically significantly different from the F_st genetic distances between the populations of different species, D. raddei and D. valentini. At the same time, these distances were statistically significantly higher than the F_st distances between the populations belonging to one species within the genus Darevskia. These data suggest deep divergence between the populations of D. raddei raddei and D. raddei nairensis of the D. raddei complex and there arises the question on considering them as separate species.     

Genetic structure of populations and natural hybridization between <Emphasis Type="Italic">Dactylorhiza salina</Emphasis> and <Emphasis Type="Italic">D. incarnata</Emphasis> (Orchidaceae)

The results of studying the polymorphism and genetic structure of populations of D. salina and D. incarnata growing in Zabaykalsky krai and Buryatia are represented according to the data of allozyme analysis of eight genetic loci (PGI, NADHD, SKDH, GDH, PGM, DIA, ADH, and IDH). The specificity of the allelic structure of loci SKDH, PGM, and IDH is established, for which D. salina and D. incarnata reliably differ from each other. It is shown that interspecies introgressive hybrid complexes with different genetic structures were formed in Transbaikalia. Places of mass growth of D. incarnata were observed to have single plants of D. salina, the interspecies hybrids of the first and subsequent generations. Places of mass growth of D. salina were observed to contain only the hybrids that are not hybrids of the first generation. They were heterozygous not for three loci with differentiating alleles of both parents, SKDH, PGM, and IDH, but for only one of them. The degree of genetic differentiation among five populations of D. salina was on average 7.5% and that of D. incarnata was 7.1%, which in accordance with Wright’s estimation relates to mean values. The average value of FST for all studied populations of the two related species of the genus Dactylorhiza was 0.478, indicating a very high degree of genetic differentiation between D. salina and D. incarnata growing in Transbaikalia. The greatest differences between the species are for the allelic structure of loci SKDH, PGM, and IDH (FST was equal to 0.705, 0.976, and 0.762, respectively). Analysis of molecular variance (AMOVA) showed that populations of D. salina and D. incarnata in the zone where their ranges in Zabaykalsky krai and Buryatya overlap have essential differences both for the variation of alleles frequencies of eight loci (71%, d.f. = 9) and for the variability of genotypes (61%, d.f. = 9). Despite the fact that D. salina and D. incarnata explicitly share a gene flow as a result of interspecies hybridization, the genetic differentiation of populations of these related species remains at a high level.     

Genetic structure of the populations of <Emphasis Type="Italic">Dactylorhiza ochroleuca</Emphasis> and <Emphasis Type="Italic">D. incarnata</Emphasis> (Orchidaceae) in the area of their joint growth in Russia and Belarus

We carried out an allozyme analysis to investigate polymorphism and genetic structure of the populations of D. incarnata and D. ochroleuca in regions of their joint growth in Russia and Belarus. We found that D. ochroleuca individuals in the populations of the Urals and Siberia, which are distant fragments from the main range of the species, do not differ significantly from individuals within the main part of the area (Belarus) on the basis of the allelic composition of eight gene loci. We revealed that D. ochroleuca and D. incarnata are differentiated by different alleles of the GDH locus. Thus, we established a genetic marker suitable to distinguish these closely related taxa. In addition to the GDH locus, D. ochroleuca and D. incarnata in the places of their joint growth, differ in the allelic structure of the PGI and NADHD loci. D. incarnata from the Urals and Siberia were polymorphic for both loci, and individuals from Belarus were polymorphic for one locus (PGI). In contrast, all D. ochroleuca individuals growing in sympatric populations with polymorphic D. incarnata were homozygous for the same alleles. Thus, comparison of the genetic structure of D. ochroleuca and D. incarnata points to the existence of a genetic isolation and a functioning isolation mechanism even under conditions of their joint growth. We found that the GDH locus in D. incarnata is polymorphic only in populations which grow together with D. ochroleuca, with exception a few examples. Thus, we conclude that variability of the GDH locus in D. incarnata is associated with hybridization with D. ochroleuca.     

Molecular genetic characteristic of dinucleotide microsatellite loci in parthenogenetic lizards <Emphasis Type="Italic">Darevskia unisexualis</Emphasis>

In the present study, the first molecular genetic investigation of dinucleotide (GT) _n microsatellite loci in parthenogenetic lizards Darevskia unisexualis was performed. New polymorphic locus, Du214, (GenBank Ac. No. EU252542) was identified and characterized in detail. It was demonstrated that allele of this locus differed in the size and structure of microsatellite locus, as well as in point mutations, the combinations of which enabled the isolation of stabile fixed double nucleotide substitutions A-A (alleles 2 and 4) and G-T (alleles 1, 3, 5, and 6). Double nucleotide substitutions described were also identified in the orthlogous loci of the parental species genomes, D. raddei (G-T) and D. valentine (A-A). Based on the analysis of allele distribution pattern at this locus in all populations of parthenospecies D. unisexualis, mathematic model was elaborated and realized. Using this model, frequencies of allelic variants for all populations of the species of interest were calculated and population genetic structure of D. unisexualis was characterized. Genetic contribution of each population to the species gene pool was determined. The data obtained demonstrated that microsatellite variation was one of the factors of clonal and genetic diversity of a parthenospecies.     

Genetic structure of the Russian populations of <Emphasis Type="Italic">Pyrenophora tritici-repentis</Emphasis>, determined by using microsatellite markers

The population genetic structure of plant pathogenic fungus Pyrenophora tritici-repentis was examined using microsatellite (SSR) markers. According to the geographical origin of the pathogen populations, they were designated as North Caucasian (S, 33 isolates), northwest (Nw, 39), and Omsk (Om, 43). The populations were analyzed at the nine most polymorphic SSR loci, at which 75 alleles were identified. To characterize the genetic variation within and between populations, the AMOVA algorithm as implemented in the Arlequin v. 3.5 software program was used. The number of alleles per locus ranged from 5 to 12 and their sizes varied within the range from 180 to 400 bp. The mean gene diversity at SSR loci was high for all populations (H = 0.58–0.75). The populations were considerably different in the frequencies of individual alleles of the SSR loci. Most isolates in the populations were represented by unique haplotypes. The within-population variation of the isolates at molecular markers was 86.4%; among the populations, 13.6%. Substantial interpopulation differences were found between the Om and S (F_st = 0.16) and between the Om and Nw (F_st = 0.20) populations, whereas between the S and Nw populations, these differences were small (F_st = 0.05). Thus, it was demonstrated that the population of P. tritici-repentis from Omsk oblast had the independent status of the geographical population; northwest and North Caucasian populations differed in the allelic diversity of SSR loci, and despite the low F_st value (0.05), they also belonged to independent geographical populations.     

Comparison of Alleles at <Emphasis Type="Italic">Gli-2</Emphasis> Loci of Common Wheat by Means of Two-Dimensional Electrophoresis of Gliadin

Electrophoretic mobility (EM) and molecular weight (MW) of some allelic variants of α- and β-gliadins contrlled by Gli-2 loci were compared by means of two-dimensional (APAGE × SDS) electrophoresis. Comparison of α-gliadins of the alleles Gli-A2b and Gli-A2p, of β-gliadins of the Gli-B2b and Gli-B2c, and of β-gliadins of the Gli-D2b, Gli-D2c, Gli-D2j, and Gli-D2r indicated that a gliadin with lower EM had, as a rule, bigger MW which is known to depend on the length of the polyglutamine domain of gliadin of α-type. However, allelic variants of the α-gliadin encoded by Gli-D2b and Gli-D2e differ in EM but not in apparent MW. It might be caused by a substitution of some charged/uncharged aminoacids in the polypeptide of gliadin. Allele Gli-B2o which is very frequent in up-to-date common wheat germplasm originated probably by means of unequal crossingover. Some alleles at Gli-A2 is found to control completely different blocks of gliadins and therefore might come to common wheat from different genotypes of the polymorphic diploid donor of the A genome. The results indicate that the reason of the known more vast polymorphism of gliadins controlled by Gli-2 loci as compared with Gli-1 loci is the considerable difference of the structure, first, of Gli-1 and Gli-2 loci (Gli-2 loci have more expressed genes per locus) and, second, of genes encoding gliadins of α- and γ-types (α-gliadins are shown to contain a long polyglutamine sequences highly variable in their length).     

Genetic differentiation of <Emphasis Type="Italic">Puccinia triticina</Emphasis> Erikss. in Russia

A collection of Puccinia triticina isolates was characterized for polymorphism of microsatellite loci and estimated for their differentiation by geographic origin. The collection included 20 isolates from the Ural region, 31 from West Siberia, 53 from Central Europe, 32 from the Northwest region, 32 from the Volga region, and 40 from the North Caucasus (24 from Dagestan and 16 from Krasnodar and Stavropol). The studied isolates were represented by 65 virulence phenotypes. In the polymorphism analysis of 18 microsatellite loci, 69 genotypes were determined. The index values of genetic distances (F _st, R _st, KB _c) between populations for microsatellite loci indicated differentiation of P. triticina isolates according to geographical origin, and they were clustered into three groups: (1) Asian, (2) European, and (3) North Caucasian. The North Caucasian isolates from Krasnodar and Stavropol regions were closer in similarity to European isolates than the Dagestan ones. Current analysis confirmed the assumption made earlier on the basis of the virulence analysis about the existence of several geographic fungi populations in Russia.     

Polymorphism of pigmentation genes (<Emphasis Type="Italic">OCA2</Emphasis> and <Emphasis Type="Italic">ASIP</Emphasis>) in some populations of Russia

In Russian populations, polymorphism of two pigmentation system genes, OCA2 (loci 305, 355, and 419, tested in Russians, Buryats, Chukchi, Koryaks, and Evens) and ASIP (locus 8818, tested in Russians and Buryats) was examined. Pairwise comparisons of the F _ST distances between the populations showed that only the populations from Northeast Asia (Chukchi, Koryaks, and Evens) were statistically significantly different from all other populations, at least relative to one of the OCA2 locus. In Russians from Pskov oblast and Novgorod oblast, increased frequency (up to 6%) of the OCA2 allele 419A was revealed. In earlier studies, as association of this allele with green eye color was demonstrated. The data obtained in terms of their application for ethnic population genetics.     

Study of Genetic Diversity of Earthworm <Emphasis Type="Italic">Lumbricus rubellus</Emphasis> Hoff. (Oligochaeta,Lumbricidae)

A polymorphism of the total protein (MY) and nonspecific esterase (EST) patterns was revealed in the musculocutaneous sac of earthworm Lumbricus rubellus by polyacrylamide gel electrophoresis. The revealed polymorphism is attributed to genetically determined codominant systems, each of which is controlled by the corresponding locus, My and Est, represented by two and four alleles, respectively. The allelic frequency distribution of both loci demonstrated genetic heterogeneity of four L. rubellus samples from Moscow and Moscow Region (311 individuals in total). Allelic frequencies of the revealed loci are proposed as genetic markers for monitoring L. rubellus generations in vermiculture.     

Gene pool state and degree of infestation by bark beetle (<Emphasis Type="Italic">Ips tipographus</Emphasis> L.) of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> L. Karst.) natural populations and planted stands in Moscow region

A comparative analysis of the gene pool state in natural populations and planted stands of Norway spruce and the degree of their infestation by the bark beetle in the Moscow region was conducted taking into account the dynamic state of communities (4 populations, 148 samples, 24 isoenzyme loci). The degree of infestation by the bark beetle of conditionally native communities is 0%; for planted stands, it is 90–100%; and for a short-term community, it is 15–20%. The comparison of “healthy” populations and those infested with bark beetle by average values of observed heterozygosity (H _O) detected no significant differences. However, the test on allelic frequency heterogeneity demonstrated the difference of planted stands from conditionally native populations both by three loci (Fe-2, Idh-1, Mdh-3) and by the totality of 18 polymorphic isoenzyme loci; the short-term population differs from conditionally native population only by two loci. The value of the inbreeding coefficient by the Idh-1 locus is significantly higher in both populations infested with the bark beetle than in “healthy” populations. The results of conducted studies demonstrate the necessity of continuation of the study on the gene pool state in Norway spruce populations owing to the degree of their infestation by the bark beetle along with the study on the dynamic state of the communities; this can provide a key to solving the problem of the forest preservation from pests.     

Genetic structure and differentiation of populations of the tetraploid species <Emphasis Type="Italic">Oxytropis chankaensis</Emphasis> (Fabaceae)

The population genetic variation of the tetraploid species Oxytropis chankaensis Jurtz. (Fabaceae), a local endemic of the western coast of Khanka Lake (Primorye), was examined. Five populations were analyzed using 28 isozyme loci encoding 16 enzyme systems. Significant allelic heterogeneity among the populations was found for six out of twelve polymorphic loci. The heterozygosity of the samples (total sample size 294 plants) H _e = 0.301 was considerable higher than the mean values in populations of endemic species (0.076). Based on the results of this study, we identified two groups of O. chankaensis populations (southern and northern), in spite of the absence of marked hiatus between them. Of special interest is the population from Przhewalski Spit, which is a natural reserve of genetic diversity of the species and the putative center of formation of the autotetraploid O. chankaensis.     

Current state of the genetic polymorphism in spring barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) from Russia assessed by the alleles of hordein-coding loci

Starch gel electrophoresis was performed to study the polymorphism of hordeins encoded by the Hrd A, Hrd B, and Hrd F loci in 211 varieties of spring barley. For 41 of these varieties, the genetic formulas were established for the first time. In the two samples of varieties, the comparative analysis of allelic diversity and allele frequencies of hordein-coding loci was carried out. The first sample consisted of 101 spring barley varieties approved for the use on the territory of the Russian Federation in 1999, while the second sample included 160 spring barley varieties that were approved in 2014; 49 of these varieties were common for both samples. It is demonstrated that the current tendency to reduction of the proportion of heterogeneous spring barley varieties is mainly due to the introduction of foreign varieties homogeneous for the hordein-coding loci. At the same time, there is an increase in polymorphism of hordein-coding loci in modern spring barley varieties. The number of alleles for the Hrd A locus increased by five alleles, and for the Hrd B locus, by nine alleles. Along with the alleles recorded earlier in barley landrace populations and varieties bred in 20th century, three novel alleles of the Hrd A locus and four alleles of the Hrd B locus were identified. The number of alleles of the Hrd F locus remained unchanged (four), and the changes in their frequencies were small. At the same time, the changes in frequency observed for some alleles of the Hrd A and Hrd B loci were statistically significant. All newly identified alleles of hordein-coding loci were found with low frequencies (from 0.003 to 0.006), so despite the increased number of alleles, no statistically significant increase in genetic diversity in terms of μ and PIC indices was observed.     

Results of <Emphasis Type="Italic">Camelus dromedarius</Emphasis> and <Emphasis Type="Italic">Camelus bactrianus</Emphasis> Genotyping by Alpha-S<Subscript>1</Subscript>-Casein,Kappa-Casein Loci,and DNA Fingerprinting

Genotyping of Kazakh camels Camelus dromedarius (milk breed) (n = 18) and Camelus bactrianus (meat breed) (n = 18) by alpha-S₁-casein (αs₁-CN) and kappa-casein (κ-CN) loci was conducted using the PCR–RFLP analysis method. A new pair of primers was suggested for the amplification of the CSN3 gene fragment with subsequent cleavage of the reaction products by AluI restriction endonuclease in order to identify the gene genetic variants. DNA polymorphism was detected only for the kappa-casein locus; no genetic polymorphism for alpha-S₁-casein gene was found in the studied populations. Analysis of the results of DNA fingerprinting demonstrated that the band sharing (BS) coefficient between the groups was low enough (0.13), and the genetic distance (D) between Dromedary and Bactrian breeds was 0.305. The results of genotyping of Bactrian and Dromedary Kazakh camel breeds by alpha-S₁-casein, kappa-casein loci, and DNA fingerprinting indicate that the Dromedary breed female camels are more polymorphic as compared with Bactrian.     

Molecular mapping of powdery mildew resistance gene <Emphasis Type="Italic">PmSGD</Emphasis> in Chinese wheat landrace Shangeda using RNA-seq with bulk segregant analysis

Wheat powdery mildew, caused by the fungal pathogen Blumeria graminis f. sp. tritici (Bgt), is one of the most devastating diseases of wheat in China and causes serious yield losses. Resistance genes are urgently needed by wheat breeding programs to combat this disease. In the present study, genetic analysis of powdery mildew resistance was conducted on segregated F₂ and F_2:3 populations derived from the cross of Shangeda (providing good resistance to powdery mildew) and Chancellor (susceptible to powdery mildew). The results showed that the resistance of Shangeda to E09 was controlled by a single recessive gene, tentatively designated as PmSGD. In addition, RNA sequencing of the parental lines Shangeda and Chancellor and the corresponding bulked pools derived from homozygous resistant or susceptible F_2:3 lines was implemented to identify single-nucleotide polymorphisms (SNPs). The PmSGD gene was estimated to be located in the 240–250-Mb region of chromosome 7B based on the characteristics of putative SNP loci distributed on 21 wheat chromosomes. Among the developed SNP markers, 17 (57%) markers were linked to PmSGD flanked by SNP2-57 and SNP2-46, with genetic distances of 0.4 and 0.8 cM, respectively. The reaction patterns of Shangeda and cultivars (lines) carrying the Pm5e, Pmhym, mlxbd, and PmTm4 genes to 22 Bgt isolates indicated that PmSGD may be allelic or very closely linked to those genes. All of the SNP loci linked to PmSGD were used to test 38 cultivars with known Pm gene(s), and the results suggested that these SNP loci are useful for pyramiding PmSGD by marker-assisted selection.     

Genetic diversity and mating system of <Emphasis Type="Italic">Pinus brutia</Emphasis> var. <Emphasis Type="Italic">stankewiczii</Emphasis> Sukacz. in small localities of Sudak (Crimea)

The comparative analysis of genetic variation at 12 polymorphic isozyme loci, as well as the mating system, has been carried out in mature trees and their seed progenies in three small localities of Pinus brutia var. stankewiczii Sukacz. in the region between the town of Sudak and settlement of Novyi Svet in Crimea. We found that embryos maintain the same allelic diversity as parent trees; however, their observed heterozygosity, on average, is lower by 37.4%. The significant deviation of genotype distribution from the expected ratios caused by the deficiency of heterozygotes was observed at 8 out of 12 loci. The multilocus estimate of the out-crossing rate (t _m ) in populations varied from 68.9 to 94.9% with the average of 80.7%.     

Population genetic diversity and geographical differentiation of MHC class II DAB genes in the vulnerable Chinese egret (<Emphasis Type="Italic">Egretta eulophotes</Emphasis>)

Major histocompatibility complex (MHC) genes are excellent markers for the study of adaptive genetic variation occurring over different geographical scales. The Chinese egret (Egretta eulophotes) is a vulnerable ardeid species with an estimated global population of 2600–3400 individuals. In this study, we sampled 172 individuals of this egret (approximately 6 % of the global population) from five natural populations that span the entire distribution range of this species in China. We examined their population genetic diversity and geographical differentiation at three MHC class II DAB genes by identifying eight exon 2 alleles at Egeu-DAB1, eight at Egeu-DAB2 and four at Egeu-DAB3. Allelic distributions at each of these three Egeu-DAB loci varied substantially within the five populations, while levels of genetic diversity varied slightly among the populations. Analysis of molecular variance showed low but significant genetic differentiation among five populations at all three Egeu-DAB loci (haplotype-based ?_ST: 0.029, 0.020 and 0.042; and distance-based ?_ST: 0.036, 0.027 and 0.043, respectively; all P < 0.01). The Mantel test suggested that this significant population genetic differentiation was likely due to an isolation-by-distance pattern of MHC evolution. However, the phylogenetic analyses and the Bayesian clustering analysis based on the three Egeu-DAB loci indicated that there was little geographical structuring of the genetic differentiation among five populations. These results provide fundamental population information for the conservation genetics of the vulnerable Chinese egret.     

Geographic distribution of genetic diversity in populations of Rio Grande Chub <Emphasis Type="Italic">Gila pandora</Emphasis>

In the southwestern United States (US), the Rio Grande chub (Gila pandora) is state-listed as a fish species of greatest conservation need and federally listed as sensitive due to habitat alterations and competition with non-native fishes. Characterizing genetic diversity, genetic population structure, and effective number of breeders will assist with conservation efforts by providing a baseline of genetic metrics. Genetic relatedness within and among G. pandora populations throughout New Mexico was characterized using 11 microsatellite loci among 15 populations in three drainage basins (Rio Grande, Pecos, Canadian). Observed heterozygosity (H_O) ranged from 0.71–0.87 and was similar to expected heterozygosity (0.75–0.87). Rio Ojo Caliente (Rio Grande) had the highest allelic richness (A_R = 15.09), while Upper Rio Bonito (Pecos) had the lowest allelic richness (A_R = 6.75). Genetic differentiation existed among all populations with the lowest genetic variation occurring within the Pecos drainage. STRUCTURE analysis revealed seven genetic clusters. Populations of G. pandora within the upper Rio Grande drainage (Rio Ojo Caliente, Rio Vallecitos, Rio Pueblo de Taos) had high levels of admixture with Q-values ranging from 0.30–0.50. In contrast, populations within the Pecos drainage (Pecos River and Upper Rio Bonito) had low levels of admixture (Q = 0.94 and 0.87, respectively). Estimates of effective number of breeders (N _b ) varied from 6.1 (Pecos: Upper Rio Bonito) to 109.7 (Rio Grande: Rio Peñasco) indicating that populations in the Pecos drainage are at risk of extirpation. In the event that management actions are deemed necessary to preserve or increase genetic diversity of G. pandora, consideration must be given as to which populations are selected for translocation.