Population Genetic Indices Research Articles

Mitochondrial genome analysis across different populations reveals the intraspecific variation and phylogeography of the Caucasian soft tick relapsing fever vector, Ornithodoros (Pavlovskyella) verrucosus (Ixodida: Argasidae)

Territories in southern parts of Eastern Europe and in the Caucasus are endemic for tick-borne relapsing fever (TBRF), caused by Borrelia caucasica. This spirochete is transmitted exclusively by the bites of Ornithodoros verrucosus; however, the distribution and genetic diversity of the tick vector have not been explored. To address this, we performed a phylogeographic study of O. verrucosus specimens collected across a large geographic distribution. We sequenced and analyzed complete mitochondrial genomes of 54 individual O. verrucosus ticks representing 23 geographically diverse populations from Ukraine, Georgia, and Azerbaijan. We detected 47 unique haplotypes, with every collection site exhibiting distinct polymorphisms. This, along with other population genetic indices, suggests little evidence of gene flow between populations. The Bayesian coalescent analysis revealed the presence of four lineages that diverged in the Middle Pleistocene (770–126 kya). Two lineages were widespread and present in all study regions, while the other two were restricted to the southern foothills of the Lesser Caucasus mountain range. The sympatry of these ancient lineages suggests that isolation by environment, in addition to geographic distance, may play a role in the intraspecific divergence of tick populations. Using a phylogeographic approach, we provide a snapshot of genetic diversity in O. verrucosus and discuss the evolutionary history of the tick vector.

GenAPoPop 1.0: A user-friendly software to analyse genetic diversity and structure from partially clonal and selfed autopolyploid organisms.

Autopolyploidy is quite common in most clades of eukaryotes. The emergence of sequence-based genotyping methods with individual and marker tags now enables confident allele dosage, overcoming the main obstacle to the democratization of the population genetic approaches when studying ecology and evolution of autopolyploid populations and species. Reproductive modes, including clonality, selfing and allogamy, have deep consequences on the ecology and evolution of population and species. Analysing genetic diversity and its dynamics over generations is one efficient way to infer the relative importance of clonality, selfing and allogamy in populations. GenAPoPop is a user-friendly solution to compute the specific corpus of population genetic indices, including indices about genotypic diversity, needed to analyse partially clonal, selfed and allogamous polysomic populations genotyped with confident allele dosage. It also easily provides the posterior probabilities of quantitative reproductive modes in autopolyploid populations genotyped at two-time steps and a graphical representation of the minimum spanning trees of the genetic distances between polyploid individuals, facilitating the interpretation of the genetic coancestry between individuals in hierarchically structured populations. GenAPoPop complements the previously existing solutions, including SPAGEDI and POLYGENE, to use genotypings to study the ecology and evolution of autopolyploid populations. It was specially developed with a simple graphical interface and workflow, and comes with a simulator to facilitate practical courses and teaching of population genetics for autopolyploid populations.

The impact of sequencing depth and relatedness of the reference genome in population genomic studies: A case study with two caddisfly species (Trichoptera, Rhyacophilidae, Himalopsyche).

Whole genome sequencing for generating SNP data is increasingly used in population genetic studies. However, obtaining genomes for massive numbers of samples is still not within the budgets of many researchers. It is thus imperative to select an appropriate reference genome and sequencing depth to ensure the accuracy of the results for a specific research question, while balancing cost and feasibility. To evaluate the effect of the choice of the reference genome and sequencing depth on downstream analyses, we used five confamilial reference genomes of variable relatedness and three levels of sequencing depth (3.5×, 7.5× and 12×) in a population genomic study on two caddisfly species: Himalopsyche digitata and H. tibetana. Using these 30 datasets (five reference genomes × three depths × two target species), we estimated population genetic indices (inbreeding coefficient, nucleotide diversity, pairwise F ST, and genome-wide distribution of F ST) based on variants and population structure (PCA and admixture) based on genotype likelihood estimates. The results showed that both distantly related reference genomes and lower sequencing depth lead to degradation of resolution. In addition, choosing a more closely related reference genome may significantly remedy the defects caused by low depth. Therefore, we conclude that population genetic studies would benefit from closely related reference genomes, especially as the costs of obtaining a high-quality reference genome continue to decrease. However, to determine a cost-efficient strategy for a specific population genomic study, a trade-off between reference genome relatedness and sequencing depth can be considered.

Aspergillus flavus genetic structure at a turkey farm.

The ubiquitous environmental fungus Aspergillus flavus is also a life-threatening avian pathogen. This study aimed to assess the genetic diversity and population structure of A. flavus isolated from turkey lung biopsy or environmental samples collected in a poultry farm. A. flavus isolates were identified using both morphological and ITS sequence features. Multilocus microsatellite genotyping was performed by using a panel of six microsatellite markers. Population genetic indices were computed using FSTAT and STRUCTURE. A minimum-spanning tree (MST) and UPGMA dendrogram were drawn using BioNumerics and NTSYS-PC, respectively. The 63 environmental (air, surfaces, eggshells and food) A. flavus isolates clustered in 36 genotypes (genotypic diversity=0.57), and the 19 turkey lung biopsies isolates clustered in 17 genotypes (genotypic diversity=0.89). The genetic structure of environmental and avian A. flavus populations were clearly differentiated, according to both F-statistics and Bayesian model-based analysis' results. The Bayesian approach indicated gene flow between both A. flavus populations. The MST illustrated the genetic structure of this A. flavus population split in nine clusters, including six singletons. Our results highlight the distinct genetic structure of environmental and avian A. flavus populations, indicative of a genome-based adaptation of isolates involved in avian aspergillosis.

Assessment of Molecular Diversity and Heterozygosity in Corn (Zea mays L.) Inbred Lines Using Simple Sequence Repeat (SSR) Markers

In this study, polymerase chain reaction (PCR) was used to genotype 30 corn inbred lines using 32 simple sequence repeat (SSR) markers. The goal was to establish the level and pattern of genetic diversity as well as to define probable heterotic groups of corn inbred lines. The 32 SSR primers detected a total of 238 alleles in a total of 150 individuals analyzed. The mean different number of alleles, effective number of alleles, Shannon’s information index, plus observed (Ho) and expected (He) heterozygosity were estimated (Na = 1.33, Ne = 1.29, I = 0.21, Ho = 0.28, He = 0.15) – exhibiting the highest values for phi079 (Na = 2.00, Ne = 1.96, I = 0.68, Ho = 0.89, He = 0.49) and the lowest for phi050 (Na = 1.00, Ne = 1.00, I = 0.00, Ho = 0.00, He = 0.00). The mean values of Ho > He indicates that the population has a mating system avoiding inbreeding. The high level of overall observed heterozygosity in corn inbred lines (mean Ho = 0.28 > mean He = 0.15) may indicate greater allelic polymorphism present in these populations and the possible mixing of previously isolated materials in the germplasm collection. Polymorphism information content ranged from 0.79 (umc1109) to 0.25 (umc1143), with an overall average value of 0.37, indicating that the loci were moderately low to highly informative and could thus detect and quantify genetic diversity in the population studied. In our maize gene pool, total genetic differentiation is somewhat high (0.57), with an excess of homozygotes. Seventeen (17) SSR loci had negative fixation indices (F), indicating a significant heterozygosity level. The population genetic diversity indices were also computed based on the 30 populations analyzed. The Na, Ne, Shannon’s information index, Ho, and He varied from population S8L17 to S8L27 with mean values of 1.327, 1.293, 0.214, 0.284, and 0.151, respectively. Populations showed negative F values, indicating significantly higher heterozygosity, whereas polymorphic loci had a mean value of 32.71%. The estimated molecular variance among the corn population was 2.29 and 3.06 for the variance within populations with a total of 5.35. The results of AMOVA also revealed that genetic variation within individuals accounts for 57% of overall genetic diversity, whereas among populations variability accounts for 43%. The cluster analysis, population structure analysis, and principal coordinate analysis revealed the presence of two distinct subpopulations. As a result, the findings of this study provide a foundation for identifying heterotic groups and parental selection, providing a source of unique alleles for future maize breeding efforts.

Population genetic indices of veined Rapa whelk groups of the Black Sea remote regions

Abstract Genetic structure and genetic distance of Rapana venosa populations from remote regions of the Black Sea (Odessa Bay and eastern Crimea, Ukraine) were defined. Despite the significant difference in morphometric parameters, the investigated samples of mollusks are genetically very similar, and the distance between them is at the level of local populations. Common features of observed groups of Rapana in the northern part of the Black Sea are the unequal occurrence of some alleles and genotypes, a high level of heterozygosity and nonequilibrium in the Hardy-Weinberg equation. The gene flow is the most significant of the evolutionary factors that form the genetic structure of Rapana venosa populations.

A Study on β-Casein Gene Polymorphism in Crossbred Cattle and Murrah / Graded Murrah Buffalo in Tamil Nadu

Background: Majority of the people believed that, only the native breeds have A2 milk than exotic or crossbred animals. There is no enough research on milk protein variants have been carried out in Indian zebu cattle. Present study was conducted to screen more number of crossbred cattles and buffaloes in Tamil Nadu to identify the frequency of A1 and A2 alleles in the population.Methods: The study was conducted on 68 cattle and 172 murrah / graded murrah buffaloes to explore the polymorphic variants of β-casein gene. Genomic DNA was extracted by phenol-chloroform method. Polymerase Chain Reaction (PCR) was performed with allele specific primers to amplify a 244 bp long fragment of beta-casein gene and visualized in 2% agarose gel electrophoresis. The population genetic indices were calculated based on the formulas.Result: In the present study revealed higher level of A2A2 genotype frequency (1.00) and fixation of A2 allele in kangayam cattle and murrah / graded murrah buffalo. The observed frequency of A1A1, A1A2 and A2A2 genotypes were 0.38,0.62 and 0.00 for jersey crossbred and 0.29, 0.71 and 0.00 for HF crossbred cattle. The range of Expected homozygosity (0.50 to 1.00), polymorphism information content (0.30 to 0.38), effective number of alleles (1.00 to 2.00) and level of possible variability realization value (44.54% to 100%) reflected existence of medium genetic variability in studied population.

Strong gene flow explains lack of mating system variation in the perennial herb, Vincetoxicum hirundinaria, in a fragmented landscape

Fragmented landscapes may have implications for the genetic structure of populations and for the microevolution of plant species. In particular, landscape fragmentation and/or population isolation might affect the evolution of plant mating systems. Here, we study the consequences of landscape fragmentation on the genetic structure of populations of a perennial herb, Vincetoxicum hirundinaria with a mixed mating system. Our study area, the south‐western Finnish archipelago, was formed after the glacial ice sheet started to retreat 12 000 years ago. Due to the isostatic land uplift following the glacial retreat, suitable habitats have been formed gradually, and as a consequence, populations of V. hirundinaria differ in age, size and their degree of isolation in the area. We hypothesized that a mixed‐mating system has been selected for in these populations due to the advantage of self‐fertilization in newly colonized areas and the advantage of outcrossing in adaptation to heterogeneous environments. To test this hypothesis, we collected seeds of open‐pollinated flowers from 13 V. hirundinaria populations differing in size, age and isolation, and used 15 microsatellite markers to perform progeny‐array analysis to estimate population‐level outcrossing rates, population genetic indices and population structure. We found that V. hirundinaria is almost completely outcrossing in the study area with no signs of past self‐fertilization and/or mating among relatives. The overall low inbreeding coefficients indicate that even in small populations mating among relatives is rare. High allelic richness of both maternal and offspring genotypes as well as limited genetic differentiation among the studied populations indicate strong gene flow among them. Our findings suggest that V. hirundinaria has successful seed and pollen dispersal among populations that has allowed colonization of new habitats in this fragmented landscape and led to a genetically well‐mixed group of populations at the scale of the study.

The Combined Effect of Haplodiplonty and Partial Clonality on Genotypic and Genetic Diversity in a Finite Mutating Population.

Partial clonality is known to affect the genetic composition and evolutionary trajectory of diplontic (single, free-living diploid stage) populations. However, many partially clonal eukaryotes exhibit life cycles in which somatic development occurs in both haploid and diploid individuals (haplodiplontic life cycles). Here, we studied how haplodiplontic life cycles and partial clonality structurally constrain, as immutable parameters, the reshuffling of genetic diversity and its dynamics in populations over generations. We assessed the distribution of common population genetic indices at different proportions of haploids, rates of clonality, mutation rates, and sampling efforts. Our results showed that haplodiplontic life cycles alone in finite populations affect effective population sizes and the ranges of distributions of population genetic indices. With nonoverlapping generations, haplodiplonty allowed the evolution of 2 temporal genetic pools that may diverge in sympatry due to genetic drift under full sexuality and clonality. Partial clonality in these life cycles acted as a homogenizing force between those 2 pools. Moreover, the combined effects of proportion of haploids, rate of clonality, and the relative strength of mutation versus genetic drift impacts the distributions of population genetics indices, rendering it difficult to transpose and use knowledge accumulated from diplontic or haplontic species. Finally, we conclude by providing recommendations for sampling and analyzing the population genetics of partially clonal haplodiplontic taxa.

Exploring the Genetic Consequences of Clonality in Haplodiplontic Taxa.

Partially clonality is an incredibly common reproductive mode found across all the major eukaryotic lineages. Yet, population genetic theory is based on exclusive sexuality or exclusive asexuality, and partial clonality is often ignored. This is particularly true in haplodiplontic eukaryotes, including algae, ferns, mosses, and fungi, where somatic development occurs in both the haploid and diploid stages. Haplodiplontic life cycles are predicted to be correlated with asexuality, but tests of this prediction are rare. Moreover, there are unique consequences of having long-lived haploid and diploid stages in the same life cycle. For example, clonal processes uncouple the life cycle such that the repetition of the diploid stage via clonality leads to the loss of the haploid stage. Here, we surveyed the literature to find studies that had genotyped both haploid and diploid stages and recalculated population genetic summary metrics for seven red algae, one green alga, three brown algae, and three mosses. We compared these data to recent simulations that explicitly addressed the population genetic consequences of partial clonality in haplodiplontic life cycles. Not only was partial clonality found to act as a homogenizing force, but the combined effects of proportion of haploids, rate of clonality, and the relative strength of mutation versus genetic drift impacts the distributions of population genetic indices. We found remarkably similar patterns across commonly used population genetic metrics between our empirical and recent theoretical expectations. To facilitate future studies, we provide some recommendations for sampling and analyzing population genetic parameters for haplodiplontic taxa.

Molecular detection of hemotropic mycoplasmas (hemoplasmas) in domestic cats (Felis catus) in Romania

BackgroundThe hemotropic mycoplasmas (hemoplasmas) of the genus Mycoplasma are recognized as important bacteria that parasitize red blood cells, causing hemolytic anemia in many mammalian species, including cats. No information is available concerning the presence of feline hemoplasma infections in cats in Romania. Thus, the objective of the present study was to provide data on the occurrence and molecular characterization of hemotropic mycoplasmas in client-owned cats in Romania.MethodsBlood samples from 51 unhealthy cats, originating from Timişoara Municipality, Romania, were screened for the presence of hemoplasmas using conventional polymerase chain reaction (PCR) targeting the 16S rRNA gene and sequencing assays. PCR-positive samples were subsequently analyzed by phylogenetic and population genetic analysis.ResultsMolecular analysis revealed 11 (21.6%) positive samples, consisting of 8 (72.7%) Candidatus Mycoplasma haemominutum and 3 (27.3%) Mycoplasma haemofelis confirmed positives. Candidatus Mycoplasma turicensis was not detected, and no co-infections were registered. No significant associations (p > 0.05) were found between the hemoplasma infection status and age, gender, breed, presence of ectoparasites, feline leukemia virus/feline immunodeficiency virus positivity of cats, or the sampling season. However, outdoor access was positively associated (p = 0.049) with infection and could be considered a risk factor (OR = 4.1) in acquiring feline hemotropic mycoplasmas. Phylogenetic analysis revealed that our sequences clustered with those selected from the GenBank database in two distinct clades. The registered population genetic indices were strongly supportive of the great variance in sequences between the recorded Mycoplasma species.ConclusionsThe findings support the occurrence of feline hemoplasma infections in previously uninvestigated territories of Europe, providing useful information for small animal practitioners. To our knowledge, the present survey is the first reported molecular evidence of feline hemoplasma infections in Romania.

Genetic Variants of β-casein Gene in Indigenous and Exotic Dairy Cattle Breeds in Sri Lanka

Background: Bovine milk contains two types of β-casein (CSN2); A1 and A2, in which A1 type has shown associations with certain health issues. This study was conducted to identify the abundance of CSN2 A1/A2 variants in European and indigenous dairy breeds in Sri Lanka. Methods: The study included 123 Ayrshire, 101 Holstein Friesian and 92 indigenous White cattle (Bos indicus) populations. Genotyping was performed by PCR-RFLP method using Dde1. Allele and genotype frequencies and population genetic indices were calculated. Result: Results showed A1A2 to be predominant in both Holstein Friesian (0.63) and Ayrshire (0.68) populations while A2A2 (0.82) was predominant in the White cattle population. A1 and A2 allele frequencies were 0.52 and 0.48 in Ayrshire; 0.39 and 0.61 in Holstein Friesian and 0.09 and 0.91 in White cattle populations. Ayrshire and Holstein Friesian populations showed significant deviation from the Hardy-Weinberg equilibrium (p£0.05). When compared to the imported breeds, the White cattle population showed inbreeding and less genetic diversity.

A Study on Keratin-Associated Protein (KAP) 3.2 Gene and Its Polymorphism in Sandyno Breed of Sheep

The current study investigates the polymorphic patterns of keratin-associated protein (KAP) 3.2 gene in Sandyno breed of sheep. Genomic DNA was isolated from blood samples of 51 numbers of Sandyno breed. Ovine specific primer associated PCR amplification of KAP 3.2 gene revealed product at 393 bp and genotyped by PCR-SSCP (Single Strand Conformation Polymorphism) method and visualized under silver staining technique. KAP 3.2 gene locus revealed 3 genotypes, viz. AA, AB and BB with a frequency of 0.84, 0.16 and 0 in Sandyno breed with allele frequencies of A(0.92) and B(0.08). Regarding population genetic indices, the effective number of alleles (Ne) for KAP 3.2 in Sandyno breed of sheep was found to be 1.1716. The PIC values was 0.1356 and FIS values was negative (– 0.0864) in this breed. The result revealed that the selected population of Sandyno breed of sheep was in Hardy-Weinberg equilibrium without any significant deviation from the population mean and was monomorphic for KAP 3.2 gene.

Evidence for Plio-Pleistocene Duck Mussel Refugia in the Azov Sea River Basins

Freshwater mussels (Bivalvia: Unionoida) play an important role in freshwater habitats as ecosystem engineers of the water environment. Duck mussel Anodonta anatina is widely distributed throughout Europe, Siberia, and Western and Central Asia, which makes it a convenient object for biogeographic studies. In this study, we analyzed the divergence of A. anatina populations and discovered a separate genetic lineage distributed in rivers of the Azov Sea basin. This was confirmed by the high genetic distances between this group and previously defined populations, and by the position of this clade in the Bayesian phylogeny calibrated by an external substitution rate. Based on our approximate Bayesian computation (ABC) analysis, biogeographic scenarios of A. anatina dispersal in Europe and Northern, Western, and Central Asia over the Neogene–Quaternary were simulated. The haplogroup’s isolation in the rivers of the Azov Sea basin most likely occurred in the Late Pliocene that was probably facilitated by rearrangement of freshwater basins boundaries in the Ponto-Caspian Region. Population genetic indices show the stability of this group, which allowed it to exist in the river basins of the region for a long time. The discovery of a long-term refugium in the rivers of the Azov Sea led to a better understanding of freshwater fauna evolution in the Neogene–Quaternary and highlighted the importance of conservation of these freshwater animals in the region as a source of unique genetic diversity.

Comprehensive study based on mtDNA signature (nad1) providing insights on Echinococcus granulosus s.s. genotypes from Pakistan and potential role of buffalo-dog cycle

Pakistan has long been considered neglected endemic region for Echinococcus granulosus. Limited surveillance studies have failed to epidemiologically draw complete picture on geographical presence and etiological agents of cystic echinococcosis. Amidst such lacunae, current study explored main transmission routes of this disease through molecular characterization of hydatid cyst isolates obtained from sheep (n = 35), goats (n = 26), cattle (n = 30) and buffalo (n = 30) from the four provinces of Pakistan. Two strains of E. granulosus sensu stricto, G1/G3, and their haplotypes were observed to be cycling in sympatry in the domestic ungulate populations. G3 genotype had higher prevalence (66.94%) in the hosts compared to G1 genotype (33.06%) which was not surprising, considering the large buffalo population in Pakistan. Haplotypic analysis revealed presence of 9 different haplotypes configured in a double clustered network with two centrally positioned haplotypes referred to as G3 (PKH1) and G1 (PKH6). Population demographics and genetic variability indices suggested expanding parasitic population in multiple host spectrum. Elucidating local transmission patterns of E. granulosus sensu stricto, buffalo-dog cycle emerged as one of the dominant causes of G3 dispersal in contrary to other global studies. Adaptability of G3 to environmental conditions of Pakistan and high affinity for buffaloes emphasize on heterogeneous nature of this strain in contrast to G1. However, more studies involving larger datasets and mitochondrial sequences could confirm this hypothetically formulated inference.

Patterns of spatial genetic structures in Aedes albopictus (Diptera: Culicidae) populations in China

BackgroundThe Asian tiger mosquito, Aedes albopictus, is one of the 100 worst invasive species in the world and the vector for several arboviruses including dengue, Zika and chikungunya viruses. Understanding the population spatial genetic structure, migration, and gene flow of vector species is critical to effectively preventing and controlling vector-borne diseases. Little is known about the population structure and genetic differentiation of native Ae. albopictus in China. The aim of this study was to examine the patterns of the spatial genetic structures of native Ae. albopictus populations, and their relationship to dengue incidence, on a large geographical scale.MethodsDuring 2016–2018, adult female Ae. albopictus mosquitoes were collected by human landing catch (HLC) or human-bait sweep-net collections in 34 localities across China. Thirteen microsatellite markers were used to examine the patterns of genetic diversity, population structure, and gene flow among native Ae. albopictus populations. The correlation between population genetic indices and dengue incidence was also examined.ResultsA total of 153 distinct alleles were identified at the 13 microsatellite loci in the tested populations. All loci were polymorphic, with the number of distinct alleles ranging from eight to sixteen. Genetic parameters such as PIC, heterozygosity, allelic richness and fixation index (FST) revealed highly polymorphic markers, high genetic diversity, and low population genetic differentiation. In addition, Bayesian analysis of population structure showed two distinct genetic groups in southern-western and eastern-central-northern China. The Mantel test indicated a positive correlation between genetic distance and geographical distance (R2 = 0.245, P = 0.01). STRUCTURE analysis, PCoA and GLS interpolation analysis indicated that Ae. albopictus populations in China were regionally clustered. Gene flow and relatedness estimates were generally high between populations. We observed no correlation between population genetic indices of microsatellite loci in Ae. albopictus populations and dengue incidence.ConclusionStrong gene flow probably assisted by human activities inhibited population differentiation and promoted genetic diversity among populations of Ae. albopictus. This may represent a potential risk of rapid spread of mosquito-borne diseases. The spatial genetic structure, coupled with the association between genetic indices and dengue incidence, may have important implications for understanding the epidemiology, prevention, and control of vector-borne diseases.

Overall stability in the genetic structure of a Zymoseptoria tritici population from epidemic to interepidemic stages at a small spatial scale

Subpopulations of the wheat pathogen Zymoseptoria tritici (26 sample groups composed of 794 isolates) were collected in two nearby wheat fields in the Paris basin, during both epidemic and inter-epidemic periods of three successive years (2009–2013). In addition to the type of inoculum (ascospores vs. pycnidiospores), the alternative presence of wheat debris allowed taking into account its putative origin (local vs. distant). We used a molecular epidemiology approach, based on population genetic indices derived from SSR marker analysis, to describe putative changes in the structure and genotypic diversity of these subpopulations over 3 years, at a spatiotemporal scale consistent with epidemiological observations. Genetic structure was broadly stable over time (within and between years) and between fields, however with weak population differentiation over time. All subpopulations displayed very high diversity and the occurrence of regular sexual reproduction was confirmed in the two fields. A significant increase of the MAT1–1/MAT1–2 ratio was observed over the course of the epidemics. This original finding suggests a competitive advantage of MAT1–1 strains consistently with their greater pathogenicity reported in the literature and may reveal undescribed adaptation. Finally, we found that the period, the type of inoculum and its putative origin had little effect on the short term evolution of the local population of Z. tritici. Fungal population size and diversity are apparently large enough to prevent genetic drift at this fine spatiotemporal scale, and more likely short distance migration contributes strongly to the stabilization of genetic diversity among and within plots.

Genetic characterization of Markhoz goat breed using microsatellite markers.

The use of molecular markers can support the management of endangered populations and should be combined with appropriate breeding strategies to improve productive traits avoiding the decline of the breed. The genetic variability at 10 microsatellite loci were investigated in a sample of 100 unrelated Markhoz goats (77 females and 23 males). The investigated population was reared at the Sanandaj Markhoz goat Performance Testing Station in Kurdistan, Iran. Markhoz goat, a multipurpose breed, is one of the most valuable genetic resources in Iran. All the studied loci were found to be polymorphic and a total number of 52 alleles were identified with an average number of alleles of 5.2. Moreover, some population genetic indices, such as observed and expected heterozygosity, observed and expected number of alleles, Shannon's index, Nei's expected heterozygosity, and polymorphism information content were also calculated. Despite the decreasing population size, Markhoz goat genetic diversity is still conserved. The breed seems to have a good level of genetic variability and, as a consequence, a potential margin of adaptability to environment and for future genetic improvement.

GENETIC AND BIOCHEMICAL PECULIARITIES OF SOYA MUTANT LINES

The aim of the work was to study genetic and biochemical peculiarities of soya lines, obtained after treatment of seeds with chemical mutagens. In order to realise the stated aim the following tasks were set: 1) to determine population-genetic indices of soya samples, 2) to establish genetic distances between lines and parental material, 3) to determine potential correlative relationship between loci of the enzymes studied and other genetic systems, as well as morphological and physiological parameters. Material . The lines, obtained by chemical mutagenesis of Femida variety. Soya varieties Femida and Korada. Methods . Electrophoresis. Allozyme analysis. Enzymes of exchange of active oxygen forms: NADP N-oxydase, peroxydase and superoxyzedismutase were used as protein markers. Methods of population genetics. Correlation analysis. Methods of descriptive statistics. Computer data processing. Results. With respect to the loci studied the soya samples demonstrated considerable polymorphism, constituting 79 %.Considerable genetic heterogeneity of the soya samples was determined as to gene-enzyme systems. Wright and Gst-statistics showed that genetic heterogeneity is connected both with individual and with internal- and inter-group variability. Contribution of various types of variability into general differentiation was approximately equal. Inter-grout variability was manifested in form on different occurrence of different alleles of enzyme loci and different frequency of alternative genotypes. In addition to quantitative change of genotype frequency, other forms of genotype composition transformation were observed. So, fraction of heterozygous genotypes by loci NPOX-3, -4, -5, as well as SOD-3 increased in mutant lines in comparison with parental form. On the contrary, frequency of heterozygotes decreased in loci POX-3 and POX-6. Inversion of frequencies of homozygotes by alternative alleles was observed in locus POX-6 in mutant forms in comparison with output variety. The described changes of genotypic composition also observed in comparison of the studied varieties – Femida and Korada. On the whole, varieties Femida and Korada were different from each other by 10 of 15 polymorphic loci (67 %). Line M29 turned out to be more differentiated with considerable contribution to the general heterogeneity of individual variability. With considerable genetic heterogeneity the average heterozygosity by the studied loci was inconsiderable for the entire totality of samples and constituted 7 %. It was shown that genetic distances between different groups of soya are within intraspecific limits in spite of high level of heterogeneity. Basing on Neya index line M323 was more remote from parental form than sisterly mutant line. Reliable correlative relationship between some loci of izozymes and some economically valuable features of soya, as well as photosensitivity genome E7 were determined. The strongest interrelationship was observed for peroxidise and superoxidedismutase, which can testify to an important role of the said enzymes in regulation of plant development processes.

Low Levels of Population Structure among Geographically Distant Populations of Pteropus vampyrus (Chiroptera: Pteropodidae)

Pteropus vampyrus, the largest bat in the world, has a broad geographic range covering much of Southeast Asia. The wide distribution of P. vampyrus and its ability to cross oceanic expanses makes management of this threatened species an international concern. Pteropus vampyrus is an essential seed disperser and pollinator of rain forest trees, many of which are ecologically and economically important. Understanding population dynamics of P. vampyrus is thus critical to addressing conservation issues and global health concerns. We used phylogenetic inference and population genetic indices to infer past gene flow between populations of P. vampyrus throughout most of the species' range. Population genetic parameters indicate low levels of nucleotide variability with high haplotype diversity across its range, implying a demographic scenario of recent population expansion after a bottleneck. Subspecies were not found to be monophyletic from the genetic data, which may reflect some level of genetic variation on even shallower time scales. The low level of population genetic structure throughout the species range is not necessarily surprising given its high vagility and seasonal migratory behavior. However, it cannot be entirely excluded that these results may reflect historical connectivity or lineage sorting issues rather than more recent persistent gene flow. These findings highlight the need for international cooperation and monitoring to ensure persistence of populations and to create a species management plan that can protect the species throughout its range. Increased genetic sampling is needed to ascertain P. vampyrus' commonly used dispersal routes and to assess the possibility of asymmetric gene flow among populations.