Interpopulation Genetic Diversity Research Articles

DNA barcoding, phylogeography and evolutionary dynamics of Chrysichthys auratus

This study embarked on an exploration into the genetic structure and evolutionary history of the Chrysichthys auratus species, leveraging PCR amplification, phylogenetic trees, and haplotype networks. Specific DNA segments were successfully amplified and visualized through electrophoresis. Newly obtained sequences were Bank into GenBank and given accession numbers (OR730807-OR730808-OR730809). The Neighbor-Joining method provided insights into the evolutionary relationships among taxa, further augmented by bootstrap values and the Tamura 3-parameter method. A comprehensive geographical haplotype network showcased pronounced genetic differentiation, especially between remote populations. Nonetheless, shared haplotypes between proximate regions indicated either ancestral genetic connections or ongoing gene flow. Employing the COI-DNA barcodes, an in-depth understanding of intra- and inter-populational genetic diversity was achieved. The study's findings unravel the intricate genetic landscape and evolutionary dynamics of C. auratus, offering novel perspectives into its demographic history across its vast native habitat.

Serpentine environment prevails over geographic distribution in shaping the genetic diversity of Medicago lupulina L.

Edaphic conditions of serpentine soils, naturally rich in heavy metals, act as a strong selection pressure that shapes specific metal-tolerant ecotypes. Medicago lupulina L. (black medick) is not only a widespread plant species that prefers calcareous and dry soil types but also grows at the borders of serpentine formations. It can also be found in waste and disturbed habitats. This is a species with reported phytoremediation potential, however, there is no published data regarding the impact of the environment on the genetic distribution of this species. The aim of our research was to explore how selection pressure of serpentine soils affects genetic diversity of M. lupulina and to test heavy-metal accumulation capacity of this species. Specimens of 11M. lupulina populations were collected from serpentine outcrops located in Central and Eastern Bosnia as well as from non-serpentine sites. Soil and plant samples were analyzed for the total contents of heavy metals using air-acetylene flame atomic absorption spectroscopy. Genetic diversity was analyzed using AFLP (Amplified Fragment Length Polymorphism) markers. Serpentine soils showed high nickel, cobalt, chromium and iron concentrations. Nickel and manganese concentrations in soil samples and plant material showed statistically significant correlation. Although plants in two populations show the ability to extract Ni, M. lupulina does not show hyperaccumulating properties. Despite severe selective pressure, genetic diversity in serpentine populations is not reduced. Analyses of intrapopulation and interpopulation genetic diversity showed significant genetic differentiation among populations which is not related to their geographic distance. Population from non-metalliferous soil showed clear separation from all other populations. Diversity data suggest that serpentine populations maintain genetic diversity by undetected mechanisms and that edaphic factors rather than geography influence genetic structure analyzed M. lupulina populations.

Genetic connectivity constrained by natural barriers in a key agricultural pest: insights from mitochondrial DNA analysis

In the context of anthropogenic global change, the study of landscape effects on species movement has garnered increasing attention. Landscape genetics offer indirect yet attractive means to capture species dispersal events across generations and their interaction with landscapes. However, landscape genetic patterns tend to exhibit significant variations across taxa and rely on the molecular makers adopted. Here, we investigated how landscapes influence population connectivity of an important tea pest, Empoasca onukii, using mitochondrial DNA sequences of 1,518 individuals from 57 locations in mainland China and offshore islands. We analyzed the inter-population genetic divergence and integrated multiple models to explicitly quantify their association with geographic distance, environmental heterogeneity, and landscape barriers. Analyses revealed a reduction in gene flow on islands, along the Yangtze River, and across mountainous regions of Western China. Models explicitly detected the predominant contributions of topographic complexity to population divergence and evidenced that mountains may serve as effective dispersal barriers for E. onukii. These results suggest that the limited gene exchange resulting from low population connectivity among mountains might generate the observed patterns of mitochondrial genetic variations, which contrasts the climate-related pattern previously observed on microsatellites. The findings enhance our comprehension of the evolutionary and epidemic dynamics of E. onukii, and highlight the demand of considering species-specific traits when studying population landscape genetic patterns. Moreover, the study emphasizes the necessity of employing multiple molecular markers to comprehensively elucidate landscape effects on population connectivity across diverse species for valuable insights into biodiversity conservation, pest control, and other management decisions.

Interpopulational genetic diversity in the medically important scorpion Tityus obscurus (Scorpiones: Buthidae) from northeastern Brazilian Amazonia

ABSTRACT Scorpion envenoming is considered a public health problem in Brazil. A recent study described a variation in the clinical outcome of envenoming by Tityus obscurus in two populations separated by 850 km in the northeastern Amazon region. Our aim was to evaluate whether such clinical and toxinological variations are associated with underlying differences in genetic diversity between these two T. obscurus populations. We obtained DNA from five individuals of each population, in the municipalities of Belém and Santarém, located east and west of the state of Pará, Brazil, respectively. Gene regions encoding mitochondrial DNA (mtDNA) markers cytochrome oxidase subunit I (COI) and ribosomal 16S RNA (16S) were amplified and sequenced. Phylogenetic analyses were performed using maximum likelihood (ML) and Bayesian inferences (BA) for both molecular data (COI and 16S). The sampled T. obscurus populations corresponded to two distinct mtDNA lineages (genetic distance COI K2 P = 0.08 to 0.13; 16S K2 P = 0.10 to 0.11) with no shared mutations between groups and well supported by ML and BA inferences. Based on the divergence values found between eastern and western populations (COI, 0.07 to 0.12; 16S, 0.10), our study confirms the genetic heterogeneity of T. obscurus populations within the state of Pará, which correlates with observed venom and clinical differences, and reinforces the need for mapping the distribution of haplotypes throughout the geographic range of T. obscurus, to aid in future epidemiological, toxinological, and evolutionary studies.

Development of nuclear microsatellite markers in Yerba mate (Ilex paraguariensis A. St. Hil.) from whole-genome sequence data

AbstractIlex paraguariensis A. St.-Hil. (yerba mate) (Aquifoliaceae Bercht. & J. Presl) is a plant species with great economic and cultural importance because its leaves are processed and ground to make infusions like mate or tereré. The species is distributed in a continuous area that includes Southern Brazil and part of Paraguay and Argentina. Uruguay represents the Southern distribution limit of the species, where small populations can be found as part of ravine forests. Although there are previous reports of molecular markers for this and other species in the genus, the available markers were not informative enough to represent the intra- and interpopulation genetic diversity in marginal Uruguayan populations. In this study, we developed highly informative polymorphic microsatellite markers to be used in genetic studies in I. paraguariensis. Markers were identified in contigs from the genome sequence of two individuals and then tested for amplification and polymorphism content in a diverse panel. Markers which passed these filters were tested on populations from Uruguay. They detected higher diversity within populations (in terms of number of alleles and heterozygosity) than previously reported, and levels of heterozygosity similar to those reported for two Brazilian populations. This subset of seven markers were successfully multiplexed, substantially reducing the costs of the analysis. Combined with previously reported nuclear and plastid markers, they can be used to evaluate the genetic diversity of rear-edge populations, identify genotypes for paternity studies and provide relevant information for the conservation and management of germplasm.

Inter-Population Genetic Diversity and Clustering of Merozoite Surface Protein-1 (pkmsp-1) of Plasmodium knowlesi Isolates from Malaysia and Thailand.

The genetic diversity of pkmsp-1 of Malaysian Plasmodium knowlesi isolates was studied recently. However, the study only included three relatively older strains from Peninsular Malaysia and focused mainly on the conserved blocks of this gene. In this study, the full-length pkmsp-1 sequence of recent P. knowlesi isolates from Peninsular Malaysia was characterized, along with Malaysian Borneo and Thailand pkmsp-1 sequences that were retrieved from GenBank. Genomic DNA of P. knowlesi was extracted from human blood specimens and the pkmsp-1 gene was PCR-amplified, cloned, and sequenced. The sequences were analysed for genetic diversity, departure from neutrality, and geographical clustering. The pkmsp-1 gene was found to be under purifying/negative selection and grouped into three clusters via a neighbour-joining tree and neighbour net inferences. Of the four polymorphic blocks in pkmsp-1, block IV, was most polymorphic, with the highest insertion-deletion (indel) sites. Two allelic families were identified in block IV, thereby highlighting the importance of this block as a promising genotyping marker for the multiplicity of infection study of P. knowlesi malaria. A single locus marker may provide an alternate, simpler method to type P. knowlesi in a population.

Molecular and cytogenetic evidence for sibling species in the Chagas disease vector Triatoma maculata.

Triatoma maculata (Hemiptera, Reduviidae, Triatominae) occurs across dry-to-semiarid ecoregions of northern South America, where it transmits Trypanosoma cruzi, causative agent of Chagas disease. Using 207 field-caught specimens from throughout the species' range, mitochondrial(mt) DNA sequence data, and cytogenetics, we investigated inter-population genetic diversity and the phylogenetic affinities of T. maculata. Mitochondrial DNA sequence analyses (cytb and nd4) disclosed a monophyletic T. maculata clade encompassing three distinct geographic groups: Roraima formation (Guiana shield), Orinoco basin, and Magdalena basin (trans-Andean). Between-group cytb distances (11.0-12.8%) were larger than the ~7.5% expected for sister Triatoma species; the most recent common ancestor of these T. maculata groups may date back to the late Miocene. C-heterochromatin distribution and the sex-chromosome location of 45S ribosomal DNA clusters both distinguished Roraima bugs from Orinoco and Magdalena specimens. Cytb genealogies reinforced that T. maculata is not sister to Triatoma pseudomaculata and probably represents an early (middle-late Miocene) offshoot of the 'South American Triatomini lineage'. In sum, we report extensive genetic diversity and deep phylogeographic structuring in T. maculata, suggesting that it may consist of a complex of at least three sibling taxa. These findings have implications for the systematics, population biology, and perhaps medical relevance of T. maculata sensu lato.

Genetic Structure and Colonization of North America by Depressaria depressana (Fabricius 1775) (Lepidoptera: Depressariidae) over 15 Years; Contrasts with Westward Expansion of Depressaria radiella (Goeze, 1783) over 160 Years.

Simple SummaryAs invasive insect species can disrupt agriculture, ecosystem functions, and human health, monitoring the spread of newly invasive insects is a high priority. The purple carrot-seed moth Depressaria depressana, a European species first reported in North America in 2008, specializes on reproductive structures of taxa throughout the family Apiaceae and thus presents a potential threat to native North American umbellifers. We assessed interpopulational genetic diversity of D. depressana across its eastern North American invasion front and compared those values to available data for European populations. We also compared this diversity with genetic diversity estimates for populations of Depressaria radiella (parsnip webworm), a European species introduced to North America more than 160 years ago that is essentially restricted to two apiaceous genera throughout its native and invasive ranges. Documenting the historical spread of D. radiella with museum and literature records, we found D. depressana displays greater genetic diversity than D. radiella and is colonizing North America more rapidly; greater genetic diversity may facilitate faster colonization via establishment on a wider range of hostplants. The contrast in colonization by these two species may inform management practices for invasive insects utilizing a broad versus narrow array of hosts within a single plant family.Depressaria depressana, the purple carrot seed moth, is a Eurasian species first reported in North America in 2008 and currently undergoing range expansion. This invasion follows that of its Eurasion congener Depressaria radiella (parsnip webworm), first documented in North America 160 years ago. Unlike D. depressana, which utilizes hostplants across multiple tribes of Apiaceae, Depressaria radiella is a “superspecialist” effectively restricted in its native and non-indigenous ranges to two closely related apiaceous genera. We investigated the genetic structure of D. depressana populations across latitudinal and longitudinal gradients in the eastern United States by constructing COI haplotype networks and then comparing these with haplotype networks constructed from available COI sequence data from contemporary European D. depressana populations and from European and North American D. radiella populations. Haplotype data revealed higher genetic diversity in D. depressana, indicating high dispersal capacity, multiple introductions, and/or a genetically diverse founding population. Museum and literature records of D. radiella date back to 1862 and indicate that range expansion to the West Coast required more than 50 years. Higher levels of genetic diversity observed in D. depressana compared to its congener may indicate a greater propensity for dispersal, colonization and establishment in its non-indigenous range.

Intra- and Inter-Population Genetic Diversity of “Russello” and “Timilia” Landraces from Sicily: A Proxy towards the Identification of Favorable Alleles in Durum Wheat

Climate change and global population growth call for urgent recovery of genetic variation from underexploited or unexplored durum wheat (Triticum turgidum ssp. durum) landraces. Indeed, these untapped genetic resources can be a valuable source of favorable alleles for environmental adaptation and tolerance or resistance to (a)biotic stress. In southern Italy, in addition to the widespread modern and highly productive durum wheat cultivars, various landraces have been rediscovered and reused for their adaptation to sustainable and low-input cropping systems and for their peculiar qualitative characteristics. Sicily is a semiarid area rich in landraces, some of which are independently reproduced by many farmers. Among these, “Timilia” and “Russello” have been independently grown in various areas and are now cultivated, mostly under organic systems, for their hypothetical greater benefits and height, which give them a high level of competitiveness against weeds despite their low yield potential. So far, there is little information on the genetic variations of “Timilia” and “Russello” despite their putative origin from a common funder. This work aims to dissect the genetic variation patterns of two large germplasm collections of “Timilia” and “Russello” using SNP genotyping. The analysis of intra- and inter-population genetic variation and the identification of divergent loci between genetic groups showed that (i) there are two “Russello” genetic groups associated with different Sicilian geographical areas, which differ in important traits related to gluten quality and adaptation, and (ii) the individuals of “Timilia”, although presenting wide genetic variation, have undergone a conservative selection, likely associated with their distinctive traits. This work paves the way for a deeper exploration of the wide genetic diversity in Sicilian landraces, which could be conveniently exploited in future breeding programs, and points out that intra-population genetic diversity should be taken into account when ‘conservation varieties’ are to be registered in national registers of crops.

Genetic divergence and phylogenetic relationship of the rabbitfish Siganus rivulatus inferred from microsatellite and mitochondrial markers

The rabbit fish, Siganus rivulatus, is a Mediterranean non-endogenous species, that has succeeded in migrating to the different coasts of the Mediterranean Sea. The success of this species in the new environment, with different trophic, biotic, and physical conditions, inspired the study of genetic variation between the Rea Sea and Mediterranean Sea populations. The current study aims to use microsatellite (SSR) and mitochondrial DNA sequence (mtDNA) markers to determine the genetic divergence and phylogenetic relationship of S. rivulatus from the Red Sea and the Mediterranean Sea. A total of 200 S. rivulatus samples (42.50 ± 3.89 gm) were collected from the Red Sea and the Mediterranean Sea. Twelve SSR loci were screened to detect genetic differentiation, in addition to those in mtDNA. The results for the SSR markers showed seventy polymorphic alleles, with an average of 5.83 alleles per locus. Additionally, the inter-population genetic diversity was 0.063. The nucleotide composition of the MT-CO1 sequences revealed clear variations between the two studied populations. Phylogenetic analyses indicated that the Red Sea samples were more versatile than the Mediterranean Sea samples. The results indicated that the mtDNA of S. rivulatus is very variable and a species-sensitive marker to detect possible genetic variations, which could be part of the eco-physiological adaptation and key to the success of the migrant S. rivulatus in the Mediterranean Sea.

Genetic diversity estimates for the Caenorhabditis Intervention Testing Program screening panel.

The Caenorhabditis Intervention Testing Program (CITP) was founded on the principle that compounds with positive effects across a genetically diverse test-set should have an increased probability of engaging conserved biochemical pathways with mammalian translational potential. To fulfill its mandate, the CITP uses a genetic diversity panel of Caenorhabditis strains for assaying longevity effects of candidate compounds. The panel comprises 22 strains from three different species, collected globally, to achieve inter-population genetic diversity. The three represented species, C. elegans, C. briggsae, and C. tropicalis, are all sequential hermaphrodites, which simplifies experimental procedures while maximizing intra-population homogeneity. Here, we present estimates of the genetic diversity encapsulated by the constituent strains in the panel based on their most recently published and publicly available whole-genome sequences, as well as two newly generated genomic data sets. We observed average genome-wide nucleotide diversity (π) within the C. elegans (1.2e-3), C. briggsae (7.5e-3), and C. tropicalis strains (2.6e-3) greater than estimates for human populations, and comparable to that found in mouse populations. Our analysis supports the assumption that the CITP screening panel encompasses broad genetic diversity, suggesting that lifespan-extending chemicals with efficacy across the panel should be enriched for interventions that function on conserved processes that are shared across genetic backgrounds. While the diversity panel was established by the CITP for studying longevity interventions, the panel may prove useful for the broader research community when seeking broadly efficacious interventions for any phenotype with potential genetic background effects.

تقييم معايير أدلة الحمض النووي لمواقع التكرار المترادفة القصيرة 24STR والحذف والإضافة على الكروموزوم Y لعينة من سكان جنوب المملكة العربية السعودية باستخدام طقم التكثير نوع GlobalFilter TM

The last three decades have seen rapid advances in the field of short tandem repeats (STRs) genotyping technology. Autosomal STRs have emerged as a powerful tool in forensic identification and paternity investigations. The indigenous population of Saudi Arabia is irregularly distributed and has historically been organized into geographically distinct groups or tribes of patrilineal descent. So far, there has been no detailed investigation of the southern region Saudi population to assist in the interpretation of DNA-based forensic evidence and in the construction of DNA database. The objective of this study is to investigate the genetic structure in 154 unrelated healthy Saudi subjects within three generations from the southern Saudi regions using a GlobalFiler™ PCR Amplification kit. Intra- and Inter-population genetic diversity as well as the forensic genetics parameters were analyzed. Our results showed that SE33 and TPOX loci were the most and the least polymorphic loci, respectively. The PIC, PE, TPI, Ho and He varied from 0.56116 (TPOX) to 0.94393 (SE33), 0.26638 (TPOX) to 0.83859 (SE33), 1.1875 (TPOX) to 6.33333 (SE33), 0.57894 (TPOX) to 0.92105 (SE33) and 0.6169 (TPOX) to 0.952 (SE33), respectively. The highest PM was observed for D22S1045 (0.223944) and the highest PD for SE33 (0.98935). The combined PD was 99.99999999% and the combined PM was equal to 3.19021E-25. Phylogenetic parameters showed that the southern region Saudi population had the closest genetic relationship with the Saudi, Emirati, Kuwaiti, and Bahraini populations. The study offers some important insights into the southern region Saudi population structure using GlobalFiler™ PCR Amplification kit.

A Meta-Analytical Investigation of the Gap between Measured and Predicted Inter-Population Genetic Diversity in Species of High Conservation Concern-The Case of the Critically Endangered European Mink Mustela lutreola L., 1761.

Although properly designed sampling in population genetic studies is of key importance for planning evidence-informed conservation measures, sampling strategies are rarely discussed. This is the case for the European mink Mustela lutreola, a critically endangered species. In order to address this problem, a meta-analysis aiming to examine the completeness of mtDNA haplotype sampling in recent studies of M. lutreola inter-population genetic diversity was conducted. The analysis was performed using the sample-size-based rarefaction and extrapolation sampling curve method for three populations—the Northeastern (Russia, Belarus and Estonia), the Western (France and Spain), and the Southeastern (Romania). The extrapolated values of the Shannon–Wiener index were determined, assuming full sample coverage. The gap between the measured and predicted inter-population genetic diversity was estimated, indicating that the identified level of sample coverage was the lowest for the NE population (87%), followed by the SE population (96%) and the W population (99%). A guide for sampling design and accounting for sampling uncertainty in future population genetic studies on European mink is provided. The relatively low sample coverage for the Russian population clearly indicates an urgent need to take conservation measures for European mink in this country.

Variability of some broomrape populations from China. Genotyping and determination of genetic polymorphism (II)

Genetic diversity within a population is reflected by variations in genetic material among individuals and can manifest at the phenotypic level through new characters or traits. The emergence of a large number of O. cumana races in a short period of time demonstrates that there are higher genetic variability in populations and a high ability to adapt in the face of environmental conditions. The aim of the research presented in this article was to study the intraand interpopulation genetic diversity and genetic relationships between individuals of three populations of O. cumana from different geographical regions of the People’s Republic of China based on molecular markers (ISSR and SSR). The high intrapopulation genetic variability calculated on the basis of the allelic diversity parameters and specific genetic diversity coefficients was revealed by SSR markers while as for the ISSR primers a high degree of genetic variations was found at the interpopulation level. UPGMA clustering and principal component analysis performed according to both sets of molecular markers allowed to devide all genotypes into 5 major groups for the degree of dissimilarity and level of aggression. This study is of interest in understanding the population genetic structure of the parasitic species of O. cumana from China and could contribute to the development of pathogen control durable strategies and effective sunflower breeding programs to broomrape resistance.

Taxonomic hypotheses and the biogeography of speciation in the Tiger Whiptail complex (Aspidoscelis tigris: Squamata, Teiidae)

Biodiversity in southwestern North America has a complex biogeographic history involving tectonism interspersed with climatic fluctuations. This yields a contemporary pattern replete with historic idiosyncrasies often difficult to interpret when viewed from through the lens of modern ecology. The Aspidoscelis tigris (Tiger Whiptail) complex (Squamata: Teiidae) is one such group in which taxonomic boundaries have been confounded by a series of complex biogeographic processes that have defined the evolution of the clade. To clarify this situation, we first generated multiple taxonomic hypotheses, which were subsequently tested using mitochondrial DNA sequences (ATPase 8 and 6) evaluated across 239 individuals representing five continental members of this complex. We then evaluated the manner by which our models parsed phylogenetic and biogeographic patterns. We found considerable variation among species ‘hypotheses,’ which we interpret as reflecting inflated levels of inter-population genetic divergence caused by historical demographic expansion and contraction cycles. Inter-specific boundaries with A. marmoratus juxtaposed topographically with the Cochise Filter Barrier that separates Sonoran and Chihuahuan deserts (interpreted herein as an example of ‘soft’ allopatry). Patterns of genetic divergence were consistent across the Cochise Filter Barrier, regardless of sample proximity. Surprisingly, this also held true for intraspecific comparisons that spanned the Colorado River. These in turn suggest geomorphic processes as a driver of speciation in the A. tigris complex, with intraspecific units governed by local demographic processes.

Assessing the genetic diversity of Myrsine umbellata (Primulaceae) in Brazilian Atlantic Forest remnants - an important step towards reforestation efforts

Abstract The investigation of genetic diversity in natural populations of species that show potential for use in reforestation programs is a key step in making management decisions. However, reforestation programs with native species in Brazil are still rarely based on a genetic understanding of the seed matrices used for seedling production. This is also the case for Myrsine umbellata, a dioecious shrub within the family Primulaceae that has been used in reforestation programs in Brazil, mainly due to its high production capacity of fruits attractive to the avifauna. The goal of this study was to measure intra- and interpopulational genetic diversity in natural populations of M. umbellata in six forest remnants of the Atlantic Forest using ISSR markers. The results revealed that the intrapopulational genetic diversity was greater than the genetic diversity among the studied populations. For this reason, the cultivation of seedlings from seeds obtained in more than one population seems the most appropriate strategy for reforestation purposes. Even though the most isolated populations are also the ones with highest genetic structure, all populations of M. umbellata included in this study revealed to be an important germplasm bank conserved in situ.

Structure and genetic diversity of Theobroma speciosum (Malvaceae) and implications for Brazilian Amazon conservation

Abstract The genetic diversity of Theobroma speciosum is important because its use in breeding programs, once the species is closely related to species of great economic value such as Theobroma cacao (cocoa) and Theobroma grandiflorum (cupuaçu). Thus, the objective of this work is to characterize the intra and interpopulational genetic diversity of Theobroma speciosum in natural populations in the Brazilian Amazon. Ninety individuals of T. speciosum from four populations localized in different states of legal Amazon were selected and genotyped. The data were obtained by fluorescence microsatellite analysis and the number of alleles, number of private alleles, fixation index, observed and expected heterozygosity were analyzed. Bayesian analysis, AMOVA and PCOa were used to reveal the molecular genetic structure of the populations, using the programs Structure and GenAIEx 6.5, respectively. All populations studied present great levels of gene diversity, although, there was a greater similarity among the AUR, API and MAC populations, while RBC population presented higher heterozygosity and less inbreeding than the others, becoming a possible refuge area in the Amazon, and the most important population for T. speciosum conservation.

تنوع ژنتیکی در میان جوامع گونههای گز با استفاده از نشانگر مولکولی CDDP

سرده Tamarix به دلیل عدم قطعیت تعداد گونه‌ها، پراکنش و اهمیت اکولوژیکی در ایران، یکی از مهم‌ترین موضوعات در رده‌بندی تیره گز است. در این مطالعه، تنوع ژنتیکی و روابط خانوادگی 34 فرد از 8 جمعیت از 3 گونه Tamarix در استان اصفهان مورد بررسی قرار گرفت. ده آغازگر از نشانگر مولکولی CDDP برای بررسی تنوع ژنتیکی این سرده استفاده شد. 125 باند از ده آغازگر ایجاد شد، که از این تعداد 102 (16/80 درصد) چند شکلی بودند. آنالیز خوشه‌ای جمعیت‌ها را به سه گروه مجزا دسته‌بندی کرد. جریان بالای ژنی در میان گونه‌های Tamarix با استفاده از تجزیه و تحلیل PCoA تنوع زیادی در بین سه گونه Tamarix نشان داد، به طوری که نمونه‌های گونه‌های مختلف با هم گروه‌بندی شدند. تجزیه واریانس مولکولی نشان داد که تنوع ژنتیکی بین جمعیت (90٪) بیشتر از تنوع ژنتیکی درون جمعیت (10٪) است. بالاترین میانگین تنوع ژنتیکی نای (H) و شاخص تنوع شانون (I) در جمعیت حبیب‌آباد مشاهده شد. تجزیه و تحلیل داده‌ها نشان داد که صفات ریخت‌شناختی و داده‌های توالی DNA در سرده Tamarix کاملا با هم ارتباط ندارند، که می‌تواند با وجود تعداد زیاد دورگه‌ بین گونه‌ها و عدم تمایز ژنتیکی بین گونه‌های مورد مطالعه توجیه شود.

Inter-population genetic diversity of cattle of the Kazakhstan population of Santa Gertrude Breed of Zhetysu type by microsatellite DNA

Analysis of the studied parameters of the population and genetic structure the cattle of Zhetysu type of Santa Gertrude breed has confirmed the presence of poorly differentiated subpopulations of animals in the southern and southeastern regions of Kazakhstan. The population and genetic structure of Zhetysu type of Santa Gertrude breed shows the differentiation of the population as a whole. The total number of alleles found in 11 microsatellite loci made up 135 including 121 – informative alleles, 90.72 – effective, and 14 – private ones. The average expected heterozygosity levels range from 0.7997 to 0.9117. According to Fis coefficient (individual fixation index), an excess of heterozygotes was found at TGLA53, ETH10, TGLA122, INRA23 and BM1824 loci. In other loci, a deficiency of heterizygotes is observed. The inbreeding coefficient Fst (subpopulation fixation index) made up 0.0094 which indicates the subdivision of the population (χ2 = 34.30, df = 1, significance level α < 0.001).

Genetic variability in Ruditapes decussatus clam combined with Perkinsus infection level to support founder population selection for a breeding program.

Clam farmers worldwide face several challenges, including irregular seed supply and high mortalities due to pathogenic organisms such as Perkinsus olseni. In Europe, there is a high unmet consumer demand for native clam species such as Ruditapes decussatus. The high market value of R. decussatus makes the culture of this species potentially more attractive than that culture of the alien species Ruditapes philippinarum. Thus, there is a market opportunity in breeding and producing R. decussatus at an industrial scale. A selective breeding program to improve R. decussatus performance will be carried out in Portugal; and the first critical step to develop such a breeding program is the establishment of a founder population. In this study, intra- and interpopulation genetic diversity was assessed using 13 microsatellite markers in eight natural beds located in Portugal, Spain and Italy. Also, allele and genotypic frequencies of each microsatellite locus were assessed discriminating between clams infected and non-infected by P. olseni. All locations showed similar values for several genetic diversity parameters. Analyses of population differentiation (FST, Bayesian clustering and AMOVAs) revealed five genetically differentiated regions: Rías Altas and Rías Baixas (NW Spain), North/Central Coast of Portugal, Gulf of Cadiz and Adriatic Sea. Significant differences in the allelic and genotypic frequency distribution between infected clams and non-infected ones at four microsatellite loci are reported suggesting that resistance to the disease could have a genetic basis. Moreover, a positive or negative relationship between the frequency of certain alleles and the parasite infection was inferred. Further studies should confirm the potential use of those alleles as genetic markers for P. olseni infection. Integrating results of genetic diversity within and between populations and Perkinsus infection levels, a founder population for a R. decussatus breeding program is proposed, composed by individuals from Barallobre (Rías Altas), Pontevedra or Cangas (Rías Baixas), Óbidos (North/Central Coast of Portugal), Algarve (Gulf of Cadiz) and Venice (Adriatic Sea).