Distribution Of Genetic Variation Research Articles

Distribution of genetic variability in mature and progeny populations of Abies alba Mill. from the Polish Western and Eastern Carpathians

This study aimed to compare patterns in the genetic structure of 27 mature stands and the natural regeneration of A. alba in the Eastern and Western Carpathians within the introgression zone of two refugial lineages from the Apennine and Balkan peninsulas. The distribution of the genetic diversity of fir stands was analysed using paternally inherited chloroplast DNA and five nuclear dominant inter simple sequence repeat markers (ISSRs). The study showed that the Balkan haplotype prevailed in both parental and progeny populations, and this haplotype was found in many mature Eastern Carpathian stands. Relatively high levels of genetic diversity were found in the mature stands (effective number of alleles Ne = 1.517, Shannon index I = 0.436, expected heterozygosity He = 0.295) and progeny (Ne = 1.515, I = 0.436 and He = 0.294) of silver fir. The analysis of molecular variance (AMOVA) revealed slight differences among the mature fir stands from the Western and Eastern Carpathians, with a value of 1.1%. According to principal coordinates analysis (PCoA) and STRUCTURE analyses, the populations, including stands of mature and progeny trees, were genetically separated into two groups. Slight genetic differences between the mature and progeny populations in the Polish Carpathians indicate sound gene pool transmission, which is essential for creating new selection and breeding programmes.

Assessment of genetic and morphological differentiation among populations of the Diederik Cuckoo Chrysococcyx caprius

The Diederik Cuckoo Chrysococcyx caprius is an African species widely distributed south of the Sahara, which migrates seasonally between breeding and nonbreeding sites. It is currently unknown whether the species consists of a single panmictic population or if it is genetically structured. To investigate this, we analysed sequence variation in three mitochondrial and two nuclear gene regions in combination with morphological measurements in specimens from four localities. Phylogenetic relationships were estimated using maximum-likelihood methods and included samples of Klaas’s Cuckoo Chrysococcyx klaas, Red-chested Cuckoo Cuculus solitarius, and African Cuckoo Cuculus gularis. Haplotype networks and analysis of molecular variance were used to characterise the spatial distribution of genetic diversity. A principal component analysis was performed to investigate morphological variation among localities. Molecular analysis identified two divergent mitochondrial lineages, which were found to occur in sympatry in one South African locality (Limpopo Province). The magnitude of divergence between versus within these lineages was low (0.4–1%) yet significant (F ST: 0.84–0.88). Lack of apparent phylogeographic structure provides support for the absence of physical barriers to gene flow in this species. The divergent mitochondrial lineages did not differ in morphological measurements. The emergence and persistence of shallow mitochondrial divergence among sympatric lineages in the Diederik Cuckoo could be linked to maternal divergence in host selection of these brood parasites — a hypothesis requiring additional data to be tested.

Oceanographic connectivity explains the intra-specific diversity of mangrove forests at global scales

The distribution of mangrove intra-specific biodiversity can be structured by historical demographic processes that enhance or limit effective population sizes. Oceanographic connectivity (OC) may further structure intra-specific biodiversity by preserving or diluting the genetic signatures of historical changes. Despite its relevance for biogeography and evolution, the role of oceanographic connectivity in structuring the distribution of mangrove's genetic diversity has not been addressed at global scale. Here we ask whether connectivity mediated by ocean currents explains the intra-specific diversity of mangroves. A comprehensive dataset of population genetic differentiation was compiled from the literature. Multigenerational connectivity and population centrality indices were estimated with biophysical modeling coupled with network analyses. The variability explained in genetic differentiation was tested with competitive regression models built upon classical isolation-by-distance (IBD) models considering geographic distance. We show that oceanographic connectivity can explain the genetic differentiation of mangrove populations regardless of the species, region, and genetic marker (significant regression models in 95% of cases, with an average R-square of 0.44 ± 0.23 and Person's correlation of 0.65 ± 0.17), systematically improving IBD models. Centrality indices, providing information on important stepping-stone sites between biogeographic regions, were also important in explaining differentiation (R-square improvement of 0.06 ± 0.07, up to 0.42). Wefurther show that ocean currents produce skewed dispersal kernels for mangroves, highlighting the role of rare long-distance dispersal events responsible for historical settlements. Overall, we demonstrate the role of oceanographic connectivity in structuring mangrove intra-specific diversity. Our findings are critical for mangroves' biogeography and evolution, but also for management strategies considering climate change and genetic biodiversity conservation.

Conservation Genetics of the Critically Endangered Southern River Terrapin (Batagur affinis) in Malaysia: Genetic Diversity and Novel Subspecies Distribution Ranges.

A population genetics study was carried out on the Southern River terrapin (Batagur affinis) from four places in Peninsular Malaysia: Pasir Gajah, Kemaman (KE), Terengganu; Bukit Pinang (BP), Kedah; Bota Kanan (BK), Perak; and Bukit Paloh, Kuala Berang (KB), Terengganu. The goal of this study is to identify genetic differences in two subspecies of B. affinis in Malaysia. No previous reports were available on the genetic diversity, phylogenetic relationships and matrilineal hereditary structure of these terrapin populations in Malaysia. The sequencing identified 46 single nucleotide polymorphisms that defined six mitochondrial haplotypes in the Southern River terrapins. Tajima's D test and Fu's Fs neutrality tests were performed to evaluate the signatures of recent historical demographic events. Based on the tests, the B. affinis edwardmolli was newly subspecies identified in the west coast-northern region of Kedah state. In addition, the B. affinis edwardmolli in Bukit Paloh, Kuala Berang (KB), Terengganu (Population 4), was shown to have a single maternal lineage compared to other populations. Low genetic diversity, but significant genetic differences, were detected among the studied Southern River terrapin populations.

A clue to the evolutionary history of modern East Asian flora: Insights from phylogeography and diterpenoid alkaloid distribution pattern of the Spiraea japonica complex

Each subkingdom of East Asian flora (EAF) has a unique evolutionary history, but which has rarely been described based on phylogeographic studies of EAF species. The Spiraea japonica L. complex, which is widespread in East Asia (EA), has received considerable attention because of the presence of diterpenoid alkaloids (DAs). It provides a proxy for understanding the genetic diversity and DA distribution patterns of species under various environmental conditions associated with the geological background in EA. In the present study, the plastome and chloroplast/nuclear DNA of 71 populations belonging to the S. japonica complex and its congeners were sequenced, combined with DA identification, environmental analyses, and ecological niche modelling, to investigate their phylogenetic relationships, genetic and DAs distribution patterns, biogeography, and demographic dynamics. An “ampliative” S. japonica complex was put forward, comprising all species of Sect. Calospira Ser. Japonicae, of which three evolutionary units carrying their respective unique types of DAs were identified and associated with the regionalization of EAF (referring to the Hengduan Mountains, central China, and east China). Moreover, a transition belt in central China with its biogeographic significance was revealed by genetic and DA distribution patterns from the perspective of ecological adaptation. The origin and onset differentiation of the “ampliative” S. japonica complex was estimated in the early Miocene (22.01/19.44 Ma). The formation of Japanese populations (6.75 Ma) was facilitated by the land bridge, which subsequently had a fairly stable demographic history. The populations in east China have undergone a founder effect after the Last Glacial Maximum, which may have been promoted by the expansion potential of polyploidization. Overall, the in-situ origin and diversification of the “ampliative” S. japonica complex since the early Miocene is a vertical section of the formation and development of modern EAF and was shaped by the geological history of each subkingdom.

Metavirome Analysis Reveals a High Prevalence of Porcine Hemagglutination Encephalomyelitis Virus in Clinically Healthy Pigs in China.

Six swine coronaviruses (SCoVs), which include porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine hemagglutination encephalomyelitis virus (PHEV), porcine respiratory coronavirus (PRCV), swine acute diarrhea syndrome coronavirus (SADS-CoV), and porcine delta coronavirus (PDCoV), have been reported as infecting and causing serious diseases in pigs. To investigate the genetic diversity and spatial distribution of SCoVs in clinically healthy pigs in China, we collected 6400 nasal swabs and 1245 serum samples from clinically healthy pigs at slaughterhouses in 13 provinces in 2017 and pooled them into 17 libraries by type and region for next-generation sequencing (NGS) and metavirome analyses. In total, we identified five species of SCoVs, including PEDV, PDCoV, PHEV, PRCV, and TGEV. Strikingly, PHEV was detected from all the samples in high abundance and its genome sequences accounted for 75.28% of all coronaviruses, while those belonging to TGEV (including PRCV), PEDV, and PDCoV were 20.4%, 2.66%, and 2.37%, respectively. The phylogenetic analysis showed that two lineages of PHEV have been circulating in pig populations in China. We also recognized two PRCVs which lack 672 nucleotides at the N-terminus of the S gene compared with that of TGEV. Together, we disclose preliminarily the genetic diversities of SCoVs in clinically healthy pigs in China and provide new insights into two SCoVs, PHEV and PRCV, that have been somewhat overlooked in previous studies in China.

Historical Landscape Evolution Shaped the Phylogeography and Population History of the Cyprinid Fishes of Acrossocheilus (Cypriniformes: Cyprinidae) According to Mitochondrial DNA in Zhejiang Province, China

Geological events and landscape features, as well as changes in the climate during the Pliocene period, have shaped the distribution of genetic diversity and demographic history of freshwater fish in mainland China. In this study, we investigated the phylogeny and population genetic structure of Acrossocheilus species (A. fasciatus, A. kreyenbergii and A. wenchowensis) in the Zhejiang region by the mitochondrial cytochrome b (cyt-b) and control (D-loop) region s. Mitochondrial phylogenetic analysis revealed three major lineages (lineages A, B and C), which may represent A. fasciatus, A. wenchowensis and A. kreyenbergii, respectively. Our results revealed that A. fasciatus and A. wenchowensis diverged from A. kreyenbergii in the Zhejiang region. The uplift of the Wuyi Mountains and the Xianxia Mountains served as an important geographic barrier in the diversification of the three Acrossocheilus species. The most recent common ancestors (TMRCAs) of the three lineages and lineages A + B were dated to 1.859 and 1.614 myr, respectively. Our results indicate that the effective population sizes of A. fasciatus and A. wenchowensis remained constant from the past to the present, as supported by ABC analysis. For conservation and protection, a strategy is required because of their genetic uniqueness, and we suggest that the two regions divided by the Xianxia Mountains be regarded as different management units (Mus), conforming to the major zoological regions of the Zhejiang region.

Genetic Diversity and Demographic Evolution Using <I>SRY </I>Gene Polymorphism in Four Lineages of Ladoum Sheep in Senegal

Knowledge of spatial and temporal distribution of genetic diversity within and between populations is a crucial step for establishing strategies management of Animal genetic resources. This study aims to contribute to a better understanding of the genetic structure of local sheep breeds. Specifically, it will characterize the genetic diversity, differentiation and evolution of the <I>SRY </I>gene in four main lineages of Ladoum sheep in Senegal. After alignments and corrections, a total of 42 sequences were used for analysis of <I>SRY</I> genetic diversity and demographic evolution. The standard indices of genetic diversity, genetic differenciation, analyses of hierarchical molecular variance (AMOVA) and demographic tests were compute. Analysis of genetic variability parameters in the overall population revealed a low level of polymorphism in the <I>SRY </I>gene. Haplotypic diversity is much higher than the average nucleotide divergence between all pairs of haplotypes. The genetic distances, as well as the values of the genetic differentiation factor beetween lineages, reveal two genetic groups; one made up of the individuals of “Birahim” and the other, grouping the three lineages individuals. Differences in frequencies of essential proteins for a multitude of functions in the body are observed between the "Birahim" lineage and the others. The comparative trends in genetic diversity indices, the shape of the mismatch distribution curves, demographic indices and demogenetic tests show a rapid and recent expansion population from an ancestral small size. The Z-test analysis of selection revealed that <I>SRY </I>gene is under selection. Unlike “Batling” who is under negative selection, "Birahim" and "Gorgui" are under positive selection. This study has made a significant contribution to understanding the genetic structure of the Ladoum raised in Senegal.

Pilot Study on the Geographical Mapping of Genetic Diversity among European Chestnut (Castanea sativa Mill.) Cultivars in Southern Italy.

Knowledge of the spatial distribution of European chestnut (Castanea sativa Mill.) cultivar diversity is essential for managing and conserving the genetic resources of this fruit tree species in Southern Italy. To this goal, the present work investigated the feasibility of mapping, through spatial representation, the distribution of genetic diversity of traditional chestnut varieties in the area of the Roccamonfina Regional Park in the Campania Region. After Principal Coordinates Analysis (PCoA) of molecular-genetic data, chestnuts formed varietal groups in a leopard spot on PCoA plots with a relatively high degree of genetic diversity. Successively, a Geographic Information System (GIS) tool utilized these molecular-genetic data to create a genetic divergence surface by geospatial interpolation on the geographic map of the Regional Park corresponding to each chestnut variety. The regions containing more biodiversity richness resulted in differentially colored from those containing cultivars less genetically distant from each other; thus, the area in study was consistently colored according to the allelic richness as evaluated by molecular-genetic markers. The combined use of tools for molecular and spatial analysis allowed for drafting genetic landscapes with the aim of extracting useful information for the safeguarding of the chestnut biodiversity at risk.

Ecological, Genetic, and Phylogenetic Aspects of YFV 2017-2019 Spread in Rio de Janeiro State.

In Brazil, a yellow fever (YF) outbreak was reported in areas considered YF-free for decades. The low vaccination coverage and the increasing forest fragmentation, with the wide distribution of vector mosquitoes, have been related to yellow fever virus (YFV) transmission beyond endemic areas since 2016. Aiming to elucidate the molecular and phylogenetic aspects of YFV spread on a local scale, we generated 43 new YFV genomes sampled from humans, non-human primates (NHP), and primarily, mosquitoes from highly heterogenic areas in 15 localities from Rio de Janeiro (RJ) state during the YFV 2016-2019 outbreak in southeast Brazil. Our analysis revealed that the genetic diversity and spatial distribution of the sylvatic transmission of YFV in RJ originated from at least two introductions and followed two chains of dissemination, here named the YFV RJ-I and YFV RJ-II clades. They moved with similar dispersal speeds from the north to the south of the RJ state in parallel directions, separated by the Serra do Mar Mountain chain, with YFV RJ-I invading the north coast of São Paulo state. The YFV RJ-I clade showed a more significant heterogeneity across the entire polyprotein. The YFV RJ-II clade, with only two amino acid polymorphisms, mapped at NS1 (I1086V), present only in mosquitoes at the same locality and NS4A (I2176V), shared by all YFV clade RJ-II, suggests a recent clustering of YFV isolates collected from different hosts. Our analyses strengthen the role of surveillance, genomic analyses of YVF isolated from other hosts, and environmental studies into the strategies to forecast, control, and prevent yellow fever outbreaks.

Genetic Diversity of Five Broadleaved Tree Species and Its Spatial Distribution in Self-Regenerating Stands

European forest ecosystems are currently subject to various disturbances and shifts in land-use legacies. To be able to forecast the trends and consequences of the changes in genetic diversity following these disturbances, it is of crucial importance to understand the genetic dynamics of natural tree populations. The present study aimed at determining the extent and spatial distribution of genetic diversity in five common broadleaved tree species in Lithuania in both mature (putatively maternal) stands and in natural regeneration (juveniles) of the respective species. The genetic diversity of Quercus robur, Betula pendula, Populus tremula, Alnus glutinosa, and Fraxinus excelsior was assessed using eight nuclear microsatellite loci for each species; 417 samples of regenerating juveniles and 141 samples of putatively maternal trees were analyzed in total. The investigated populations of self-regenerating Q. robur, B. pendula, A. glutinosa, and F. excelsior juveniles showed spatially random genetic structures, while P. tremula regenerated mostly via root suckers and formed clonal groups. The genetic diversity in regenerating juveniles of all species was as high as in putatively maternal stands. The detection of adequate (substantial) genetic diversity in the studied regenerating populations of these five broadleaved tree species suggests that in Lithuania these species have a good potential to adapt to changing environmental conditions.

Study on the mycorrhizal structure of common plants and rhizosphere AMF diversity of different plant communities in Central Province, Mongolia

With the dual destruction cased by man-made activities and natural causes, the biodiversity and ecosystem function of the prairie are reducing rapidly, which are manifest in such phenomenon as grassland desertification, sharp reduction in wetland, soil quality degradation, erosion of soil by wind, rain and watersheds. This condition restricts the development level of Mongolia's financial status and production forces, and so the protection and utilization of biodiversity resources are extremely important and harbor no delay. Arbuscular mycorrhizal fungi (AMF) has a broad distribution and species diversity, it also has very important functions of maintaining material circulation in ecosystems, improving ecosystem productivity, and ensuring ecological restoration. We selected different plant communities and the common plants in the Tuv aimag (Central province) of Mongolia to study the correlation between species diversity, genetic diversity and AM fungi distribution with physical and chemical properties of soil.

Patterns of Genetic And Epigenetic Diversity Across A Range Expansion in The White-Footed Mouse (Peromyscus Leucopus).

Populations at the leading front of a range expansion must rapidly adapt to novel conditions. Increased epigenetic diversity has been hypothesized to facilitate adaptation and population persistence via non-genetic phenotypic variation, especially if there is reduced genetic diversity when populations expand (i.e., epigenetic diversity compensates for low genetic diversity). In this study, we use the spatial distribution of genetic and epigenetic diversity to test this hypothesis in populations of the white-footed mouse (Peromyscus leucopus) sampled across a purported recent range expansion gradient. We found mixed support for the epigenetic compensation hypothesis and a lack of support for expectations for expansion populations of mice at the range edge, which likely reflects a complex history of expansion in white-footed mice in the Upper Peninsula of Michigan. Specifically, epigenetic diversity was not increased in the population at the purported edge of the range expansion in comparison to the other expansion populations. However, input from an additional ancestral source populations may have increased genetic diversity at this range edge population, counteracting the expected genetic consequences of expansion, as well as reducing the benefit of increased epigenetic diversity at the range edge. Future work will expand the focal populations to include expansion areas with a single founding lineage to test for the robustness of a general trend that supports the hypothesized compensation of reduced genetic diversity by epigenetic variation observed in the expansion population that was founded from a single historical source.

Phylogeography within the Peromyscus maniculatus species group: Understanding past distribution of genetic diversity and areas of refugia in western North America

The effects of anthropogenic climate change on biodiversity have been recognized on every continent, ocean, and across different taxonomic groups. Here, we study the range dynamics and demography of a cosmopolitan species: the deer mouse, Peromyscus maniculatus. We generated a multilocus SNP dataset using the ddRADseq protocol for 218 individuals across the geographic range within three western North American lineages of this species group. We evaluated population structure using several methods and explored the correlation between geographic and genetic distances. We modeled the demographic history using a site frequency spectrum approach and used a machine learning algorithm to infer current and past (Last Glacial Maximum; LGM) environmental suitability. Lastly, we explored the origin of population expansion for the identified lineages. The genome-wide SNP dataset was able to identify-three regionally distinct groups— 1) P. m. gambelii (southern California); 2) P. keeni (Pacific Northwest); 3) P. m. sonoriensis (a broad population spanning the Pacific Northwest through central California and across the Rocky Mountains into the Great Plains). Demographic analysis indicated the splits between the three populations occurred within the last 500 thousand years, with one very recent (late Holocene) split. Ecological niche models for each of these lineages predicted suitable environment present throughout their known ranges for current conditions, and a severe reduction of northern habitat in the past. The deer mouse has responded to past climate changes by expanding its range during interglacial periods and contracting its range during glacial periods leading to strong population differentiation. But lower magnitude climate change or other processes within the Holocene interglacial period led to population differentiation as well, which is likely still ongoing today given the substantial anthropogenic climate change and other landscape transformations caused by humans during the Anthropocene. By understanding the historical processes that led to the contemporary geographic distribution of biodiversity, we can determine the relative importance of different factors that shape biodiversity, now and into the future.

Genetic Diversity and Geographic Distribution of Cucurbit-Infecting Begomoviruses in the Philippines.

Cucurbits are important economic crops worldwide. However, the cucurbit leaf curl disease (CuLCD), caused by whitefly-transmitted begomoviruses constrains their production. In Southeast Asia, three major begomoviruses, Tomato leaf curl New Delhi virus (ToLCNDV), Squash leaf curl China virus (SLCCNV) and Squash leaf curl Philippines virus (SLCuPV) are associated with CuLCD. SLCuPV and SLCCNV were identified in Luzon, the Philippines. Here, the genetic diversity and geographic distribution of CuLCD-associated begomoviruses in the Philippines were studied based on 103 begomovirus detected out of 249 cucurbit samples collected from 60 locations throughout the country in 2018 and 2019. The presence of SLCCNV and SLCuPV throughout the Philippines were confirmed by begomovirus PCR detection and viral DNA sequence analysis. SLCuPV was determined as a predominant CuLCD-associated begomovirus and grouped into two strains. Interestingly, SLCCNV was detected in pumpkin and bottle gourd without associated viral DNA-B and mixed-infected with SLCuPV. Furthermore, the pathogenicity of selected isolates of SLCCNV and SLCuPV was confirmed. The results provide virus genetic diversity associated with CuLCD for further disease management, especially in developing the disease-resistant cultivars in the Philippines as well as Southeast Asia.

Molecular detection and phylogenetic analysis of lymphocytic choriomeningitis virus in ticks in Jilin Province, northeastern China.

Lymphocytic choriomeningitis virus (LCMV) is a neglected rodent-borne zoonotic virus in the genus Mammarenavirus and family Arenaviridae, that can cause aseptic meningitis in humans. A recent study identified infectious LCMV in ticks in northeastern (NE) China. To explore the distribution of LCMV, we determined the prevalence and genetically characterized LCMV in ticks in Jilin Province, NE China. Ticks collected in Huadian, Dunhua, and Jiaohe were pooled and LCMV was detected using reverse transcription polymerase chain reaction. The complete genomes of the LCMV-positive pools were amplified and used for phylogenetic analysis. A total of 1679 questing and engorged ticks were collected and divided into 170 pools, including Ixodes persulcatus (5%), Dermacentor silvarum (89%), and Haemaphysalis japonica (6%). Twenty-four pools of D. silvarum (14.9%, 95% CI:9.5-22.3) and three pools of H. japonica (36.3%, 95% CI:9.8-99.5) collected from cattle were LCMV-positive. No I. persulcatus pools were identified as LCMV-positive. Two complete genome sequences (strains JL-DH01 and JL-DH02) were successfully amplified. They had nucleotide identities of 96.4-99.8% with strains JX31, JX14, DH46, and JX4 identified in ticks from Jilin Province. Phylogenetic analysis indicated that JL-DH01 and JL-DH02 clustered with Jilin strains in the same branch and belonged to genotype I. The findings add to the knowledge of the genetic diversity and geographical distribution of LCMV in ticks in NE China.

Genetic Characterization of DH13M98, Umatilla Virus, Isolated from Culex tritaeniorhynchus Giles in Yunnan Province, China

Background: In August 2013, a virus strain (DH13M98) was isolated from Culex tritaeniorhynchus Giles collected in Mangshi, the southwestern border area of Yunnan Province, China. The virus replicated and caused cytopathic effects (CPE) in Aedes albopictus (C6/36) cells, but not in baby hamster Syrian kidney (BHK-21) cells. Materials and Methods: Agarose gel electrophoresis (AGE) analysis revealed that the DH13M98 virus was a 10-segment double-stranded RNA (dsRNA) virus, with a "1-1-1-2-1-1-2-1" pattern. The full genome of the DH13M98 virus was sequenced by full-length amplification of complementary DNAs (FLAC). Results: Phylogenetic analysis of the viral RNA-dependent RNA polymerase (Pol), major subcore-shell (T2), and major core-surface (T13) protein showed that DH13M98 clustered with Umatilla virus (UMAV), and the amino acid (aa) sequences of DH13M98 shared more than 89.5% (Pol), 95% (T2), and 91.1% (T13) identity with UMAV. However, the aa identity of outer capsid protein one (OC1) of DH13M98 with other UMAV was 57.1-79.2%, suggesting that DH13M98 was UMAV, but distinct from other strains of UMAV from the United States, Japan, and Germany at OC1, and it may be a high variant strain of UMAV, even a new serotype. Conclusion: This is the first isolation of UMAV in China, which enriches the resources of virus species in China and provides new insights into the genetic diversity and geographical distribution of the virus.

Commerson’s dolphin population structure: evidence for female phylopatry and male dispersal

A key in species conservation is understanding the amount and distribution of genetic diversity and how environmental changes that occurred in the recent past may have influenced current patterns of population structure. Commerson’s dolphin, Cephalorhynchus commersonii, has two subspecies, one of which is endemic to South America (C. commersonii commersonii) and little is known about its population genetics. Our objective was to investigate the population genetics of this subspecies throughout its distribution. Using 70 skin samples and information available in GenBank, 308 mitochondrial DNA sequences and 28 species-specific microsatellites were analyzed. The species presented low genetic diversity when compared to other dolphin species, but was consistent with other species within the genus. Strong population structure based on mitochondrial DNA was exhibited throughout its entire distribution, a pattern consistent with female philopatry. However, this pattern was not detected when using microsatellites, suggesting male-mediated gene flow. Demographic tests suggested a population expansion beginning approximately 15,000 years ago, after the Last Glacial Maximum. In a climate change scenario, we recommended considering each sampling location as an independent population management unit in order to evaluate the impact of possible environmental changes on the distribution of genetic information within the species.

Distribution of Genetic Diversity in Beta patula Aiton Populations from Madeira Archipelago, Portugal

Beta patula Aiton is a crop wild relative (CWR) which belongs to the Gene Pool 1b and is considered a Critically Endangered species, and is present in very specific environments, such as the Desembarcadouro islet (DI) in Ponta de São Lourenço or Chão islet (CI) in the Desertas Islands. The ISOPlexis Center (University of Madeira) has been providing continuous support for its in situ conservation by keeping a management plan of wild populations and an ex situ conservation strategy through the storage of accessions in the ISOPlexis GeneBank. The present work intends to present the spatial distribution of genetic variability and diversity in these B. patula populations using eight polymorphic Simple Sequence Repeat (SSR) markers. The overall results lead to the identification of three spots with a high genetic diversity. CI with a small cluster of individuals shows a genetic footprint different from DI, having unique alleles present in its population. DI has two distinct areas: the western area, with a higher individual density but with a lower genetic diversity and higher allele fixation; and the central area, with a lower individual count but with a higher genetic diversity and with the presence of unique alleles. Despite some genetic differences, the comparison of the two islets’ DI and CI populations shows that they have more similarities than differences. Analysis of the Molecular Variance, based on the hierarchical cluster, showed a 9% diversity between populations, 68% among individuals, and 23% within individuals. This data will be used for the establishment of a protocol to monitor and manage B. patula genetic diversity under a genetic reserve, subsequently contributing to the European Genetic Reserve network implementation and the protection of this important CWR.

Haplogroup of the modern lines of hybrid pigs

The aim. The study was conducted to characterize the genetic diversity of hybrid pigs (Large White×Landrace)×Maxgro in Ukraine. Method. DNA isolation was performed from bristle samples using Chelex-100 ion exchange resin and epithelial tissue from the ear of pigs by the sorbent method. The results. The results of DNA typing of hybrid pigs (Large White×Landrace)×Maxgro from LLC "Hlobynskyi Svynocomplex" are presented. Using PCR-RFLP analysis of the polymorphism of the D-loop section, 7 mitochondrial haplotypes were determined – N, C, O, G, D, E, K. In the studied sample of pigs (n=50), the concentration of haplotypes as a percentage is determined. It was found that mitochondrial haplotypes C (24 %) were found to be characteristic of Landrace pigs, Hampshire, Wales, a wild pig (Ukraine, Poland, France); haplotype O (12%) – inherent in a wild pig and Landrace breed (Sweden); haplotype G (12 %) – peculiar to Wales breed, a wild pig (Italy, France); haplotype N (28%) is characteristic of the Large White breed of pigs, representatives are carriers of the Asian type. It is worth noting that the Asian haplotype N is characteristic of the Asian wild pig and Berkshire breed. The presented data on the hybridization of mitochondrial genomes of Asian and European origin are the basis for the creation of modern lines of hybrid pigs along the maternal line. Haplotype N refers to haplogroup A(D), and haplotypes C, O, G belong to haplogroup E. It is completely uncertain that haplotypes D (10 %), E (6 %), K (8 %) belong to haplogroup A(D). According to the results obtained, haplogroup E in hybrid pigs is dominant, however, it is haplogroup A that is the predecessor of haplogroup E. We assume opinions that pigs of the Large White breed with haplotype N, D, E, K – contain aboriginal genetic resources. Pigs with haplotype D, E, K – are the result of hybridization with European wild boars. Over time, this led to the almost complete disappearance of the primary Middle Eastern ancestors in the nuclear genomes of European domesticated pigs. The speculation that traditional seasonal cattle breeding, annual long-distance migrations that have occurred in the past, and commercial trade in nucleuses explain the observatory pattern of favorable gene flow among hybrid pigs. Conclusions. The results obtained during the study of the mitochondrial genome of hybrid pigs improved the understanding of matrilineal origin and phylogeographic model of distribution of genetic diversity of cross-border pig breeds (Large White×Landrace)×Maxgro in Ukraine. We came to the conclusion that natural selection acts very weakly on the single nucleotide polymorphism that led to the formation of the haplogroup of cross-border breeds of pigs that are found today. The obtained results of the study are evidence that European pig breeds consist of pigs with Asian and non-Asian mitochondria, some of which were formed from closely related maternal ancestors. The work was carried out with the support of the National Academy of Agrarian Sciences of Ukraine 31.01.00.07.F. "To study the pleiotropic effect of genes whose SNPs are used in markerassociated selection of pigs." SR No. 0121U109838. Key words: hybrid pigs, (Large White×Landrace)×Maxgro, mtDNA, D-loop, haplotype, haplogroup, PCR-PDRF.