Search

Characterizing the genetic diversity of a species is crucial for understanding the factors that influence its local dispersion and population dynamics. Additionally, it provides insights into local processes that may affect the distribution of other species. Lineus sanguineus (Rathke, 1799) is a widely distributed species commonly found on fouling fauna along rocky shores. This species can reproduce asexually by fissiparity, and its pilidium larva facilitates dispersal, similar to other heteronemerteans. The present study utilized a population genetics approach combined with Ecological Niche Modeling analysis to evaluate L. sanguineus populations along the Brazilian coast. We used sequences from two mtDNA regions, 16S ribosomal RNA (16SrRNA) and cytochrome c oxidase subunit 1 (COI), and one nuclear region, Internal Transcribed Spacer 1 (ITS-1), from 85 specimens sampled in nine locations. Genetic diversity analysis revealed greater genetic variation for the ITS-1 marker compared to mtDNA, as evidenced by higher intrapopulation diversity values. There was no clear geographic pattern, and the AMOVA analysis revealed low to moderate genetic structuring and high connectivity among sampled localities, with most of the genetic variation contained within populations. The pairwise FST results indicate high genetic structuring between the Northeast and localities along the South and Southeast of Atlantic coastlines. This pattern suggests that Brazilian oceanic currents play an important role in species connectivity. The paleodistribution pattern demonstrated that the colonization could have occured from the South to the Northeast of the continent. These results reinforce that sexual reproduction and larval dispersion play a vital role in the connectivity of these Southwest Atlantic populations and that oceanographic currents, rafting and artificial transport facilitate these processes. [ABSTRACT FROM AUTHOR]

Brachidontes variabilis (Krauss, 1848) is a common small mussel widely distributed in the intertidal zone of southern China. Firstly, we characterized four complete mitochondrial genomes of B. variabilis from four populations (Wanning, Yangjiang, Zhangzhou, and Shanwei) in Chinese waters. This study was the first to sequence and discribe the mitochondrial genome of B. variabilis, which comprised of 2 ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs) and 12 protein-coding genes (PCGs, lacking atp8). And then three PCGs fragments, including cytochrome oxidase subunit I (cox1, 558 bp), NADH dehydrogenase subunit 5 (nad5, 754 bp), and NADH dehydrogenase subunit 4 (nad4, 879 bp), were utilized to investigate the population genetics and demography. The cox1, nad5 and nad4 fragments revealed 55, 81, and 103 haplotypes, respectively. Results indicated high genetic diversity within populations (Hd > 0.5, Pi > 0.005) and little genetic differentiation among populations (FST<0.05), suggesting frequent gene exchanges. Further, the neutrality test and Extended Bayesian skyline plots (EBSPs) suggested that the four populations underwent population expansion at 0.9–1.1 Ma during the Pleistocene. In summary, this study on the mitochondrial genomes and population genetics of B. variabilis provides insights into the evolutionary history and demographic dynamics of this species in southern China. [ABSTRACT FROM AUTHOR]

Reproductive interference is defined as an interspecific interaction that reduces fitness via mating processes. Although its ecological and evolutionary consequences have attracted much attention, how reproductive interference affects the population genetic structures of interacting species is still unclear. In flowering plants, recent studies found that self-pollination can mitigate the negative effects of reproductive interference. Selfing-biased seed production is expected to increase population-level inbreeding and the selfing rate, and limits gene flow via pollinator outcrossing among populations. We examined the population genetics of the mixed-mating annual herb Commelina communis f. ciliata, focusing on reproductive interference by the sympatric competing congener C. communis using microsatellite markers. First, we found that almost all C. c. f. ciliata populations had relatively high inbreeding coefficients. Then, comparing sympatric and allopatric populations, we found evidence that reproductive interference from a competing congener increased the inbreeding coefficient and selfing rate. Allopatric populations exhibit varied selfing rates while almost all sympatric populations exhibit extremely high selfing rates, suggesting that population selfing rates were also influenced by unexamined factors, such as pollinator limitation. Besides, our findings revealed that reproductive interference from a competing congener did not limit gene flow among populations. We present the first report on how reproductive interference affects the genetic aspects of populations. Our results suggested that the high selfing rate of C. c. f. ciliata promotes its sympatric distribution with C. communis, even in the presence of reproductive interference, although it is not clear whether reproductive interference directly causes the high selfing rate. [ABSTRACT FROM AUTHOR]

Whole genome sequences (WGS) of 185 North American Thoroughbred horses were compared to quantify the number and frequency of variants, diversity of mitotypes, and autosomal runs of homozygosity (ROH). Of the samples, 82 horses were born between 1965 and 1986 (Group 1); the remaining 103, selected to maximize pedigree diversity, were born between 2000 and 2020 (Group 2). Over 14.3 million autosomal variants were identified with 4.5–5.0 million found per horse. Mitochondrial sequences associated the North American Thoroughbreds with 9 of 17 clades previously identified among diverse breeds. Individual coefficients of inbreeding, estimated from ROH, averaged 0.266 (Group 1) and 0.283 (Group 2). When SNP arrays were simulated using subsets of WGS markers, the arrays over-estimated lengths of ROH. WGS-based estimates of inbreeding were highly correlated (r > 0.98) with SNP array-based estimates, but only moderately correlated (r = 0.40) with inbreeding based on 5-generation pedigrees. On average, Group 1 horses had more heterozygous variants (P < 0.001), more total variants (P < 0.001), and lower individual inbreeding (FROH; P < 0.001) than horses in Group 2. However, the distribution of numbers of variants, allele frequency, and extent of ROH overlapped among all horses such that it was not possible to identify the group of origin of any single horse using these measures. Consequently, the Thoroughbred population would be better monitored by investigating changes in specific variants, rather than relying on broad measures of diversity. The WGS for these 185 horses is publicly available for comparison to other populations and as a foundation for modeling changes in population structure, breeding practices, or the appearance of deleterious variants. [ABSTRACT FROM AUTHOR]

The Deccan mahseer, Tor khudree (Sykes 1839), belonging to family Cyprinidae is an important food and a game fish distributed in peninsular India. Due to overfishing and habitat destruction, the species is declared endangered and placed on the IUCN red list. Therefore, a well-designed conservation program may be essential to get this species protected in its natural habitat. We used a total of 152 samples from four rivers of peninsular India to assess the genetic diversity and structure of the mahseer using concatenated sequences of two mitochondrial genes, ATPase 6/8 (790 bp) and Cyt b (1000 bp). High haplotypic diversity was seen with 44 haplotypes. Individual gene wise haplotypes included 10 and 21 haplotypes for ATPase6/8 and Cyt b, respectively. AMOVA revealed most of the genetic variations (71.02%) to be within the populations. Significant genetic differentiation was observed between all population pairs, with FST values ranging from 0.121 to 0.372, with minimum between Tunga and Tungabhadra population and maximum between Tunga and Periyar population. Haplotype network showed one ancestral haplotype (TKACH04). Significant negative Fu's F and unimodal mismatch distribution suggested recent demographic expansion. The results of the present study would serve as a useful resource for further research on population genetics and conservation programs of the species. [ABSTRACT FROM AUTHOR]

Turkey oak (Quercus cerris L.) is one of the most ecologically and economically significant deciduous tree species in the Central and Southeast European regions. The species has long been known to exhibit high levels of genetic and phenotypic variation. Recent climate response predictions for Turkey oak suggest a significant distribution extension in Europe under climate change. Since Turkey oak has relative drought-tolerant behaviour, it is regarded as a potential alternative for other forest tree species during forestry climate adaptation efforts, not only in its native regions but also in Western Europe. For this reason, the survey of existing genetic variability, genetic resources, and adaptability of this species has great significance. Next-generation sequencing approaches, such as ddRAD-seq (Double digest restriction-site associated DNA sequencing), allow the attainment of high-resolution genome-wide single nucleotide polymorphisms (SNPs). This study provides the first highly variable genome-wide SNP data for Turkey oak generated by ddRAD-seq. The dataset comprises 17 607 de novo and 26 059 reference mapped SNPs for 88 individuals from eight populations, two from Bulgaria, one from Kosovo, and five from Hungary. Reference mapping was carried out by using cork oak's (Quercus suber L.) reference genome. The obtained high-resolution genome-wide markers are suitable for investigating selection and local adaptation and inferring genetic diversity, differentiation, and population structure. The dataset is accessible at: https://doi.org/10.5281/zenodo.8091252 [ABSTRACT FROM AUTHOR]

We investigated population genetics of the native tree species Acer velutinum Boiss., Fagus orientalis Lipsky, and Quercus castaneifolia C.A. Mey. in the Hyrcanian forests of northern Iran and also F. orientalis populations in the Euro-Siberian and Colchic subregions of northern Türkiye. We used the double-digest RADseq method and genotyped 90 populations and 1,589 individuals across the distribution range of the species. Genome-wide SNPs from 28 populations of A. velutinum, 32 populations of F. orientalis, and 30 Q. castaneifolia revealed higher genetic differentiation among A. velutinum populations than among F. orientalis and Q. castaneifolia. The global FST value was lowest for F. orientalis populations and highest for A. velutinum populations, while the global FIS value was negative for A. velutinum. Demographic history analysis revealed a bottleneck during the last glacial period (11,500—115,000 Kya) for the A. velutinum populations with reduced effective population size (Ne). All three species show multiple bottlenecks and reduced Ne during the Quaternary. Pronounced genetic divergence among A. velutinum populations in the Hyrcanian forests compared to the other two species suggests cryptic speciation. Conversely, F. orientalis and Q. castaneifolia populations showed low levels of genetic structure, suggesting that species-specific factors, such as pollen production and pollination efficiency, may have influenced the genetic patterns within these species in similar environments. The nucleotide diversity of F. orientalis populations in Iran is negatively correlated with altitude (p = 0.046). In contrast, A. velutinum populations show a significant correlation between nucleotide diversity and longitude (p = 0.008). Furthermore, the F. orientalis populations from Türkiye showed a distinct west–east genetic structure and were highly diverged from the Iranian F. orientalis populations. [ABSTRACT FROM AUTHOR]

Knowledge of the genetic diversity and population structure of species can facilitate conservation and guide management programs. However, the type of molecular markers used can affect estimates of genetic divergence and population structure. Here three types of molecular markers were used to estimate the genetic diversity and population structure of Euterpe edulis, a palm endemic to the Atlantic Forest and economically and ecologically important. The objective was to estimate the parameters of genetic diversity and population structure for two other types of molecular markers (SNP and SilicoDArT) in addition to the commonly used one (SSR) to the species. We used single nucleotide polymorphism (SNP), SilicoDArT, and microsatellite (SSR) markers in 138 E. edulis individuals sampled from 15 sites. Euterpe edulis individuals were grouped into 11 clusters using SNPs and SilicoDArT and six groups using SSR data. The SNP and SilicoDArT data showed less divergence between the individuals within each cluster in comparison to the results derived from the SSR data. The probability of reassigning individuals to their cluster of origin revealed an average association with the original clusters was 0.92 for SNPs (n = 100), 0.71 for SSR (n = 8), and 0.99 for SilicoDArT (n = 445). The genetic divergence is high among sites using SNP markers, whereas SSRs showed the largest genetic divergence is found within each site. The overall heterozygosity values for each site in the eight SSR (He = 0.69; Ho = 0.59) markers were almost four times higher than those values inferred using SNPs (data 7833 SNP, He = 0.15; Ho = 0.13; data 100 SNP, He = 0.14; Ho = 0.12). Within each site, we found low inbreeding rates using both markers (SNP and SSR). In addition, population structure analysis identified two strongly supported geographical groups, one northern and one southern Brazilian Atlantic Forest group, for both markers. This study contributes to the understanding of the population genetics and population structure of E. edulis and may have important implications for its conservation. In addition, our results suggest that SNP and SilicoDArT markers are more effective for evaluating population structure, but SSR is more capable of detecting diversity among individuals for this species. [ABSTRACT FROM AUTHOR]

The raccoon roundworm (Baylisascaris procyonis), a gastrointestinal nematode parasite of the raccoon (Procyon lotor), is the causative agent of a zoonotic disease that can cause severe neurological sequelae and even fatal cases. The parasite is now established in Europe and, while not present in all raccoon populations, it is currently expanding its range. Understanding the geographic distribution of the roundworm is a necessity for public health. Here, we report the first detections of the raccoon roundworm from Luxembourg. We used genetic techniques to test whether the roundworm originated from a distinct introduction event or entered the country by natural dispersal. We detected two roundworms in a raccoon that was road-killed in Echternach, northeastern Luxembourg. Furthermore, in a wildlife rescue centre, roundworms were detected in the latrine of an enclosure containing seven raccoons. Using different genetic techniques, we showed the Echternach roundworms to originate from the nearest German population, while the rescue centre roundworms were genetically distinct. By genotyping the host from a roundworm DNA extract, we identified a raccoon originating from southwest Luxembourg as the host of at least one roundworm. Roundworms are thus colonising Luxembourg both by natural dispersal and from an introduced population. The (potential) hosts all originated from the local population, suggesting that imported/introduced roundworms have already spread to the local raccoon population. Authorities should act as though the parasite is already widespread in the country, raising awareness among the public and individuals with occupational contact with raccoons. [ABSTRACT FROM AUTHOR]

Thyrinteina arnobia (Lepidoptera: Geometridae) is a native American species. Despite its historical importance as an insect pest in Eucalyptus plantations, more information is needed regarding the population diversity, demography, and climatic variables associated with its distribution in different regions of Brazil. We used a phylogeographic approach to infer the genetic diversity, genetic structure, and demographic parameters of T. arnobia. We also conducted an ecological niche modeling (ENM) to predict suitable areas for T. arnobia occurrence in Brazil and other countries worldwide. Although T. arnobia populations have low genetic diversity in Brazil, we identified mitochondrial haplogroups predominating in different Brazilian regions and high ФST and ФCT values in AMOVA, suggesting a low frequency of insect movement among these regions. These results indicate that outbreaks of T. arnobia in Eucalyptus areas in different regions of Brazil are associated with local or regional populations, with no significant contribution from long-distance dispersal from different regions or biomes, suggesting that pest management strategies would be implemented on a regional scale. In Brazil, the demographic and spatial expansion signals of T. arnobia seem to be associated with the history of geographical expansion of Eucalyptus plantations, a new sustainable host for this species. ENM indicated that isothermality and annual rainfall are critical climatic factors for the occurrence of T. arnobia in tropical and subtropical areas in the Americas. ENM also suggested that T. arnobia is a potential pest in Eucalyptus areas in all Brazilian territory and in regions from Africa, Asia, and Oceania. [ABSTRACT FROM AUTHOR]

The hypervariable region (HVR) in the control region of the mitochondrial DNA has frequently been used for population genetics and phylogeographic studies because of its highly variable nature. Although the HVR is beneficial for evaluating recent evolutionary history, including population demography, recent studies have implied the incidence of homoplasy in this region. To assess the accuracy of relying solely on the HVR for population genetics studies, molecular evolutionary analysis of the HVR, NADH-dehydrogenase subunit 2 (ND2), and cytochrome b genes were performed using 120 individuals of marbled flounder Pseudopleuronectes yokohamae. The HVR exhibited the highest genetic variability among the three regions, with sites showing high site-specific substitution rates. Considering the reticulate haplotype network structure and evolutionary linkages between regions, homoplastic mutations were indicated in the HVR in addition to ND2, underestimating genetic diversity. We found that homoplasy was less likely to affect coalescent-based demographic inferences in the population; however, there is still a potential risk of misinterpretation of population demography when solely using the HVR owing to its hypervariable nature. Collectively, we suggest analyzing other regions in addition to the HVR in fish population genetic research to improve accuracy and eliminate biases caused by homoplasy. [ABSTRACT FROM AUTHOR]

A total of 20 polymorphic microsatellites were developed and characterized for a potential aquaculture species, Chanos chanos, utilizing the comprehensive whole genome data of C. chanos obtained from the GenBank database (accession number: LR697106). Using the MIcroSAtellite (MISA) tool, potential microsatellite motifs were identified in the assembled contigs and unigenes and with the PRIMER 3 input software (Version 4.1.0), new primers were developed. The number of alleles per locus in C. chanos varied from 9 to 16, with observed heterozygosities ranging from 0.710 to 0.926, while the expected heterozygosities were within the range of 0.720 to 0.902. Among the 20 microsatellite loci, the majority exhibited PIC values > 0.75. Validation of these microsatellite markers proved that these markers can be used as a significant tool for analysing genetic differentiation as well genetic relationships among C. chanos. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether the sea acts as a geographical barrier to gene flow in Xylocopa frontalis. To achieve this, 90 female individuals from three geographic populations were analyzed. These populations were collected from the north coast of the state of São Paulo (Brazil) in mainland and insular areas. The genetic variability was assessed by sequencing two regions of the mitochondrial genome (COI and Cytb) and by genotyping 12 microsatellite loci. The results showed that there was no population genetic structure for both mitochondrial and nuclear markers, indicating a low rate of inbreeding. The analyses suggest that gene flow occurs between mainland and island populations mediated by both females and males. [ABSTRACT FROM AUTHOR]

Forest musk deer (Moschus berezovskii) is one of the most endangered medicinally important wild animals in the world. Forest musk deer farming is the main way of production of musk. However, the single provenance and lack of genetic information lead to reduced genetic diversity of forest musk deer. Therefore, more SSR markers need to be developed to identify forest musk deer germplasm. In this study, bone marrow derived mesenchymal cells were used to construct cDNA library for transcriptome sequencing. The datasets were de novo assembled and annotated. 9 polymorphic simple sequence repeat (SSR) markers were finally identified and used to detect population genetic diversity. 6.07 Gb clean data were generated using Illumina sequencing technology, and de novo assembled into 138,591 transcripts and 81,553 unigenes. 5,777 simple sequence repeats (SSRs) were identified, in which there were 578 repeating motif types, with mono-nucleotide and tri-nucleotides comprising 55.88% and 25.60%, respectively. 100 primer pairs were designed to validate amplification and polymorphism using DNA from fecal samples. 9 polymorphic SSRs were developed and used to detect population genetic diversity of 122 forest musk deer in 2 farms. The average number of alleles per locus varied from 4 to 15 (average = 8.3). The observed heterozygosity (HO) per locus ranged from 0.102 to 0.941, while the expected heterozygosity (HE) per locus was from 0.111 to 0.651. All loci deviated significantly from the Hardy–Weinberg equilibrium (p < 0.001). The polymorphism information content (PIC) of these loci varied from 0.108 to 0.619. 9 polymorphic SSR markers were developed in this research. These sites can be used for breeding planning and conservation of germplasm resources. [ABSTRACT FROM AUTHOR]

ITS sections, which are situated inside the ribosomal DNA operon, are recognized for their high levels of diversity and slow rate of evolution, which makes them important for plant phylogenetic studies. The objective of this work is to use the internal transcribed spacer (ITS) regions of 18 alfalfa (Medicago sativa) genotypes/varieties to determine their genetic relationships and to verify possible genetic markers for variety identification and classification. This has been done by validating the secondary structures of the ITS regions and observing the effects of the relationships among the lowest energy state, the total number of possible secondary structure hairpins, and (GC) content. The results indicated that the length of the ITS sequences varied between 426 and 629 nucleotides and that the G + C content of the ITS region varied between 46.6 and 50%. In this study, the analysis of molecular variance (AMOVA) was used to validate the effectiveness of configuration analysis and revealed that fluctuations in the data accounted for a substantial amount of the observed total variance. Moreover, 94 percent of the genotypes analyzed exhibited a significant degree of variety. This shows that a large fraction of the observed variation is likely attributable to genetic variables. Population four, comprising Bilensoy80, Emily, Quin, Vendor, and Felicia, had the highest degree of heterozygosity at 68.8%, whereas population two, including Gozlu1, Prosementi, Nimet and Local (Van), had the lowest level at 37.5%. The original Shannon's approach as an unbiased estimator employed in population genetics research validated the differences among alfalfa genotypes with the AMOVA analysis results of this study. Individual differences were found to be 59%, whereas population differences were found to be 41%. There have been a few ITS studies on Medicago sativa that have utilized ITS as a phylogenetic marker to estimate connections and define new taxonomic categories (e.g., tribes). However, our research also includes an analysis of the secondary structure of these sequences and the results of this study imply that ITS sequence and secondary structure data can be utilized to understand the intraspecific genetic makeup of different alfalfa varieties. [ABSTRACT FROM AUTHOR]

The tropical southwest Indian Ocean is a coral biodiversity hotspot, with remote reefs physically connected by larval dispersal through eddies and a complex set of equatorial and boundary currents. Based on multidecadal, 2 km resolution hydrodynamic and larval dispersal models that incorporate temporal variability in dispersal, we find that powerful zonal currents, current bifurcations, and geographic isolation act as leaky dispersal barriers, partitioning the southwest Indian Ocean into clusters of reefs that tend to consistently retain larvae, and therefore gene flow, over many generations. Whilst exceptionally remote, the Chagos Archipelago can broadcast (and receive) considerable numbers of larvae to (and from) reefs across the wider southwest Indian Ocean, most significantly exchanging larvae with the Inner Islands of Seychelles, but also the Mozambique Channel region. Considering multi-generational dispersal indicates that most coral populations in the southwest Indian Ocean are physically connected within a few hundred steps of dispersal. These results suggest that regional biogeography and population structure can be largely attributed to geologically recent patterns of larval dispersal, although some notable discrepancies indicate that palaeogeography and environmental suitability also play an important role. The model output and connectivity matrices are available in full and will provide useful physical context to regional biogeography and connectivity studies, as well as supporting marine spatial planning efforts. [ABSTRACT FROM AUTHOR]

Wildlife reintroduction is an important conservation tool for threatened species, yet identifying appropriate source populations poses a challenge. In particular, the possibility of outbreeding depression is cited as a constraint limiting the range of candidate source populations for translocation. When multiple source lineages are mixed during reintroduction, genetic monitoring is necessary to evaluate whether sources contribute equally to subsequent generations and whether they are interbreeding as expected. Moreover, statistical analysis of genetic data should account for complex life histories that might affect the timescale of admixture and genetic drift. Here, we use samples collected over a 23-year period and a stochastic age-structured model to analyze the genetic mixing process in reintroduced Brook Trout (Salvelinus fontinalis) populations in the Southern Appalachians. Each restored population was seeded with two to three source populations. Previous research inferred reproductive isolation between source populations leading to a proposal of splitting the species into multiple taxa. In contrast, we found patterns of ancestry that were consistent with random mating and no advantage for one source lineage over any other. Brook Trout from different source streams are mixing as expected in the restoration sites. This result does not support the hypothesis that Brook Trout in the Southern Appalachian Mountains includes several distinct species. Mixing different sources from the same watershed seems to be an effective way to increase genetic diversity of reintroduced populations while minimizing risk to source populations. [ABSTRACT FROM AUTHOR]

Wild species living in captivity are subject to loss of genetic diversity, inbreeding depression, and differentiation among populations. Only very few species have been under human care for centuries but have not been selectively bred, have free-ranging movements most of the time, and retain porous barriers to gene flow between wild and captive populations. Such captive populations are expected to retain high levels of genetic diversity and anthropogenic factors should result in a limited genetic differentiation from wild populations. Asian elephants have been trained and used by humans for at least 4000 years as war animals, mounts of kings and draught animals. In Myanmar and Laos, elephants are still being used for hauling timber in the forest while retaining traditional management practices including seasonal release, free mating and movement. However, habitat fragmentation, isolation and reduced gene flows are threatening both semi-captive and wild pools. We genotyped 167 semi-captive elephants from Laos and Myanmar using a panel of 11 microsatellite loci to estimate the genetic diversity and population structure. We found that elephants of both countries presented high levels of genetic diversity and a low degree of inbreeding, if any. This agrees with the expected high level of genetic diversity in semi-captive populations. We found a weak differentiation along a geographical gradient from southern Laos to northern Myanmar but no differentiation between wild-caught and captive-born pools. The potential value for conservation of a large population of semi-captive elephants has been recognized but the conservation community has yet to fully explore the potential role semi-captive elephants could play in maintaining gene flows. [ABSTRACT FROM AUTHOR]

Better knowledge of genetic relationships between the Fortymile caribou herd and its neighbors is needed for conservation decision-making in Canada. Here, we contribute the first fine-scale analysis of genetic population structure in nine contiguous caribou herds at the geographic boundaries between Barren-ground and Northern Mountain caribou, and at the Alaska-Yukon border. Using pairwise differentiation metrics, STRUCTURE, and discriminant analysis of principal components (DAPC) to analyze 15 microsatellite loci in 379 caribou, we found complex patterns of genetic differentiation. The Fortymile was the only herd assigned to more than one genetic cluster, indicative of its history as a larger herd whose range expansions and gene flow to other herds were likely important to maintaining diversity across a functioning genetic metapopulation. Some small herds (Chisana, Klaza, and White Mountains) were genetically distinct, while others (Hart River, Clear Creek, Mentasta) exhibited little differentiation from herds they occasionally overlap, including herds assigned to different conservation units (DUs). This genetic connectivity does not result from demographic connectivity, as episodic contact during rut, rather than herd switching, is the likely mechanism. Unusually, one small herd (White Mountains) maintained genetic differentiation despite rut overlap with Fortymile. Our data reveal that some herds with different ecological and behavioral attributes are demographically independent but nonetheless genetically connected. Thus, we suggest that managing caribou for an appropriate level of genetic connectivity, while also supporting herd persistence, will be essential to conserve caribou genetic diversity in the region. [ABSTRACT FROM AUTHOR]

Erwinia amylovora, the causative agent of fire blight of pome fruits and other rosaceous plants belongs to the group of regulated quarantine pests. The aim of this work was to characterize the populations of E. amylovora in Norway and their geographical distribution. A total of 238 E. amylovora isolates recovered from symptomatic host plants in Norway between 1986 and 2004 were genotyped by means of a short sequence repeat (SSR) marker (ATTACAGA) on plasmid pEa29. The SSR region was amplified and amplicon size determined using fluorescent labelling and rapid, automated capillary gel electrophoresis. All isolates contained the pEa29 plasmid harbouring the investigated marker. In total, ten genotypes were identified, of which two were detected only once. The number of repeats varied from 3 to 13, with 43% of the isolates containing five repeats. Of 17 isolates collected between 1986 and 1991, all but one contained five repeats, whereas more variation was observed in isolates from the period 2000 to 2004. Most of the isolates (80%) originated from Cotoneaster bullatus, hence no relationship between genotype of the isolate and host species that it was isolated from could be detected. This historic data suggests multiple introductions of E. amylovora to Norway. [ABSTRACT FROM AUTHOR]

Coastal dunes are unique habitats, threatened by human activities. In biogeographical terms, coastal dunes are habitat islands, being discrete and distinct patches of similar habitat among themselves, separated from each other by a different type of habitat. Furthermore, coastal dunes harbor endemic species, adapted to living solely in the habitats found on specific dune systems. For example, the honeypot ant Myrmecocystus baja is endemic and restricted to coastal dunes of Mexico's Baja California Pacific coast. This ecological and biogeographical scenario led to the questions whether their geographical isolation is reflected in their genetic diversity and structuring, and how their demographic history is related with the formation of the dune system habitats. To answer these questions, population genetic, isolation-with-migration, and phylogeographical analyses were carried out, based on mitochondrial and five nuclear intronic markers. Minimal gene flow was detected only between two of the dune systems sampled; otherwise, the M. baja populations were found to be isolated and genetically structured, and their divergence generally pre-dated the modern-day dune systems. It is therefore highly likely that these ants were already present in paleodunes and that each of the populations was established from founder populations as the dunes formed. These findings highlight the importance of coastal dunes for species such as the honeypot ant from Baja California, in promoting genetic differentiation. [ABSTRACT FROM AUTHOR]

The giant freshwater prawn, Macrobrachium rosenbergii, is one of the most crucial crustacean species cultured in China. However, in recent years, M. rosenbergii aquaculture in China has encountered several challenges, including low productivity and growth retardation. A decline in genetic variation has been implicated in this phenomenon. This study aims to develop microsatellite multiplex PCR panels to elucidate the genetic diversity and differentiation of cultured M. rosenbergii populations in China. Based on our previous transcriptome sequencing, we developed 24 polymorphic molecular markers. The average number of alleles (Na), observed heterozygosity (Ho), expected heterozygosity (He), and polymorphism information content (PIC) were 4.042, 0.535, 0.605, and 0.543, respectively. Two multiplex PCR panels involving six microsatellite loci were obtained by combining different amplicon lengths from these 24 loci. The panels were used to evaluate the genetic structure of six cultured M. rosenbergii populations in China, including one population in Guangxi (GX) and another in Guangdong (GD) province, along with two populations each in Jiangsu (JSA and JSB) and Zhejiang (ZJA and ZJB) provinces. Results revealed that the polymorphism among the six populations ranged from 0.365 to 0.682 with reduced genetic diversity in ZJA and JSB populations (PIC < 0.5). Pairwise FST, Nei's genetic distance, and STRUCTURE analysis revealed significant differentiation among the six cultured populations. ZJA and GD exhibited pronounced genetic distinctiveness from the other populations and were consequently assigned to distinct groups. Populations GX and JSB (FST=0.058, DA=0.045) and populations ZJB and JSA (FST=0.009, DA=0.016) were assigned to two clusters, respectively, suggesting they share similar origins. This study provided polymorphic microsatellite markers and genetic diversity assessment of cultured M. rosenbergii populations, laying a foundation for future breeding programs. [ABSTRACT FROM AUTHOR]

Knowledge of genetic variability within and among types and breeds of dromedary (Camelus dromedarius L.) can be a valuable asset in selective breeding of desirable characteristics and will shed light on their origin, dynamics of domestication, and dispersion. Variability in an 809 bp segment of the mtDNA genome was measured within and among dromedaries from eight indigenous and one exogenous breed from Ha'il in north-central Saudi Arabia. Sixteen mtDNA haplotypes were identified among 47 camels. Haplotypic diversity among breeds is high (Hd = 0.817); most of the AMOVA variance (55.05%) occurs within breeds. Phylogenetic comparison of these haplotypes with those obtained across their geographic range showed that most haplotypes were placed within the same cluster with ancient wild dromedaries and the two newly identified haplotypes in this study. The most prevalent haplotypes found in dromedaries from this area appear to be ancestral to most other dromedaries and differ from each other by only one SNP. These results support the hypothesis that the Arabian Peninsula is a hub of diversification for dromedaries. [ABSTRACT FROM AUTHOR]

Hard-to-reach communities represent Peru's main challenge for malaria elimination, but information about transmission in these areas is scarce. Here, we assessed Plasmodium vivax (Pv) and P. falciparum (Pf) transmission dynamics, resistance markers, and Pf hrp2/3 deletions in Nueva Jerusalén (NJ), a remote, indigenous community in the Peruvian Amazon with high population mobility. We collected samples from November 2019 to May 2020 by active (ACD) and passive case detection (PCD) in NJ. Parasites were identified with microscopy and PCR. Then, we analyzed a representative set of positive-PCR samples (Pv = 68, Pf = 58) using highly-multiplexed deep sequencing assays (AmpliSeq) and compared NJ parasites with ones from other remote Peruvian areas using population genetics indexes. The ACD intervention did not reduce malaria cases in the short term, and persistent malaria transmission was observed (at least one Pv infection was detected in 96% of the study days). In Nueva Jerusalen, the Pv population had modest genetic diversity (He = 0.27). Pf population had lower diversity (He = 0.08) and presented temporal clustering, one of these clusters linked to an outbreak in February 2020. Moreover, Pv and Pf parasites from NJ exhibited variable levels of differentiation (Pv Fst = 0.07–0.52 and Pf Fst = 0.11–0.58) with parasites from other remote areas. No artemisin resistance mutations but chloroquine (57%) and sulfadoxine-pyrimethamine (35–67%) were detected in NJ's Pf parasites. Moreover, pfhrp2/3 gene deletions were common (32–50% of parasites with one or both genes deleted). The persistent Pv transmission and the detection of a Pf outbreak with parasites genetically distinct from the local ones highlight the need for tailored interventions focusing on mobility patterns and imported infections in remote areas to eliminate malaria in the Peruvian Amazon. [ABSTRACT FROM AUTHOR]

India's rich diversity encompasses individuals from varied geographical, cultural, and ethnic backgrounds. In the field of population genetics, comprehending the genetic diversity across distinct populations plays a crucial role. This study presents significant findings from genetic data obtained from the Sikkimese population of India. Autosomal markers were crucial for evaluating forensic parameters, with a combined paternity index of 1 × 109. Notably, Penta E emerged as a distinguishing marker for individual identification in the Sikkim population. Fst genetic distance values revealed insights into genetic isolation among different groups, enhancing our understanding of population dynamics in the central Himalayan region. The NJ-based phylogenetic tree highlighted close genetic relationships, of the Sikkim population with the Nepalese population surrounding neighbouring Himalayan populations providing glimpses into common ancestry. In summary, this study contributes valuable data to population genetics and underscores the importance of genetic variation in comprehending population dynamics and forensic applications. [ABSTRACT FROM AUTHOR]

Seagrass beds are ecologically and economically important coastal ecosystems, and seagrass-associated organisms are a key part of their biodiversity. Marine organisms that reproduce through broadcast spawning are likely to have less genetic differentiation among populations than those that use other modes of reproduction, but this has not been well studied. Here, we investigated the genetic diversity, genetic differentiation, and migration patterns of the seagrass-associated sea star Protoreaster nodosus across 12 sites spanning approximately 2500 km from the Ryukyu Archipelago, Japan, to the Philippines. We genotyped 405 individuals by using seven microsatellite loci and analyzed allelic richness and expected heterozygosity as indices of genetic diversity. Of these two indices, only expected heterozygosity decreased slightly with increasing latitude. These results suggest that genetic diversity has not clearly decreased, even in the isolated Ryukyu Archipelago populations. Geographic distance was significantly correlated with genetic differentiation (pairwise FST: − 0.005 to 0.049). However, populations in the Ryukyu Archipelago and the Philippines showed relatively low genetic structuring and the pairwise genetic differentiation between these regions was often non-significant. Analysis of historical migration rates showed bidirectional north–south migration, which appears to be influenced by the Kuroshio Current and its countercurrents. [ABSTRACT FROM AUTHOR]

Lake Baikal, an ancient, massive lake in Siberia that holds 20% of the world’s fresh water reserves, is a unique center of speciation. Changes in the lake’s ecosystem in recent years require comprehensive monitoring activities to track the continuously evolving situation. Sponges are bioindicators of the state of aquatic ecosystems, and in Lake Baikal sponges are represented by both cosmopolitan and endemic species. However, the study of intra- and interspecific relationships between endemic sponges is complicated by the fact that standard molecular genetic markers are not suitable for these purposes. In this regard, the search for suitable high-resolution molecular genetic markers is especially relevant. Here we report on the development of a set of universal microsatellite markers that allows the interspecific relationships between Lake Baikal endemic sponges to be studied. We tested the effectiveness of this set of microsatellite markers on representatives of four endemic sponge species and achieved a reliable separation of representatives of all four genera of the endemic sponge family Lubomirskiidae. This is the first report of a set of highly variable molecular genetic markers that has been developed specifically for the study of interspecific relationships between Lake Baikal sponges. This set also has the potential to be a marker for species identification, which is important for monitoring activities in connection with events of mass death and diseases of sponges in Lake Baikal. The described approach can be used to study endemic sponges from other ancient lakes. It has great potential for use in the development of universal markers for identifying groups of closely related species. [ABSTRACT FROM AUTHOR]

Urogenital schistosomiasis remains a pervasive health challenge in rural Zambian communities. This study explores the molecular epidemiology and genetic diversity of Schistosoma haematobium using mitochondrial genes (cox1 and nadh1). Urine samples from 421 children in Siavonga and Lusaka districts, Zambia, were collected between December 2020 and February 2022. Microscopy and DNA extraction facilitated the identification of S. haematobium, followed by amplification, sequencing, and phylogenetic analysis of cox1 and nadh1 genes. Phylogenetic analysis revealed clustering with samples from mainland African countries, emphasizing shared haplotypes. Both mitochondrial genes exhibited substantial diversity, with 5 haplotypes from 37 cox1 sequences and 12 haplotypes from 23 nadh1 sequences. High haplotype diversity (0.621–0.808) and low nucleotide diversity (0.00181–0.03288) were observed. Siavonga and Lusaka districts shared the majority of S. haematobium haplotypes. Molecular variance and genetic differentiation analysis indicated variations within populations rather than between populations (cox1: -0.025, nadh1: 0.01646). These findings suggest a limited differentiation between S. haematobium populations in Siavonga and Lusaka, potentially indicating gene flow. Tajima's test revealed negative values, indicating a departure from neutrality, introduction of rare alleles, and recent population expansion. This study contributes essential insights into S. haematobium population genetics, crucial for effective urogenital schistosomiasis control in Zambia. [ABSTRACT FROM AUTHOR]

Uncovering the mechanisms driving the genetic divergence of environmentally heterogeneous species is one of the biggest challenges in phylogeography. In the present study, the genetic variation and genetic structure of the Coilia nasus were examined by analyzing thirteen mitochondrial protein-coding genes (PCGs) among 60 individuals collected from 8 populations in affiliated waters of Yangtze River and their adjacent waters. Contrasted to the recently recognized multiple subdivision, our reconstructed phylogenetic tree, analysis of molecular variance (AMOVA), FST and haplotype networks refined only two previously recognized clades, with one clade arising from the Dongting and Poyang lakes affiliated to the upper reach of Yangtze River, and the other mainly from the remaining populations. Historical demography analysis revealed that the divergence time between the two clades could be recovered to 60.05 ka, indicating a possible role of late Pleistocene glaciers in their differentiation, possibly via isolation of diverged glaciers' refugia. Subsequent positive selection test revealed no diverged selective pressures acting on the two clades within all 13 PCGs, suggests that the observed mitochondrial lineage divergence of C. nasus in the Yangtze River and its adjacent waters was primarily driven by neutral evolution. Our results provided new insights into the spatial patterns of genetic variation in population of C. nasus and would provide valuable implications for sustainable management and utilization of this fishery resource in the future. [ABSTRACT FROM AUTHOR]

Comparing the genetic diversity across different generations within tropical tree populations is an understudied topic. To assess the potential genetic consequences and conservation implications of contemporary disturbances, a population genomic study of Palaquium obovatum across age classes was undertaken. Trees and juveniles were sampled from ten different localities (eight in Singapore, two in Peninsular Malaysia) and subjected to double digest restriction-site associated DNA-sequencing (ddRAD-seq) to assess intergenerational genetic differences and investigate population structure in a hexaploid lineage. Genetic erosion, characterised by reduced heterozygosity, was found to have occurred in almost all wild populations over time, the exceptions being in one isolated coastal population and some areas with cultivated occurences. Population structure was highly localised with the number of genetically distinct populations usually following geographically separated districts, which indicates limitations in pollen and seed dispersal between fragments, possibly due to declines in the associated assemblage of dispersers. For this reason, the germplasm for conserving species diversity in degraded habitats and forest fragments should be selected from a wide range of wild populations across the landscape. [ABSTRACT FROM AUTHOR]

Recent conservation efforts to protect rare and endangered aquatic species have intensified. Nevertheless, the ornate spiny lobster (Panulirus ornatus), which is prevalent in the Indo-Pacific waters, has been largely ignored. In the absence of a detailed genomic reference, the conservation and population genetics of this crustacean are poorly understood. Here, We assembled a comprehensive chromosome-level genome for P. ornatus. This genome—among the most detailed for lobsters—spans 2.65 Gb with a contig N50 of 51.05 Mb, and 99.11% of the sequences with incorporated to 73 chromosomes. The ornate spiny lobster genome comprises 65.67% repeat sequences and 22,752 protein-coding genes with 99.20% of the genes functionally annotated. The assembly of the P. ornatus genome provides valuable insights into comparative crustacean genomics and endangered species conservation, and lays the groundwork for future research on the speciation, ecology, and evolution of the ornate spiny lobster. [ABSTRACT FROM AUTHOR]

Physella acuta is a freshwater snail native to North America. Understanding the phylogeography and genetic structure of P. acuta will help elucidate its evolution. In this study, we used mitochondrial (COI and 16S rDNA) and nuclear (ITS1) markers to identify the species and examine its genetic diversity, population structure, and demographic history of P. acuta in Thailand. Phylogenetic and network analyses of P. acuta in Thailand pertained to clade A, which exhibits a global distribution. Analysis of the genetic structure of the population revealed that the majority of pairwise comparisons showed no genetic dissimilarity. An isolation-by-distance test indicates no significant correlation between genetic and geographical distances among P. acuta populations, suggesting that gene flow is not restricted by distance. Demographic history and haplotype network analyses suggest a population expansion of P. acuta, as evidenced by the star-like structure detected in the median-joining network. Based on these results, we concluded that P. acuta in Thailand showed gene flow and recent population expansion. Our findings provide fundamental insights into the genetic variation of P. acuta in Thailand. [ABSTRACT FROM AUTHOR]

The white-bellied pangolin is subject to intense trafficking, feeding both local and international trade networks. In order to assess its population genetics and trace its domestic trade, we genotyped 562 pangolins from local to large bushmeat markets in western central Africa. We show that the two lineages described from the study region (WCA and Gab) were overlapping in ranges, with limited introgression in southern Cameroon. There was a lack of genetic differentiation across WCA and a significant signature of isolation-by-distance possibly due to unsuspected dispersal capacities involving a Wahlund effect. We detected a c. 74.1–82.5% decline in the effective population size of WCA during the Middle Holocene. Private allele frequency tracing approach indicated up to 600 km sourcing distance by large urban markets from Cameroon, including Equatorial Guinea. The 20 species-specific microsatellite loci provided individual-level genotyping resolution and should be considered as valuable resources for future forensic applications. Because admixture was detected between lineages, we recommend a multi-locus approach for tracing the pangolin trade. The Yaoundé market was the main hub of the trade in the region, and thus should receive specific monitoring to mitigate pangolins' domestic trafficking. Our study also highlighted the weak implementation of CITES regulations at European borders. [ABSTRACT FROM AUTHOR]

Chaco is the largest remaining continuous tropical dry forest on the American continent and has one of the highest deforestation rates in the world. Copernicia alba Morong ex Morong & Britton is a typical species of Chaco forests and has been subjected to predatory extraction in its areas of occurrence. This study aims to assess the diversity and genetic structure of C. alba populations in the Brazilian Chaco region. By employing single-nucleotide polymorphism (SNP) markers, this research seeks to generate insights to guide effective management and conservation strategies for this palm tree. To obtain the SNPs, genomic libraries were developed using the genotyping-by-sequencing (GBS) approach. Populations showed considerable levels of genetic diversity (HE). The inbreeding coefficient (f) was negative for all populations, indicating an excess of heterozygotes. Additionally, clear signs of genetic flow were observed, indicating low to moderate genetic differentiation between populations. We detected 65 outlier SNPs associated mainly with general metabolic processes. Despite these results, conservation efforts should be adopted to avoid the loss of genetic variation. Conservation in situ or ex situ is pointed out as an important strategy for the preservation of C. alba populations, prioritizing sampling throughout the distribution area. The information obtained in this study will contribute to the conservation of genetic diversity, increasing the chances of the natural populations of C. alba persisting over time. [ABSTRACT FROM AUTHOR]

In recent years, the insertion/deletion (InDel) polymorphism has become a preferred genetic marker in forensic genetics due to its low mutation rates and small amplicon sizes. In this study, a 36-InDelplex identification panel, consisting of autosomal 34 InDel loci, 1 Y InDel locus, and amelogenin, was developed, and gene frequencies in the Turkish population were determined. The loci of the InDel panel with global minimum allele frequencies (MAF) ≥ 0.4 were selected from the 1000 Genomes Project Phase 3 data. The amplicon sizes of the loci were designed in the range of 69-252 bp. In the validation study of the developed panel, analysis threshold, dynamic range, sensitivity, stochastic threshold, inhibitor tolerance, and reproducibility parameters were studied by following the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines. The sensitivity studies indicated that complete and reliable InDel profiles could be obtained with 0.25 ng of DNA. A population study was evaluated using 250 samples from Turkey. The mean observed heterozygosity ratio (Ho) of all loci was 0.48. The combined discrimination power (CPD) is 0.999999999990867 and the combined exclusion probability (CPE) was 0.9930. The population comparison was also made using Turkish and the five major populations from the 1000 Genomes Phase 3 populations' data (Africa, Europe, East Asia, South Asia, and America). In conclusion, the results showed that the 36-InDelplex panel is a reliable, sensitive, and accurate system that is suitable for human identification and population genetics purposes. [ABSTRACT FROM AUTHOR]

Fixation index (Fst) statistics provide critical insights into evolutionary processes affecting the structure of genetic variation within and among populations. Fst statistics have been widely applied in population and evolutionary genetics to identify genomic regions targeted by selection pressures. The FSTest 1.3 software was developed to estimate four Fst statistics of Hudson, Weir and Cockerham, Nei, and Wright using high-throughput genotyping or sequencing data. Here, we introduced FSTest 1.3 and compared its performance with two widely used software VCFtools 0.1.16 and PLINK 2.0. Chromosome 1 of 1000 Genomes Phase III variant data belonging to South Asian (n = 211) and African (n = 274) populations were included as an example case in this study. Different Fst estimates were calculated for each single-nucleotide polymorphism (SNP) in a pairwise comparison of South Asian against African populations, and the results of FSTest 1.3 were confirmed by VCFtools 0.1.16 and PLINK 2.0. Two different sliding window approaches, one based on a fixed number of SNPs and another based on a fixed number of base pair (bp) were conducted using FSTest 1.3 and VCFtools 0.1.16. Our results showed that regions with low coverage genotypic data could lead to an overestimation of Fst in sliding window analysis using a fixed number of bp. FSTest 1.3 could mitigate this challenge by estimating the average of consecutive SNPs along the chromosome. FSTest 1.3 allows direct analysis of VCF files with a small amount of code and can calculate Fst estimates on a desktop computer for more than a million SNPs in a few minutes. FSTest 1.3 is freely available at https://github.com/similab/FSTest. [ABSTRACT FROM AUTHOR]

Mus cypriacus is one of three small palaeoendemic mammals that have survived the Mediterranean islands' anthropization. This species, endemic to Cyprus, was described in 2006 and stands out as one of the last mammal species to have been discovered in Europe. Despite scarce data on its genetics, ecology, and life-history traits, Mus cypriacus is assessed as Least Concern LC in the IUCN Red List, partly due to its morphological similarity with the sympatric house mouse that prevented earlier identification. Our study uses mitochondrial and microsatellite markers to investigate this small rodent's population genetic structure and diversity. Our analysis did not identify any population genetic structure and suggested a high genetic diversity across Cyprus. When inferring habitat preference using sample locations, it appeared that M. cypriacus utilizes a diverse variety of habitats, covering more than 80% of the island. Although these results are encouraging for the conservation status of the species, they still need to be cautiously applied as potential threats may arise due to increasing habitat destruction and changes in land use. Consequently, our encouraging results should be applied judiciously. Additional ecological data are urgently needed to gain a more comprehensive understanding of this inconspicuous endemic species. [ABSTRACT FROM AUTHOR]

Anopheles species are freshwater mosquitoes found in Turkey, where they have been the most important malaria vectors locally from the past to the present. The implementation of the integrated vector control methods have been difficult for these important malaria vectors as the different species have evolved different levels of resistance to the presently used insecticides. Population genetics research sheds light on gene flow across mosquito populations and, as a result, the likelihood of the spread of insecticide resistance genes across geographical regions. Considering the importance of these vectors, we analyzed the genetic structure and gene flow levels of six An. sacharovi and An. superpictus populations by using eight microsatellite markers. Anopheles samples were collected from different areas of the Aegean region of Turkey. Genotyping was carried out by using eight microsatellite markers on the ABI Prism 310 Genetic Analyzer. Genetic analyses indicated a relatively high level of genetic variation in Anopheles populations. The results revealed low genetic differentiation and moderate amounts of gene flow for both species among distinct populations. Also, significant genetic differentiation between the plurality of the population pairs analyzed was not found to be relevant to the geographic distances between populations. This is the first study to investigate the population genetics of the main malaria vectors, An. sacharovi and An. superpictus. Breeding habits, host feeding of Anopheles species, different collection times or points, climate, and variable effective population sizes may be some factors in the genetic diversity and genetic differentiation that have been observed between the populations. [ABSTRACT FROM AUTHOR]

Corylus avellana L. stands as one of the world's most coveted nuts, thriving in the wild within the Fandoguloo forests of Iran's Ardabil province and showcasing remarkable diversity in this region. To assess the distribution of genetic diversity within and between populations, 78 genotypes from various regions of Iran, including Ardabil, Arasbaran, and Miyaneh, underwent analysis using Start Codon Targeted (SCoT) polymorphism. Additionally, the phytochemical characteristics of Corylus avellana L., such as ash, taxol, total phenol, palmitic acid, fiber, palmitoleic acid, carbohydrate, stearic acid, flavonoid, oleic acid, linoleic acid, fat, antioxidant compounds, and total phenol, were examined. The results revealed that 15 SCoT primers amplified 165 polymorphic polymerase chain reaction fragments, with the SC3 and SC21 primers exhibiting the highest and lowest polymorphic information content, respectively. The calculated marker index for the primers ranged from 2.6 to 6.1. The Ardabil population boasted the highest allele frequency, with a 100% polymorphism rate across all studied primers. The primers SC21, SC20, and SC5 showed the highest polymorphic rates among the populations with 14 fragments. The gene flow within populations was 0.4, whereas the gene flow between populations was 0.7, and the fixation index (Fst) was 0.4. This research underscores the effectiveness of the SCoT marker in gauging the genetic diversity of C. avellana, making it a promising foundation for future research on the population and evolutionary genetics of this economically significant species. [ABSTRACT FROM AUTHOR]

Habitat fragmentation is among the greatest threats to arachnids present in the forests, especially to Enoploctenus cyclothorax (Ctenidae), which is widely distributed in the Atlantic Forest of southern and southeastern Brazil. Fragmented populations, whether due to anthropic or stochastic factors, tend to be more susceptible to extinction, since genetic diversity is reduced in small and isolated populations. Considering this, the current work aimed to understand how the genetic variability is distributed in six populations of E. cyclothorax (120 individuals sampled), sampled in fragments of the Atlantic Forest in Paraná (Brazil), based on Single Nucleotide Polymorphism (SNP) genotyping. The results obtained support the separation of E. cyclothorax into two distinct genetic groups in the state, based mainly on analyses of genetic structure and connectivity. A strong and significant genetic structure was observed in the species, supported by the k = 3 estimated using Bayesian analysis, by the high values of FST genetic differentiation, and by the low gene flow identified between the genetic groups. Corroborating these results, isolation by distance and the presence of a genetic barrier in the evaluated populations were evidenced. Population genomic analysis also revealed non-homogeneous genetic diversity in E. cyclothorax (HE = 0.14 to 0.31). The hypothesis that population fragmentation could possibly impact the genetic variability of E. cyclothorax throughout the state was confirmed by the inferred data, which point to phytophysiognomy, geographical distance, and forest fragmentation as factors that shaped the current genetic structure identified in the evaluated populations. [ABSTRACT FROM AUTHOR]

Kenngoor (Phascogale calura) persist in < 1% of their original distribution, occupying highly fragmented remnant habitat in south-west Western Australia, with very little known of the genetic diversity of the remaining wild populations. Recently, the species has been translocated to managed reserves to improve its conservation. Understanding genetic structure and patterns of genetic diversity is crucial to inform conservation translocations for species recovery. This study aims to (1) assess genetic structure and genetic diversity across remaining wild locations, (2) assess long-term genetic outcomes of a mixed-source wild-to-wild translocation, and (3) estimate global effective population size. We genotyped 209 samples from 13 locations of fragmented remnant habitat using reduced representation sequencing. An isolation by distance model best explained genetic structure across the survey areas, with evidence of fine scale divergence of two northern locations. Allelic richness and autosomal heterozygosity measures indicated that diversity is spread uniformly across locations, and no locations showed signs of inbreeding or strong genetic drift. The mixed-source translocation has retained the diversity of the wider species ten years post-translocation. Overall, our results suggest that connectivity between survey areas has largely been maintained and that no location has substantially lower genetic diversity, despite the highly fragmented nature of remnant kenngoor habitat. Future translocations should aim to represent a mixture of genetically divergent locations to maintain the diversity present at the species level. Ongoing conservation management will be required to ensure the long-term viability of the species in this fragmented landscape. [ABSTRACT FROM AUTHOR]

Metapopulations are dynamic, and population genetics can reveal both spatial and temporal metapopulation variation. Yet, population genetic studies often focus on samples collected within a single time period or combine samples taken across time periods due to limited resources and the assumption that these approaches capture patterns and processes occurring over decadal and longer temporal scales. However, this may leave important fine-scale temporal variation in genetic composition undetected, particularly for metapopulations in which dynamic populations are expected. We investigated temporal patterns of population genetic diversity, effective population size, and differentiation across three sample periods for a dryland amphibian metapopulation. We sampled nine distinct Arizona treefrog (Hyla (Dryophytes) wrightorum) breeding ponds in 2014, 2018/2019, and 2021 and genotyped 17 microsatellite loci to quantify spatial and temporal population genetic dynamics. Genetic diversity within and between populations varied significantly among years. Most notably, we identified a concerning decline in allelic richness across populations, with an average − 26.11% difference between a population's first and last sample period. Effective population sizes were generally small (Ne < 100) and variable within and among populations over time, with many populations falling below common conservation thresholds by the final sample period. Trends in global genetic diversity, as measured by heterozygosity, and population differentiation were relatively consistent across all sampling periods. Overall, we found that "snapshot" or single-time sampling approaches may miss temporal variability in genetic composition that has important conservation implications, including early warning signs of decline in genetic diversity. [ABSTRACT FROM AUTHOR]

Genetic diversity and population structure can have important implications for the management of threatened species. This is particularly true for small, isolated populations that have experienced significant declines or population bottlenecks. The Norfolk Island green parrot Cyanoramphus cookii is an endangered species at risk of inbreeding and loss of genetic diversity due to its restricted range and the population bottlenecks experienced in recent decades. To assess the severity of inbreeding and loss of genetic diversity in the population we analyzed single nucleotide polymorphisms (SNPs) for 157 unique genetic samples collected from nestlings and randomly captured adult birds between 2015 and 2022. We also assessed the population for genetic structure, calculated sex ratios, and looked for evidence of past population bottlenecks. Our analysis revealed that 17.83% of individuals sampled were highly inbred (F > 0.125), although expected heterozygosity (HE) did not significantly differ from observed heterozygosity (HO) and the average inbreeding coefficient was low. The estimated effective population size (Ne) was 43.8 and we found no evidence of genetic structure. Demographic simulations provided support for scenarios including multiple population bottlenecks, when compared to those with a single population bottleneck or no past bottlenecks. We discuss the implications of our findings for the future management of the species including any potential attempt to establish an insurance population via translocation. Our study highlights the importance of considering population genetics when determining appropriate management actions for threatened species and the need to assess non-model species on an individual basis. [ABSTRACT FROM AUTHOR]

Insights from conservation genomics have dramatically improved recovery plans for numerous endangered species. However, most taxa have yet to benefit from the full application of genomic technologies. The mountain yellow-legged frog species complex, Rana muscosa and Rana sierrae, inhabits the Sierra Nevada mountains and Transverse/Peninsular Ranges of California and Nevada. Both species have declined precipitously throughout their historical distributions. Conservation management plans outline extensive ongoing recovery efforts but are still based on the genetic structure determined primarily using a single mitochondrial sequence. Our study used two different sequencing strategies – amplicon sequencing and exome capture – to refine our understanding of the population genetics of these imperiled amphibians. We used buccal swabs, museum tissue samples, and archived skin swabs to genotype frog populations across their range. Using the amplicon sequencing and exome capture datasets separately and combined, we document five major genetic clusters. Notably, we found evidence supporting previous species boundaries within Kings Canyon National Park with some exceptions at individual sites. Though we see evidence of genetic clustering, especially in the R. muscosa clade, we also found evidence of some admixture across cluster boundaries in the R. sierrae clade, suggesting a stepping-stone model of population structure. We also find that the southern R. muscosa cluster had large runs of homozygosity and the lowest overall heterozygosity of any of the clusters, consistent with previous reports of marked declines in this area. Overall, our results clarify management unit designations across the range of an endangered species and highlight the importance of sampling the entire range of a species, even when collecting genome-scale data. [ABSTRACT FROM AUTHOR]

A weedy rye, Secale cereale subsp. segetale found in Xinjiang, China, possess strong stress tolerance, tillering capacity and many useful traits. The study aims to better understand the genetic diversity of segetale rye from China at the molecular level. The genetic diversity of 92 populations (bulked samples) and further 168 plants (individual samples from 14 populations) in the segetale rye were analyzed using 47 polymorphic EST-SSR (expressed sequence tags derived microsatellite) molecular markers. A total of 211 bands were amplified by 47 EST-SSR primers in the 92 populations. Among them, there were 190 polymorphic bands, with an average of 4.04 bands per primer and an average polymorphic ratio of 88.4%. The variation range of PIC (polymorphic information content) was 0.16–0.94 with the average 0.75, indicating abundant genetic diversity of weedy rye populations. The clustering analysis of 92 populations based on Nei's genetic distance showed that their average genetic distance was near 0.35, and 92 populations from different regions of Xinjiang were relatively scattered, generally close genetic distance between populations in the same region. Similar rule was found between individual plants in same population using clustering and principal coordinate analysis (PCoA). To 168 individual plants from 14 populations, analysis found that the average genetic differentiation among populations was 0.143, and the genetic diversity of the segetale rye populations mainly existed within populations (85.7%). Abundant genetic diversity was found within different regions and populations of segetale rye from China. The research provides a theoretical basis on the application of elite genes of segetale rye to the genetic improvement of rye and wheat. [ABSTRACT FROM AUTHOR]

Acquiring DNA from wild bats (Mammalia: Chiroptera) is typically undertaken utilizing highly invasive (but non-lethal) sampling techniques comprising wing biopsies and occasional blood samples. While non-invasive sampling is possible through the extraction of DNA from faecal samples, it is not always possible to acquire samples from individual bats whilst conducting fieldwork, and as such, this method is primarily applicable to roost occupancy identification. Similarly, wing swabbing is liable to cross-contamination from roost mates. Here we present the first use of oral (buccal) swabbing for successful, species-resolution DNA sequencing of Vespertilionidae and Rhinolophidae in 10 bat species (nine Vespertilionidae and one Rhinolophidae) from the UK. [ABSTRACT FROM AUTHOR]

Thirty polymorphic microsatellites were developed and characterised for the aquaculture important species, Green chromide, Etroplus suratensis through Illumina Sequencing with a mean read quality (Phred score) of 35.8 and the microsatellite primers were designed from the sequenced information, considering various attributes such as the number of repeats, Tm, GC content, Product size, etc. using the software PRIMER 3.0 web tool. The allele numbers ranged from 6 to 18. The mean observed heterozygosity was 0.745 and the mean expected heterozygosity was 0.762. The average PIC value for 30 microsatellite primers was 0.80 and all the loci had PIC values > 0.75. The identified polymorphic loci would help in revealing the genetic stock identification among the Pearlspot population. [ABSTRACT FROM AUTHOR]

Forests help to reduce global warming by capturing and storing atmospheric carbon. Understanding the genetics of keystone species at a population level is vital for the management and sustainable utilization of forest genetic resources. A comprehensive population genetics study was carried out on Rubroshorea curtisii, an important widespread hill dipterocarp species in Peninsular Malaysia. A total of 41 populations across its distribution range in Peninsular Malaysia were collected to elucidate the genetic diversity and ultimately provide management guidelines for this species. The population samples were analysed using 10 polymorphic microsatellite loci and sequenced with three chloroplast DNA (cpDNA) regions. A total of 145 alleles were derived from the microsatellite loci, and 21 haplotypes were identified based on 1,113 bp of concatenated cpDNA sequences. The populations showed moderately high genetic diversity (mean HE = 0.627 for microsatellite gene diversity and HT = 0.574 for average haplotype diversity) but low genetic differentiation (FST = 0.036). Using Bayesian clustering, the studied populations can be divided into two groups, one of which shows further substructuring. Further sub-structuring in Cluster 1 led to sub-clustering of 1a and 1b. Bottleneck analysis did not detect any recent bottleneck events. Based on our findings, priority areas for in situ and ex situ conservation and minimum population size are recommended for the sustainable utilization of R. curtisii. [ABSTRACT FROM AUTHOR]

In the European Union, African swine fever (ASF) affects wild boar (Sus scrofa) populations in several Member States. Knowledge of population connectivity is important for the implementation of control measures, in particular the establishment of effective barriers. Population genetic comparisons of neighbouring populations can be very helpful in this respect. The present study investigated the genetic differentiation of wild boar in eastern Germany. This region has been affected by ASF since September 2020. A total of 1,262 wild boars from 31 hunting grounds (populations) in ASF-affected and ASF-free districts were sampled over a total area of almost 100,000 km². The study area encompassed a network of geographical factors that promote (roads, rivers, cities) or inhibit (natural areas, habitat corridors) genetic differentiation between wild boar populations. The genetic differentiation of the areas was based on 12 microsatellite markers. Three different Bayesian algorithms were used to analyse the data. The results were combined into a common approach with 9 clusters. Based on the cluster distribution in each population, the connectivity between the areas was quantified. The strongest differentiation was found along an imaginary line along the lower Elbe valley through Berlin and the A11 freeway to the Szczecin Lagoon. In contrast, the Mecklenburg Lake District and the south-east of the study area showed strong connectivity between areas. The special features of the landscapes along the lower Elbe valley, which was assessed as highly connective, and the high barrier effect of the A11 freeway in contrast to the other freeways in the study area show that barrier effects cannot be generalised in principle, but are actually determined by the circumstances of individual structures. The results of the connectivity analysis were compared with the distribution of viral lineages and variants. The genotypes of the wild boar populations and the ASFV lineages and variants showed a good explanatory approach for the observed disease dynamics in the study area. The newly gained knowledge on barriers and regionally different connectivity between wild boar populations can support considerations and measures for the containment of ASF in the affected areas by improving the understanding of wild boar dispersal dynamics. [ABSTRACT FROM AUTHOR]