Control Region Sequences Research Articles

Analysis of maternal genetic structure of mitochondrial DNA control region from Tai-Kadai-speaking Buyei population in southwestern China

BackgroundEven though the Buyei are a recognised ethnic group in southwestern China, there hasn’t been much work done on forensic population genetics, notably using mitochondrial DNA. The sequences and haplogroups of mitochondrial DNA control regions of the Buyei peoples were studied to provide support for the establishment of a reference database for forensic DNA analysis in East Asia.Methods and resultsThe mitochondrial DNA control region sequences of 200 Buyei individuals in Guizhou were investigated. The haplotype frequencies and haplogroup distribution of the Buyei nationality in Guizhou were calculated. At the same time, the paired Fst values of the study population and other populations around the world were computed, to explore their genetic polymorphism and population relationship. A total of 179 haplotypes were detected in the Buyei population, with frequencies of 0.005–0.015. All haplotypes were assigned to 89 different haplogroups. The haplotype diversity and random matching probability were 0.999283 and 0.0063, respectively. The paired Fst genetic distances and correlation p-values among the 54 populations revealed that the Guizhou Buyei was most closely related to the Henan Han and the Guizhou Miao, and closer to the Hazara population in Pakistan and the Chiang Mai population.ConclusionsThe study of mitochondrial DNA based on the maternal genetic structure of the Buyei nationality in Guizhou will benefit the establishment of an East Asian forensic DNA reference database and provide a reference for anthropological research in the future.

Morphological differences yet genetic similarity among seasonal cohorts of Japanese anchovy during the early life stages in the Kii Channel

Abstract Species in the genus Engraulis show extensive intraspecific as well as interspecific morphological and genetic diversity. Since morphological differences do not necessarily correspond to genetic differences, it is necessary to clarify the relationship between morphological differences and genetic differences for a better understanding of the population structure. Fish morphology at a given standard length differs between cohorts of Japanese anchovy Engraulis japonicus during the early life stages in the Kii Channel, but it is unknown whether the differences are caused by genetic differences or not. The Kii Channel includes the boundary between the Pacific (southern side of the Kii Channel) and the Seto Inland Sea stocks (northern side), but stock separation is based primarily on demographic characteristics. In the present study, genetic analyses were conducted to examine the genetic differences among samples (month and area) based on mitochondrial DNA cytochrome b region (Cyt b), control region (CR) and microsatellite markers. AMOVA revealed that the percentage of genetic variation among samples was low at 0.11% for Cyt b, 0.30% for CR and 0.00% for microsatellite, and no significant genetic variation was observed among samples. Although two clades were identified in the unrooted neighbour-joining tree for Cyt b and CR, both Cyt b and CR sequences were similar between months and between areas. Accordingly, the morphological differences among cohorts can be attributed to phenotypic plasticity. Additionally, there were no genetic differences between samples from the southern side and the northern side of the Kii Channel, suggesting strong genetic connectivity in these areas.

Genetic identification of Penaeus monodon from incipient invasions in the Yucatán Peninsula, south-southeast Gulf of Mexico

In the western Atlantic, the presence of the invasive tiger shrimp Penaeus monodon has been recorded since 1987. Established and incipient populations are reported from North Carolina, USA, to Sergipe, Brazil. In the Yucatán Peninsula, in the south-southeast Gulf of Mexico, the first sightings of P. monodon were reported in 2014. To date, the sparse records suggest an ongoing incipient invasion, providing a time-critical opportunity for early biological assessment. In the present study, two wild adults of P. monodon are reported for Rio Lagartos Lagoon, Yucatán, situated in the innermost part of the southeast Gulf of Mexico, close to the Caribbean Sea. Penaeus monodon identification was initially assessed based on macroscopic morphological features. Molecular analyses were used to corroborate morphological identification. A BLAST search was conducted by comparing partial sequences (510 bp) of the mtDNA control region (CR) of tiger shrimps from Yucatán (used as queries) with sequences deposited in the GenBank database. A Maximum Likelihood phylogenetic tree, generated from BLAST top hits (E-value cutoff = 0), revealed that sequences from Yucatán were most closely related to native sequences submitted from Indonesia. This accurate species identification has implications since this invasive shrimp threatens native biodiversity. The probable regional routes of the spread of P. monodon to the south-southeast Gulf of Mexico are discussed.

Identifying the source rookery of green turtles (Chelonia mydas) found in feeding grounds around the Korean Peninsula.

Determining the genetic diversity and source rookeries of sea turtles collected from feeding grounds can facilitate effective conservation initiatives. To ascertain the genetic composition and source rookery, we examined a partial sequence of the mitochondrial control region (CR, 796 bp) of 40 green turtles (Chelonia mydas) collected from feeding grounds around the Korean Peninsula between 2014 and 2022. We conducted genetic and mixed-stock analyses (MSA) and identified 10 CR haplotypes previously reported in Japanese populations. In the haplotype network, six, three, and one haplotype(s) grouped with the Japan, Indo-Pacific, and Central South Pacific clades, respectively. The primary rookeries of the green turtles were two distantly remote sites, Ogasawara (OGA) and Central Ryukyu Island (CRI), approximately 1,300 km apart from each other. Comparing three parameters (season, maturity, and specific feeding ground), we noted that OGA was mainly associated with summer and the Jeju Sea, whereas CRI was with fall and the East (Japan) Sea ground. The maturity did not show a distinct pattern. Our results indicate that green turtles in the feeding grounds around the Korean Peninsula originate mainly from the Japan MU and have genetic origins in the Japan, Indo-Pacific, and Central South Pacific clades. Our results provide crucial insights into rookeries and MUs, which are the focus of conservation efforts of the Republic of Korea and potential parties to collaborate for green turtle conservation.

Genetic diversity of a recovering European roller (Coracias garrulus) population from Serbia.

The European Roller (Coracias garrulus), a long-distance migratory bird, faced a considerable decline in breeding pairs throughout Europe at the end of the 20th century. Due to conservation efforts and the installation of nesting boxes, the population of the European Roller in Serbia has made a remarkable recovery. Here, we used the variability of nucleotide sequences of the mitochondrial DNA (mtDNA) control region and 10 microsatellite loci to assess the genetic diversity and structuring, phylogeographic patterns and demographic history of this species using 224 individuals from Serbia. Our results showed moderate level of genetic diversity (HO = 0.392) and a slightly elevated level of inbreeding and homozygosity (FIS = 0.393). Genetic structuring based on microsatellite data indicated three genetic clusters, but without a clear spatial pattern. High haplotype diversity (Hd = 0.987) of the mtDNA control region sequences was detected, and neutrality tests indicated a recent demographic expansion. The phylogeographic analysis, which also included previously published sequences of the mtDNA control region, supported the subdivision into two distinct European and Asian haplogroups (ΦST = 0.712). However, the results of our study showed that a larger number of haplotypes sampled in Serbia are clustered in the Asian haplogroup as compared to previous studies, indicating a historically continuous distribution of this species and possibly a wider distribution of the subspecies Coracias garrulus semenovwi. Our results suggest that the European Roller population in Serbia is genetically stable, with no evidence of recent bottlenecks, and emphasize the importance of artificial nest boxes for promoting and maintaining population dynamics of European Rollers.

Genetic Diversity of Blue Swimming Crab (Portunus pelagicus) from a Crab Bank Project and Wild Crabs in Trang and Krabi Province, Thailand Using mtDNA Control Region Sequences

Genetic Diversity of Blue Swimming Crab (Portunus pelagicus) from a Crab Bank Project and Wild Crabs in Trang and Krabi Province, Thailand Using mtDNA Control Region Sequences

Assessment of genetic diversity, population structure and wolf-dog hybridisation in the Eastern Romanian Carpathian wolf population

The Carpathian Mountains have been constantly inhabited by grey wolves and present one of the largest distribution areas in Europe, comprising between 2300 and 2700 individuals in Romania. To date, however, relatively little is known about the Romanian wolf population. We aimed to provide a first assessment of genetic diversity, population structure and wolf-dog hybridisation based on 444 mostly non-invasively collected samples in the Eastern Romanian Carpathians. Pack reconstruction and analysis of population genetic parameters were performed with mitochondrial DNA control-region sequencing and microsatellite genotyping. We found relatively high levels of genetic diversity, which is similar to values found in previous studies on Carpathian wolves from Poland and Slovakia, as well as to the long-lasting Dinaric-Balkan wolf population. We found no significant population structure in our study region, suggesting effective dispersal and admixture. Analysis of wolf-dog hybridisation using a Single Nucleotide Polymorphism panel optimised for hybrid detection revealed low rates of admixture between wolves and domestic dogs. Our results provide evidence for the existence of a genetically viable wolf population in the Romanian Carpathians. The genetic data obtained in this study may serve as valuable baseline information for the elaboration of monitoring standards and management plans for wolves in Romania.

Molecular Characterization of Mare Families in the Serbian Population of the Lipizzan Horse

Summary The Lipizzan horse breed was established in the 16th century in Lipica and later spread throughout Central and Eastern Europe. In addition to six classical stallion lines, 17 classical mare family lines were established in the old Lipica stud. Additional 44 mare family lines, including local lines, were established in other Lipizzan studs. The founders of the classical Lipizzan mare family lines date back to the period between the 18th and 20th century and came from various breeds, including the Karst, Spanish, Italian, Kladruber and Arabian horses. The history of the Lipizzan mare family lines is well described and supported by the availability of 44 nucleotide sequences of the mtDNA control region. In this study, the mtDNA control region of 23 Serbian Lipizzans, representing the established Lippizan mare family lines, as well as the local mare family line Zora, have been sequenced. The objective of this study was to test whether the Zora mare family line could be distinguished from other Lipizzan mare family lines according to the mtDNA sequence. Sequences were aligned to the entire set of mtDNA control region sequences representing 44 Lipizzan mtDNA haplotypes. Based on the alignment, a median-joining network was constructed. The individuals in this study formed a cluster with the existing Lipizzan mare family lines. However, a total of ten individuals belonging to the local Zora mare family line formed a compact cluster close to the mtDNA haplotypes, representing the classical mare family lines Wera, Betalka, and Monteaura. Additional pedigree data are needed to clarify the origin of the mtDNA haplotype variant identified in this study.

HPV18 L1 and long control region sequences variation and E6/E7 differential expression in nasopharyngeal and cervical cancers: a comparative study

BackgroundThe role of high-risk human papillomaviruses (hr-HPVs) in cervical cancer (CC) pathogenesis has long been established. Knowledge about the involvement of hr-HPVs in the etiology of nasopharyngeal cancers (NPC) was not well appreciated until the early 2000s when a clear link began to emerge. However, it is not clear whether HPV oncogenesis in the different epithelial cancers is associated with L1 gene and long-control region (LCR) sequences variation. This study aimed to investigate the HPV18 L1 gene and LCR sequences variation in cervical and nasopharyngeal biopsies, and assessed E6 and E7 genes expression level in both cancers.MethodFour-hundred and three (403) formalin-fixed paraffin-embedded tissues originating from nasopharyngeal (NPC) (279) and cervical (CC) (124) sites were collected from a pathology laboratory, Pathologist Without Borders, Accra, Ghana. Haematoxylin and eosin staining was carried out to confirm the presence of cancer on prepared biopsy sections. DNA was extracted from the confirmed cancer biopsies, followed by PCR using MY09/GP5+ /6+ primers to detect the presence of HPV and specific primers for the amplification of L1 gene and LCR. Sanger sequencing was carried out to determine HPV genotypes, and L1 and LCR sequences variant of HPV18s in CC and NPC biopsies. The HPV18 E6/E7 mRNA expression pattern in both cancers was determined using RT-qPCR.ResultsMost of the NPC (45%) and CC (55%) biopsies were HPV18 positive. Comparison of HPV18 L1 sequences obtained from cervical and nasopharyngeal cancer tissues, the L1 sequences from the NPC were highly dissimilar with a 59–100% variation among themselves, and in relation to the reference strains. However, the L1 sequences from the CC were more similar with a 91.0–100% variation among the amplified sequences. Also, the LCR sequences from CC were quite different relative to that of NPC. Results for the differential expression of E6/E7 in the two cancers showed a higher fold change in E6 expression in the CC tissues than the NPC tissues while a reverse expression pattern was found for E7 gene.ConclusionThe current study reports for the first-time variations in HPV18 L1 and LCR sequences, and differential expression of E6/E7 genes in NPC compared to CC, suggesting a possible adaptation mechanism of the virus at different cancer sites.

Whole mitochondrial genome sequencing provides new insights into the phylogeography of loggerhead turtles (Caretta caretta) in the Mediterranean Sea

Population structure and phylogeography of the loggerhead sea turtle (Caretta caretta) have so far been assessed mainly by mitochondrial DNA (mtDNA) single-gene sequencing studies. However, phylogenetic relationships amongst matrilines, genetic characterisation of rookeries and mixed-stock analyses have suffered from the limited resolution obtained by comparison of relatively short sequences such as from the mtDNA control region. Whole mitogenome sequencing can significantly improve population genetics, particularly in marine organisms showing female natal philopatry. Despite mitogenomics becoming increasingly common in biodiversity monitoring and conservation, only a few complete mitogenomes are available for C. caretta. In this study, we sequenced the complete mtDNA of 61 loggerhead turtles sampled between 2008 and 2021 along the Italian coastline and central Mediterranean Sea. We assigned complete mtDNA haplotypes to dead embryos and bycatch samples, and introduced a first nomenclature for loggerhead mitogenomes. Analysis of mtDNA diversity, Maximum Parsimony and Bayesian phylogenetic reconstruction allowed improved resolution of lineages with respect to studies reporting on partial mtDNA control region sequence comparisons, and we were able to further inform previous analyses on loggerhead ancestry based on control region haplogroups. Overall, whole mitogenome analysis has potential for considerable improvement of evolutionary history and phylogeographic investigations as well as mixed-stock surveys of loggerhead turtles.

Genetic diversity and population structure of Saurida undosquamis in the South China Sea based on Cytb and the control region

The brushtooth lizardfish, Saurida undosquamis (Richardson, 1848), is a valuable warm-water bottom fish with medicinal and economic value. This study utilized mitochondrial DNA cytochrome b (Cytb) and control region (CR) sequences to study the genetic diversity, population structure, and historical dynamics of four S. undosquamis populations in the South China Sea. Results showed that the alignment length of Cytb was 892 bp and that of the CR was 969 bp. In total, 59 polymorphic loci were detected in Cytb, defining 58 haplotypes. The overall haplotype and nucleotide diversity of the four populations were 0.9497 and 0.0041, respectively, and 104 polymorphic loci were detected in the CR, defining 97 haplotypes. The overall haplotype and nucleotide diversity of the four populations were 0.9980 and 0.0109, respectively. The haplotype phylogenetic tree, haplotype network diagram, and genetic differentiation index revealed no significant genetic differences among the four S. undosquamis populations. The results of the neutral test and mismatch analysis indicated that S. undosquamis expanded between 30.1 and 55.4 thousand years ago. The genetic diversity indicators obtained in this study will serve as basic data for future mitochondrial DNA polymorphism monitoring and research on S. undosquamis fishery resources.

Genetic divergences and hybridization within the Sebastes inermis complex.

The Sebastes inermis complex includes three sympatric species (Sebastes cheni, viz Sebastes inermis, and Sebastes ventricosus) with clear ecomorphological differences, albeit incomplete reproductive isolation. The presence of putative morphological hybrids (PMH) with plausibly higher fitness than the parent species indicates the need to confirm whether hybridization occurs within the complex. In this sense, we assessed the dynamics of genetic divergence and hybridization within the species complex using a panel of 10 microsatellite loci, and sequences of the mitochondrial control region (D-loop) and the intron-free rhodopsin (RH1) gene. The analyses revealed the presence of three distinct genetic clusters, large genetic distances using D-loop sequences, and distinctive mutations within the RH1 gene. These results are consistent with the descriptions of the three species. Two microsatellite loci had signatures of divergent selection, indicating that they are linked to genomic regions that are crucial for speciation. Furthermore, nonsynonymous mutations within the RH1 gene detected in S. cheni and "Kumano" (a PMH) suggest dissimilar adaptations related to visual perception in dim-light environments. The presence of individuals with admixed ancestry between two species confirmed hybridization. The presence of nonsynonymous mutations within the RH1 gene and the admixed ancestry of the "Kumano" morphotype highlight the potential role of hybridization in generating novelties within the species complex. We discuss possible outcomes of hybridization within the species complex, considering hybrid fitness and assortative mating. Overall, our findings indicate that the genetic divergence of each species is maintained in the presence of hybridization, as expected in a scenario of speciation-with-gene-flow.

Mitochondrial heteroplasmy as a marker for premature coronary artery disease: analysis of the poly-C tract of the control region sequence

Abstract Mitochondrial DNA (mtDNA) differs from the nuclear genome in many aspects: a maternal inheritance pattern, being more prone to acquire somatic novo mutations, accumulative with age; and the possible coexistence of different mtDNA alleles (heteroplasmy). Mitochondria are key cellular organelles responsible for energy production, involved in complex mechanisms, including atherosclerosis. In this scenario, we aimed to evaluate mtDNA variants that could be associated with premature cardiovascular disease. We evaluated 188 consecutive patients presenting with premature myocardial infarction with ST elevation (STEMI) confirmed by coronary angiogram. mtDNA polymorphisms and clinical data were evaluated and compared with 271 individuals from the same population (control group). Tobacco consumption (80.85% vs 21.21%, p<0.01) and dyslipidemia (38.83% vs 28.41%, p=0.02) were significant more frequent among STEMI patients. Besides, C16223T mtDNA mutation and poly-C heteroplasmy were significantly more frequent among premature STEMI cases than in controls. The OR associated C16223T mtDNA mutation with an increased presence of cardiovascular risk factors. Our data suggest that mtDNA C16223T mutation and poly-C heteroplasmy may be associated with unstable atherosclerosis disease. Moreover, the presence of cardiovascular risk factors (CVRFs) was associated to C16223T mtDNA mutation, with a cumulative effect. Protective mitochondrial pathways are potential therapeutic targets. Thus, preventing exposure to the damaging mechanisms associated to CVRFs is of the utmost importancemtDNA sanger analysisBaseline characteristics.

Genetic Analysis of Mingrelians Reveals Long-Term Continuity of Populations in Western Georgia (Caucasus).

To elucidate the population history of the Caucasus, we conducted a survey of genetic diversity in Samegrelo (Mingrelia), western Georgia. We collected DNA samples and genealogical information from 485 individuals residing in 30 different locations, the vast majority of whom being Mingrelian speaking. From these DNA samples, we generated mitochondrial DNA (mtDNA) control region sequences for all 485 participants (female and male), Y-short tandem repeat haplotypes for the 372 male participants, and analyzed all samples at nearly 590,000 autosomal single nucleotide polymorphisms (SNPs) plus around 33,000 on the sex chromosomes, with 27,000 SNP removed for missingness, using the GenoChip 2.0+ microarray. The resulting data were compared with those from populations from Anatolia, the Caucasus, the Near East, and Europe. Overall, Mingrelians exhibited considerable mtDNA haplogroup diversity, having high frequencies of common West Eurasian haplogroups (H, HV, I, J, K, N1, R1, R2, T, U, and W. X2) and low frequencies of East Eurasian haplogroups (A, C, D, F, and G). From a Y-chromosome standpoint, Mingrelians possessed a variety of haplogroups, including E1b1b, G2a, I2, J1, J2, L, Q, R1a, and R1b. Analysis of autosomal SNP data further revealed that Mingrelians are genetically homogeneous and cluster with other modern-day South Caucasus populations. When compared with ancient DNA samples from Bronze Age archaeological contexts in the broader region, these data indicate that the Mingrelian gene pool began taking its current form at least by this period, probably in conjunction with the formation of a distinct linguistic community.

Hares from the Late Pleistocene of Ukraine: a phylogenetic analysis and the status of Lepus tanaiticus (Mammalia, Lagomorpha)

AbstractHares (genus Lepus) are widely distributed in Europe, and they are adapted to various types of habitats. Many species are known to hybridise, and previous molecular genetic studies have revealed recurrent introgressions between species at all stages of the genus’s radiation. The Don hare (Lepus tanaiticus) was described from the Late Pleistocene of the Southern Urals and subsequently reported from coeval deposits of various regions of northern Eurasia. It is morphologically close to the mountain hare (Lepus timidus) and recent studies of mitochondrial DNA questioned its status as an independent species. Here we compare cytochrome b and control-region sequences of mtDNA of arctic Lepus, including, for the first time, eight specimens from Late Pleistocene localities of Ukraine, in order to analyse the phylogenetic relationships between representatives of different taxa. The phylogenetic tree and haplotype network analyses do not support the taxonomic distinctness of the Don hare, and only specimens of Lepus arcticus and Lepus othus form monophyletic groups based on the control-region sequences. Instead, L. tanaiticus are scattered among specimens of L. timidus. The obtained results support the hypothesis that the Don hare is an ancient morphotype of L. timidus, and its distinctive morphological traits are the result of increased geographical variation of the latter due to range expansion and adaptation to the specific conditions of the periglacial biome, similarly to other Late Pleistocene small-mammal species.

Population genetic diversity in Nezara viridula by analysis of mitochondrial control region sequences

Abstract Here, we examine genetic diversity and dispersal patterns in populations of the agricultural pest Nezara viridula from Argentina using mitochondrial control region sequences. The DNA sequence comparisons of 1837 base pairs of the control region revealed 60 haplotypes determined by a total of 108 variable sites. The observed total haplotype diversity (Hd) value was 0.99, and the nucleotide diversity was 0.00423 and 0.00571 according to π and θW, respectively. The high haplotype diversity and low nucleotide diversity, as well as both neutrality tests and unimodal mismatch distributions, suggested a recent expansion in the populations of N. viridula from Argentina. The expansion of the populations of this insect is probably due to the recent agricultural expansion and intensification of soybean cultivation in this country. No significant levels of genetic differentiation were detected, suggesting that gene flow predominates over genetic drift. In addition, the Bayesian individual assignment analysis revealed that all populations share ancestry. It is probable that the growth in the area cultivated with soybean has generated stable and continuous habitats that allow gene flow among populations of N. viridula. The results of demographic history analysis suggest that the direction of migration of N. viridula would be associated with the growth pattern of soybean crops in Argentina.

Diversity of mitochondrial DNA in 3 species of great whales before and after modern whaling.

The 20th century commercial whaling industry severely reduced populations of great whales throughout the Southern Hemisphere. The effect of this exploitation on genetic diversity and population structure remains largely undescribed. Here, we compare pre- and post-whaling diversity of mitochondrial DNA (mtDNA) control region sequences for 3 great whales in the South Atlantic, such as the blue, humpback, and fin whale. Pre-whaling diversity is described from mtDNA extracted from bones collected near abandoned whaling stations, primarily from the South Atlantic island of South Georgia. These bones are known to represent the first stage of 20th century whaling and thus pre-whaling diversity of these populations. Post-whaling diversity is described from previously published studies reporting large-scale sampling of living whales in the Southern Hemisphere. Despite relatively high levels of surviving genetic diversity in the post-whaling populations, we found evidence of a probable loss of mtDNA lineages in all 3 species. This is evidenced by the detection of a large number of haplotypes found in the pre-whaling samples that are not present in the post-whaling samples. A rarefaction analysis further supports a loss of haplotypes in the South Atlantic humpback and Antarctic blue whale populations. The bones from former whaling stations in the South Atlantic represent a remarkable molecular archive for further investigation of the decline and ongoing recovery in the great whales of the Southern Hemisphere.

Philopatry influences the genetic population structure of the blacktip shark (Carcharhinus limbatus) at multiple spatial scales.

Understanding how interactions among microevolutionary forces generate genetic population structure of exploited species is vital to the implementation of management policies that facilitate persistence. Philopatry displayed by many coastal shark species can impact gene flow and facilitate selection, and has direct implications for the spatial scales of management. Here, genetic structure of the blacktip shark (Carcharhinus limbatus) was examined using a mixed-marker approach employing mitochondrial control region sequences and 4339 SNP-containing loci generated using ddRAD-Seq. Genetic variation was assessed among young-of-the-year sampled in 11 sites in waters of the United States in the western North Atlantic Ocean, including the Gulf of Mexico. Spatial and environmental analyses detected 68 nuclear loci putatively under selection, enabling separate assessments of neutral and adaptive genetic structure. Both mitochondrial and neutral SNP data indicated three genetically distinct units-the Atlantic, eastern Gulf, and western Gulf-that align with regional stocks and suggest regional philopatry by males and females. Heterogeneity at loci putatively under selection, associated with temperature and salinity, was observed among sites within Gulf units, suggesting local adaptation. Furthermore, five pairs of siblings were identified in the same site across timescales corresponding with female reproductive cycles. This indicates that females re-used a site for parturition, which has the potential to facilitate the sorting of adaptive variation among neighbouring sites. The results demonstrate differential impacts of microevolutionary forces at varying spatial scales and highlight the importance of conserving essential habitats to maintain sources of adaptive variation that may buffer species against environmental change.

Maternal diversity of the Yellow-faced sheep of Kecskemét based on the mtDNA control region

Regarding the Yellow-faced sheep of Kecskemét or Sand-sheep, known as a variant of Yellow-faced Berke sheep, very little research has been undertaken to date and the small population, which is mainly found in the southern region of Hungary, is at risk of extinction. In this study blood samples from Yellow-faced sheep of Kecskemét were selected for Control Region (CR) sequencing and subsequent analysis. These were compared with CR data available from GenBank resources and other indigenous Hungarian breeds in order to compare and contrast the differences and similarities between these. A total of 40 individuals from 2 flocks in the South of Hungary were sampled in 2020. Investigations were performed based on the total number of sites (1174 bps) of the CR. It was revealed that the relative genetic diversity within the Yellow-faced sheep of Kecskemét (haplotype and nucleotide diversity 0.950 and 0.01635, respectively), in comparison to other indigenous breeds, albeit from a limited population, cannot be deemed a narrow genetic pool. The values of the Tajima D test, Fu’s Fs statistic, Fu & Li’s D*- and F* tests were found to be non-significant (in each case P > 0.10). Statistical evaluation does not indicate a lack of alleles. This study demonstrated three haplogroups within the Yellow-faced sheep of Kecskemét population – A, B and C. Haplogroup B was the most prevalent, which is typical for European sheep breeds, given an understanding about their arrival into Europe from the Near East. This is comparative to other Hungarian breeds, such as the Cikta and Polled Racka, and also similar to the native breeds of neighbouring countries. Regarding Haplogroup A, which was found to a minor frequency, being lower than that found in the Cikta or Polled Racka, but to a greater extent than Tsigai. To date, haplogroup C, which is typically demonstrated in sheep from Central Asia, had only been discovered in one native Hungarian breed: the Cikta, however its presence was also discovered in the Sand-sheep. The examination of the haplogroups seems to confirm the fact that the sheep came to Hungary not only from Asia Minor, but also from the interior of Asia in the past, and the mitochondrial genetic information of these latter animals maintained in some representatives of today's breeds, surviving the effects of crossbreeding and selection.

Genetic data reveal wintering ground affiliation of humpback whales from the Mexican Central Pacific

ABSTRACTTwo groups of humpback whales inhabit the waters off the Pacific coast of Mexico the coastal wintering aggregation in the north (MX), and the southern Mexico/Central America wintering aggregation (S‐MX/CEA) in the south. However, along the coast of the Mexican Central Pacific (MCP), the population affiliation of humpback whales is uncertain. Some studies have concluded that the MCP whales are part of S‐MX/CEA, while others have suggested that the MCP may represent an overlap zone between the two wintering aggregations. In this study, data from 354 biopsy samples were collected over a 12‐year period, to provide insight from genetic information into the affiliation of MCP whales to and the boundaries between the wintering aggregations. Using mitochondrial control region sequences, we found that the majority (73%) of MCP whales are part of MX, but that the boundary between the two wintering aggregations may shift latitudinally depending on environmental conditions. The high haplotypic (h ± SD = 0.859 ± 0.0138) and nucleotide diversity (π ± SD = 0.0145 ± 0.0075) of the MCP whales are also consistent with our sample, including animals from both wintering aggregations. More research is needed to better describe the ranges of the MX and S‐MX/CEA wintering aggregations to ensure their successful conservation and management.