mtDNA Haplotypes Research Articles

Mitochondrial genetic variation and risk of chronic kidney disease and acute kidney injury in UK Biobank participants

Experimental models suggest an important role for mitochondrial dysfunction in the pathogenesis of chronic kidney disease (CKD) and acute kidney injury (AKI), but little is known regarding the impact of common mitochondrial genetic variation on kidney health. We sought to evaluate associations of inherited mitochondrial DNA (mtDNA) variation with risk of CKD and AKI in a large population-based cohort. We categorized UK Biobank participants who self-identified as white into eight distinct mtDNA haplotypes, which were previously identified based on their associations with phenotypes associated with mitochondrial DNA copy number, a measure of mitochondrial function. We used linear and logistic regression models to evaluate associations of these mtDNA haplotypes with estimated glomerular filtration rate by serum creatinine and cystatin C (eGFRCr-CysC, N = 362,802), prevalent (N = 416 cases) and incident (N = 405 cases) end-stage kidney disease (ESKD), AKI defined by diagnostic codes (N = 14,170 cases), and urine albumin/creatinine ratio (ACR, N = 114,662). The mean age was 57 ± 8 years and the mean eGFR was 90 ± 14 ml/min/1.73 m2. MtDNA haplotype was significantly associated with eGFR (p = 2.8E−12), but not with prevalent ESKD (p = 5.9E−2), incident ESKD (p = 0.93), AKI (p = 0.26), or urine ACR (p = 0.54). The association of mtDNA haplotype with eGFR remained significant after adjustment for diabetes mellitus and hypertension (p = 1.2E−10). When compared to the reference haplotype, mtDNA haplotypes I (β = 0.402, standard error (SE) = 0.111; p = 2.7E−4), IV (β = 0.430, SE = 0.073; p = 4.2E−9), and V (β = 0.233, SE = 0.050; p = 2.7E−6) were each associated with higher eGFR. Among self-identified white UK Biobank participants, mtDNA haplotype was associated with eGFR, but not with ESKD, AKI or albuminuria.

Linear DNA-driven recombination in mammalian mitochondria.

Mitochondrial DNA (mtDNA) recombination in animals has remained enigmatic due to its uniparental inheritance and subsequent homoplasmic state, which excludes the biological need for genetic recombination, as well as limits tools to study it. However, molecular recombination is an important genome maintenance mechanism for all organisms, most notably being required for double-strand break repair. To demonstrate the existence of mtDNA recombination, we took advantage of a cell model with two different types of mitochondrial genomes and impaired its ability to degrade broken mtDNA. The resulting excess of linear DNA fragments caused increased formation of cruciform mtDNA, appearance of heterodimeric mtDNA complexes and recombinant mtDNA genomes, detectable by Southern blot and by long range PacBio® HiFi sequencing approach. Besides utilizing different electrophoretic methods, we also directly observed molecular complexes between different mtDNA haplotypes and recombination intermediates using transmission electron microscopy. We propose that the known copy-choice recombination by mitochondrial replisome could be sufficient for the needs of the small genome, thus removing the requirement for a specialized mitochondrial recombinase. The error-proneness of this system is likely to contribute to the formation of pathological mtDNA rearrangements.

Population genetic structure of the provincially endangered mainland Eastern Moose (<i>Alces americanus americanus</i>) in Nova Scotia, Canada

Eastern Moose (Alces americanus americanus (Clinton, 1822)) on mainland Nova Scotia (MNS) are declining and experience limited immigration across the Isthmus of Chignecto from the larger population in neighbouring New Brunswick. Provincially Endangered, the recovery strategy for MNS Moose involves mitigating various threats that may lead to local extirpation. We examine genetic diversity of MNS Moose using microsatellite markers and mitochondrial (mtDNA) control region sequences. Genetic similarities with the Alces a. americana population in New Brunswick and the introduced Northwestern Moose (Alces americanus andersoni (= Alces alces andersoni) Peterson, 1952) population on Cape Breton Island are also analysed. Observed heterozygosity for microsatellites for MNS Moose was low and there was also evidence of limited gene flow between Nova Scotia and New Brunswick across the narrow Isthmus of Chignecto that connects these provinces. Consistent with relatively recent colonization of North America by Moose dispersing across the Bering Land Bridge <15 000 years ago, mtDNA haplotypes of MNS Moose were identical or extremely similar to haplotypes found across North America. However, mtDNA diversity was lower in Nova Scotia and New Brunswick than in more central regions of the species’ range. Active measures to maintain habitat that promote connectivity across the Isthmus of Chignecto would likely be valuable for Moose in terms of maintaining genetic variation in the region and reducing inbreeding.

Human fascioliasis emergence in southern Asia: Complete nuclear rDNA spacer and mtDNA gene sequences prove Indian patient infection related to fluke hybridization in northeastern India and Bangladesh

Fascioliasis is a snail-borne zoonotic disease with impact on the development of human subjects and communities. It is caused by two liver-infecting fasciolid trematode species, the globally-distributed Fasciola hepatica and the Africa/Asia-restricted but more pathogenic, larger F. gigantica. Fasciola gigantica is the cause of endemicity in livestock throughout the warm lowlands from Pakistan to southeastern Asia since old times. Human fascioliasis is emerging in this region at present, with an increase of patient reports. Complete sequences of rDNA ITS-1 and ITS-2 spacers and mtDNA nad1 and cox1 genes were obtained from fasciolid eggs found in the endoscopic bile aspirate from a patient of Arunachal Pradesh, northeastern India. Egg measurements, pronounced ITS heterozygosity, and pure F. gigantica mtDNA haplotypes demonstrate an infection by a recent F. gigantica-like hybrid. Sequence identities and similarities with the same DNA markers found in livestock from Bangladesh prove the human-infecting fasciolid to present identical ITSs and nad1 haplotypes and only one silent transversion in cox1 when compared to a widely-spread combined haplotype in animals. In northeastern India and Bangladesh, human fascioliasis emergence appears linked to increasing livestock prevalences due to: ruminant importation from other countries because of the increasing demand of rapidly growing human populations; numerous livestock movements, including transborder corridors, due to the uncontrolled small-scale household farming practices; and man-made introduction of F. hepatica with imported livestock into an area originally endemic for F. gigantica leading to frequent hybridization. Sequences, phylogenetic trees, and networks indicate that the origins of intermediate/hybrid fasciolids and factors underlying human infection risk differ in eastern and western South Asia. The emergence scenario in southern China and Vietnam resembles the aforementioned of northeastern India and Bangladesh, whereas in Pakistan it is linked to increasing monsoon rainfall within climate change combined with an impact of an extensive irrigation system. Past human-guided movements of pack animals along the western Grand Trunk Road and the eastern Tea-Horse Road explain the F. gigantica mtDNA results obtained. Physicians should be aware about these emerging scenarios, clinical pictures, diagnostic techniques and treatment. Government authorities must appropriately warn health professionals, ensure drug availability and improve livestock control.

Conservation implications of high gene flow and lack of pronounced spatial genetic structure in elephants supported by contiguous suitable habitat in north‐western India

AbstractThe western Terai Arc Landscape (wTAL) in Uttarakhand, India, marks the range limit for the Asian elephant in north‐western India. This region has been impacted by land‐use changes and infrastructure expansion for the last seven decades. To evaluate the impact of habitat deterioration on the population structure of elephants in the region, we characterized their genetic diversity and local genetic structure using mitochondrial (D loop) and nuclear DNA (microsatellites; n = 15) markers. We used tissue samples of 114 elephants from five different sub‐populations, collected between 2005 and 2014. The genetic variation was moderate (HO = 0.49–0.55) compared with other Indian elephant populations. Two mtDNA haplotypes were identified without strong spatial patterns across wTAL. Bayesian individual‐based clustering algorithm identified two genetic clusters (K = 2) with high admixture (50% at Q < 0.7) and no spatial adherence. Though K = 1 was not supported by the Bayesian algorithm, multivariate analysis and sibship patterns did not indicate genetic differentiation. The lack of spatial genetic structuring suggests high levels of gene flow, indicating that this population is still panmictic. This suggests that the life history traits of elephants as well as the ecological features of this landscape influence genetic connectivity. However, ongoing land use changes necessitate regular genetic monitoring in wTAL to identify incipient structuring caused by anthropogenic barriers to movement.

Mitochondrial DNA diversity and maternal origins of Pakistani donkey.

Domestic donkey plays a key role as a draft animal in rural economy of Pakistan where its population is increasing every year. The complete mtDNA control region of forty randomly sampled donkeys was PCR- amplified and sequenced bi-directionally using specific primers. Distinct mtDNA haplotypes obtained in the current study (KY446001-KY446011) were subjected to haplotype (h) and nucleotide diversity (π) measures using DnaS as well as to phylogenetic, Network, and AMOVA analyses. There were a total 27 polymorphic sites present within 11 unique mtDNA haplotypes from the studied 40 animals from different regions. Neighbor-joining network and median-joining network both illustrated the splitting of all these haplotypes into two well-defined Nubian and Somali lineages, confirming African maternal origin of Pakistani domestic donkey. Diversity parameters h (0.967± 0.037) and π (0.02917± 0.00307) were found to reveal high levels of genetic diversity in Pakistani donkeys. AMOVA demonstrated only 1% of genetic differences between two mtDNA maternal lineages, pointing to lack of population substructure in Pakistani donkeys as is the case with worldwide domestic donkey population. Pakistani donkeys have African maternal origin and high levels of mtDNA diversity. High genetic diversity may be due to non-selective breeding and heteroplasmy. We herein provide the first report on mtDNA diversity of control region in Pakistani domestic donkey.

Different MtDNA Haplotype Richness between Sibling Species of Myodes (Rodentia) on Hokkaido Mainland and Its Adjacent Islands, Japan

Different MtDNA Haplotype Richness between Sibling Species of Myodes (Rodentia) on Hokkaido Mainland and Its Adjacent Islands, Japan

The effect of mitochondrial recombination on fertilization success in blue mussels

The presence of doubly uniparental inheritance (DUI) in bivalves represents a unique mode of mitochondrial transmission, whereby paternal (male-transmitted M-type) and maternal (female-transmitted F-type) haplotypes are transmitted to offspring separately. Male embryos retain both haplotypes, but the M-type is selectively removed from females. Due to the presence of heteroplasmy in males, mtDNA can recombine resulting in a ‘masculinized’ haplotype referred to as Mf-type. While mtDNA recombination is usually rare, it has been recorded in multiple mussel species across the Northern Hemisphere. Given that mitochondria are the powerhouse of the cell, different mtDNA haplotypes may have different selective advantages under diverse environmental conditions. This may be particularly important for sperm fitness and fertilization success. In this study we aimed to i) determine the presence, prevalence of the Mf-type in Australian blue mussels (Mytilus sp.) and ii) investigate the effect of Mf-mtDNA on sperm performance (a fitness correlate). We found a high prevalence of recombined mtDNA (≈35 %) located within the control region of the mitochondrial genome, which occurred only in specimens that contained Southern Hemisphere mtDNA. The presence of two female mitotypes were identified in the studied mussels, one likely originating from the Northern Hemisphere, and the other either representing the endemic M. planulatus species or introduced genotypes from the Southern Hemisphere. Despite having recombination events present in a third of the studied population, analysis of sperm performance indicated no difference in fertilization success related to mitotype.

Genetic variation of European mouflon depends on admixture of introduced individuals

In the early twentieth century, European mouflon was introduced in Croatia, while all introductions in Slovenia occurred in the 1950s and 1960s. Although majority of the introductions were historically documented, occasional cases involving individuals of unknown origin have likely contributed to a mixed genetic pool in established colonies. To understand the impact of past management and the potential founder effects on contemporary mouflon populations, we performed the first genetic study of the species in these two countries. Utilising next-generation sequencing of both mitochondrial control region (mtDNA CR) and major histocompatibility complex (MHC DRB exon 2), our study scrutinises the genetic diversity and structure of these populations. Additionally, the origins and genetic variability of mouflon in Croatia and Slovenia were compared with reference samples from Czech Republic, Sardinia (Italy), and Corsica (France). The mtDNA haplotype network showed that the majority of mouflon from Slovenia are closely related to mouflon from Sardinia, and only few shared the same haplotypes with mouflon from Croatia. Some mouflon from mainland Croatia share identical or closely related haplotypes with individuals from the initially established population in this country (on the Brijuni Archipelago), while others belong to a distinctly different cluster. We found five MHC alleles previously reported for mouflon in Europe, and genetic diversity was similar in both studied countries. We observed an excess of the Ovar-DRB1*07012/*07012 genotype, and only a few individuals exhibited the advantageous genotypes for parasite infection (Ovar-DRB1*0114 allele and Ovar-DRB1*0324/*0114 genotype). Genetic data showed that the population origins are generally in agreement with the written historical records, although we found signals of release of extra individuals into certain colonies.

Mitochondrial DNA Haplogroups and Variants Predispose to Chagas Disease Cardiomyopathy

Cardiomyopathies are major causes of heart failure. Chagas disease (CD) is caused by the parasite Trypanosoma cruzi, and it is endemic in Central and South America. Thirty percent of cases evolve into chronic chagas cardiomyopathy (CCC), which has worse prognosis as compared with other cardiomyopathies. In vivo bioenergetic analysis and ex vivo proteomic analysis of myocardial tissues highlighted worse mitochondrial dysfunction in CCC, and previous studies identified nuclear-encoded mitochondrial gene variants segregating with CCC. Here, we assessed the role of the mitochondrial genome through mtDNA copy number variations and mtDNA haplotyping and sequencing from heart or blood tissues of severe, moderate CCC and asymptomatic/indeterminate Chagas disease as well as healthy controls as an attempt to help decipher mitochondrial-intrinsic genetic involvement in Chagas disease development. We have found that the mtDNA copy number was significantly lower in CCC than in heart tissue from healthy individuals, while blood mtDNA content was similar among asymptomatic Chagas disease, moderate, and severe CCC patients. An MtDNA haplogrouping study has indicated that African haplogroups were over represented in the Chagas subject groups in comparison with healthy Brazilian individuals. The European lineage is associated with protection against cardiomyopathy and the macro haplogroup H is associated with increased risk towards CCC. Using mitochondria DNA sequencing, 84 mtDNA-encoded protein sequence pathogenic variants were associated with CCC. Among them, two variants were associated to left ventricular non-compaction and two to hypertrophic cardiomyopathy. The finding that mitochondrial protein-coding SNPs and mitochondrial haplogroups associate with risk of evolving to CCC is consistent with a key role of mitochondrial DNA in the development of chronic chagas disease cardiomyopathy.

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.

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.

Population genetics of the endangered Clanwilliam sandfish Labeo seeberi: considerations for conservation management

The Cape Fold Ecoregion (CFE) is one of southern Africa’s unique aquatic ecoregions and its freshwater fish fauna is characterized by high levels of endemism. As with many other Mediterranean-type ecosystems, the region is also a hotspot for threatened and range-restricted freshwater fish. Many of the CFE’s endemic species are at risk for extinction, with declines in population sizes and distribution ranges. The Clanwilliam sandfish Labeo seeberi is an example of such a species and is considered one of South Africa’s most endangered large migratory cyprinids. This species is endemic to the Olifants/Doring river system in the CFE and has been subject to a major population decline, mainly as a result of invasive alien fish and adverse climate events. Little is known of the genetics of the Clanwilliam sandfish, thus this study aimed to provide basic population genetic parameters to inform future conservation interventions. Both microsatellite and mitochondrial DNA (mtDNA) markers were used to assess populations from three sites within the Olifants/Doring river system. Genetic diversity was moderate to low and did not reflect the drastic decline expected on the basis of previous relative abundance data. This is likely due to a lag effect between ecological/life history demographics (due to juvenile recruitment failures) and population genetic composition. Furthermore, there was limited genetic differentiation between the sampling locations, suggesting a single breeding population, but mtDNA haplotype distribution and slight divergence of the smaller populations does suggest that the population might have become recently fragmented. The results show that the effective population size of the current breeding population might still be sufficient to maintain evolutionary potential in the short term, which could act as a buffer until conservation strategies focusing on protecting breeding animals and maximizing juvenile survival can restore population numbers.

Possible Reasons Affecting Different Phytophthora infestans Populations in Tomato and Potato Isolates in Thailand

Late blight, caused by the oomycete Phytophthora infestans, is one of the most important diseases affecting tomato and potato production worldwide. In Thailand, the disease is widespread in the north and northeast, especially in the Chiang-Mai and Tak provinces. The mating type, metalaxyl sensitivity, mitochondrial DNA (mtDNA) haplotype, RG57 fingerprinting, and microsatellite were used to characterize the P. infestans populations. The study revealed that the P. infestans of tomato isolates in Thailand are of the same lineage as those from 1994 until 2002. The clonal lineages that were found in the potato populations have changed since 1994. The changes in P. infestans isolates in the potato populations have likely been the result of the import of seed potatoes to Thailand. Furthermore, the P. infestans populations in potatoes show resistance to metalaxyl, whereas those from tomato isolates show sensitivity to fungicides. The reasons for the different responses can be attributed to (i) the use of metalaxyl, (ii) the host preferences of P. infestans, and (iii) the migration of new genotypes from infected potato seeds.

Genetic features of bivalve transmissible neoplasia in blue mussels from the Kola Bay (Barents Sea) suggest a recent trans-Arctic migration of the cancer lineages.

Ecology and biogeography of bivalve transmissible neoplasia (BTN) are underexplored due to its recent discovery and a challenging diagnostics. Blue mussels harbour two evolutionary lineages of BTN, MtrBTN1 and MtrBTN2, both derived from Mytilus trossulus. MtrBTN1 has been found only in M. trossulus from North Pacific. MtrBTN2 parasitizes different Mytilus spp. worldwide. BTN in M. trossulus in the Atlantic sector has never been studied. We looked for BTN in mussels from the Barents Sea using flow cytometry of cells, qPCR with primers specific to cancer-associated alleles and sequencing of mtDNA and nuclear loci. Both MtrBTN1 and MtrBTN2 were present in our material, though their prevalence was low (~0.4%). All cancers parasitized M. trossulus except one, MtrBTN1, which was found in a hybrid between M. trossulus and M. edulis. The mtDNA haplotypes found in both lineages were nearly identical to those known from the Northwest Pacific but not from elsewhere. Our results suggest that these two lineages may have arrived in the Barents Sea in recent decades with the maritime transport along the Northern Sea Route. A young evolutionary age of MtrBTN1 seems to indicate that it is an emerging disease in the process of niche expansion. Comparing the new and the published sequence data on tumour suppressor p53, we proved that the prevalence of BTN in mussels can reach epizootic levels. The finding of diverse recombinants between paternally and maternally inherited mtDNAs in somatic tissues of M. trossulus was an unexpected result of our study.

Genetic Diversity in Pioneer Ants: The Cardiocondyla shuckardi Group

The myrmicine ant genus Cardiocondyla consists of around 80 species of small, inconspicuous ants, which live mainly in subtropical and tropical Africa, Eurasia, and Australia. Several species have been accidentally introduced to America and have also invaded numerous originally ant-free islands around the world. The diversity of life histories in this genus, with lethally fighting wingless males, dominance hierarchies among queens, and considerable variation in the sociogenetic organization of colonies across species, has made it an interesting model to investigate the evolution and behavioral ecology of reproductive strategies. Taxa of the African Cardiocondyla shuckardi group are of particular interest, as in a phylogeny they lie between facultatively polygynous species with fatal male competition and monogynous species with mutually tolerant males. Studies on male behavior and sociogenetics in C. “venustula,” a widespread member of the C. shuckardi group, showed that males defend small territories inside their subterraneous nests. At the same time, they revealed a surprisingly large variability in mtDNA haplotypes both within and between populations in South Africa, Angola, and Côte d’Ivoire. As the different lineages are very similar in morphology and nuclear markers, more research is needed to clarify the very confused taxonomic situation in this fascinating group of ants.

Origin of endemic species in a moderately isolated ancient lake: The case of a snakehead in Inle Lake, Myanmar

AbstractInle Lake is an ancient lake in Myanmar, which is an important area with unique and diverse fauna. Its ichthyofauna is believed to have formed non‐radiatively, but the historical processes are poorly understood. To elucidate the mechanisms that shape species diversity in this moderately isolated biogeographical ‘island’, this study focused on a typical endemic fish of Inle Lake, Channa harcourtbutleri (Channidae, Anabantiformes), with its widely distributed sister species, C. limbata, and estimated the historical distribution and diversification processes of the endemic fish based on genome‐wide polymorphism (MIG‐seq) and mitochondrial DNA data. Channa harcourtbutleri contained two genetically and morphologically distinct groups inhabiting Inle Lake and the surrounding rivers respectively. These two groups were genetically the closest to each other; however, the riverine group showed some similarity to the closely related species, C. limbata from Southeast Asia. The mtDNA haplotypes of the endemic species were not monophyletic; most of the riverine group had haplotypes identical or close to those of C. limbata from the upper Irrawaddy and Salween rivers. The time tree suggested that C. harcourtbutleri diverged from C. limbata in the early Pleistocene and then experienced secondary contact with C. limbata in the late Pleistocene. Genetic and morphological differentiation within C. harcourtbutleri suggests that local adaptation to different environments has played an important role for the coexistence of its two forms with some reproductive isolation. Further, the results highlight the importance of multiple colonization and allopatric speciation in shaping biodiversity in the long‐term, moderately isolated environments.

Genetic and Morphological Characterization of the Invasive Corbicula Lineages in European Russia

Despite the full attention of malacologists to the study of Corbicula clams, stimulated mainly due to their high invasive potential and unique breeding system, studies based on an integrative taxonomic approach to identify various invasive lineages of this genus in European Russia are still limited. Our fieldwork was conducted in the Don, Volga, and Caspian Sea basins. In total, four distinct morphotypes belonging to the European forms R, Rlc, S, and “Int” of Corbicula clams were distinguished. According to our molecular genetic data, two Corbicula lineages, relevant to the nominal species Corbicula fluminea and C. fluminalis, can be defined. We observed a discrepancy between mtDNA haplotypes and morphological features for all individuals that were sampled from the Don and Kura Rivers. Identified mismatch may be due to the androgenetic reproduction of Corbicula that leads to cytonuclear inconsistencies. The 28S rRNA polymorphism in C. fluminea and C. fluminalis from studied localities was recorded. This occurrence is perhaps due to hybridization events between forms R, S, and Rlc. The biogeographic origins of Corbicula invasive lineages are discussed. Corbicula fluminalis (FW17, form S) has been detected for first time in the native range, namely in Azerbaijan, Tajikistan, Turkey, and Myanmar. We assume that the invasion of C. fluminalis into reservoirs and watercourses of the Caspian Sea basin (Republic of Dagestan and Stavropol Krai of Russia) was from Western Asia and Transcaucasia, and the introduction of C. fluminea to the Don and Volga River basins was from unspecified European countries.

Range shift and introgression of three Japanese Abies species: insights from population genetic data and species distribution modeling

Range shifts during the Pleistocene shaped the unique phylogeographical structures of many species. Pleistocene range shifts gave currently allopatric species opportunities to occur in sympatry, likely resulting in ancient introgressions between related taxa. In our study, we investigate the range shifts and introgression patterns of three Japanese Abies species (A. firma, A. homolepis, and A. veitchii) by employing an extensive survey of 43 populations. This survey includes comprehensive analysis of both mitochondrial (mtDNA) and nuclear (18 microsatellites) genomes, in combination with species distribution modeling (SDM). It is important to note that these two types of markers provide distinct and complementary information, as they have different modes of inheritance and mutation rates. Bayesian clustering analysis indicates that the three species were clearly separated, with the exception of the A. homolepis var. umbellata population, which is considered a natural hybrid between A. homolepis and A. firma. However, mtDNA haplotypes of the four northern populations of A. firma were entirely replaced by two major haplotypes of A. homolepis and A. veitchii. The results of neighbor-net, NewHybrids, STRUCTURE analyses, and SDM suggest that historical introgression between species occurred in each geographic region, with mtDNA capture being the likely mechanism. However, contrary to these findings, the ABC coalescent analysis did not support an ancient introgression. Therefore, further validation with genome-wide level data is needed to clarify this issue. Our conclusion is that climate-induced range shifts during the Pleistocene/Holocene likely played a crucial role in the observed patterns of introgression in these species.

Investigating the role of mitochondrial DNA D-loop variants, haplotypes, and copy number in polycystic ovary syndrome: implications for clinical phenotypes in the Chinese population.

The presence of genetic variations in mitochondrial DNA (mtDNA) has been associated with a diverse array of diseases. The objective of this study was to examine the correlations between mtDNA D-loop, its haplotypes, and polycystic ovary syndrome (PCOS) in the Chinese population, and the associations between mtDNA D-loop and symptoms of PCOS. The study also sought to determine whether the mtDNA copy number in Chinese patients with PCOS differed from that of individuals in the control group. Infertile individuals who only had tubal or male factor treatment were the focus of research by The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). mtDNA haplotypes were categorized using polymorphic D-loop sites. mtDNA D-loop, PCOS features, and mtDNA haplotypes were analyzed using R software to determine the strength of the association between the three. There are certain DNA haplotypes linked to PCOS. Microdroplet digital polymerase chain reaction (PCR) was used to determine the mtDNA copy number in a convenience sample of 168 PCOS patients and 83 controls. Among the research group, the majority of D-loop mutations were infrequent (frequency< 1%), with only 45 variants displaying a minimum allele frequency (MAF) of 5% or higher. No association was found between polymorphism loci in PCOS patients and body mass index (BMI). Noteworthy, C194T, 1A200G, 523delAC, and C16234T showed positive correlations with elevated LH/FSH levels. Additionally, specific polymorphic loci G207A, 16036GGins, and 16049Gins within the D-loop region of mtDNA potentially exerted a protective role in PCOS development. Conversely, no statistical significance was observed in the expression levels of C16291T and T489C. Chinese women with mtDNA haplotype A15 exhibited a decreased risk of developing PCOS. Moreover, a significant difference in mtDNA copy number was detected, with controls averaging 25.87 (21.84, 34.81), while PCOS patients had a mean of 129.91 (99.38, 168.63). Certain mtDNA D-loop mutations and haplotypes appear to confer protection against PCOS in Chinese women. In addition, elevated mtDNA copy number may serve as an indicator during early stages of PCOS.