Related Haplotypes Research Articles

Epidemiology, genetic characterization and population structure analysis of lumpy skin disease virus from North India.

Lumpy skin disease (LSD) is a transboundary, viral disease of cattle with a significant economic impact on the livestock industry. This study describes the epidemiological investigations of outbreaks of LSD that occurred in 2022 in three Indian states viz., Haryana, Himachal Pradesh and Rajasthan and the genetic characterization of Lumpy skin disease viruses (LSDVs). Also, the population structure analysis of LSDVs was carried out. Out of 138 scab samples tested from suspected cattle for LSDV, 106 were found positive. Of these, nine representative scab samples were further genetically characterized. Phylogenetic analysis based on the P32 and EEV gene sequences depicted that the LSDV strains of the present study had nucleotide identity of 100% and 99.10-99.45%, respectively with the LSDV/2019 field strains of India. Multiple sequence alignment of the EEV glycoprotein gene sequences revealed nucleotide polymorphisms at three positions viz., G178A, G253A and A459G in circulating LSDV/2022 field strains. Based on the median joining network analysis of the EEV gene, 12 haplotypes were identified among the LSDV populations. Population structure analysis corresponding to the EEV gene revealed high haplotype (0.8486 ± 0.026) and low nucleotide diversities (0.00636 ± 0.0006) and negative values for neutrality indices, indicating a high number of closely related haplotypes and the studied population may have undergone a recent expansion. The findings will help in understanding the distribution and dynamics of LSDV populations, which will prove pivotal in designing and implementing effective management and control strategies.

Genetic diversity of Dotilla myctiroides (Crustacea: Brachyura: Dotillidae) based on mitochondrial cox1 gene marker in Peninsular Malaysia

ABSTRACT The present study examined the genetic diversity of two populations of Dotilla myctiroides (Milne-Edwards) from Peninsular Malaysia. Based on 640-bp COX1 (cytochrome c oxidase subunit 1) gene sequences, the D. myctiroides specimens from Peninsular Malaysia, Singapore and India formed a lineage which was distinctly separated from Dotilla wichmanni and D. fenestrata. Sixteen COX1 haplotypes were found in Peninsular Malaysia samples, with 11 haplotypes in the Morib sample, eight in the Tanjung Tuan sample, and three common haplotypes in these samples. The Singapore specimen had the commonest haplotype of Peninsular Malaysia, while the Indian specimen had a distinct haplotype. The proportions of the two most common COX1 haplotypes were not significantly different between the Morib and Tanjung Tuan samples. The difference in the mean haplotype diversity between these samples was statistically significant. However, the nucleotide diversity of the two samples was not significantly different and there was no genetic subdivision/differentiation between the two populations. The high number of closely related haplotypes indicates the possibility of a recent population expansion. The data provide valuable information for future studies on the genetic diversity, population structure and phylogeography of Dotilla species.

Universal Targeted Haplotyping by Droplet Digital PCR Sequencing and Its Applications in Noninvasive Prenatal Testing and Pharmacogenetics Analysis.

The analysis of haplotypes of variants is important for pharmacogenomics analysis and noninvasive prenatal testing for monogenic diseases. However, there is a lack of robust methods for targeted haplotyping. We developed digital PCR haplotype sequencing (dHapSeq) for targeted haplotyping of variants, which is a method that compartmentalizes long DNA molecules into droplets. Within one droplet, 2 target regions are PCR amplified from one template molecule, and their amplicons are fused together. The fused products are then sequenced to determine the phase relationship of the single nucleotide polymorphism (SNP) alleles. The entire haplotype of 10s of SNPs can be deduced after the phase relationship of individual SNPs are determined in a pairwise manner. We applied dHapSeq to noninvasive prenatal testing in 4 families at risk for thalassemia and utilized it to detect NUDT15 diplotypes for predicting drug tolerance in pediatric acute lymphoblastic leukemia (72 cases and 506 controls). For SNPs within 40 kb, phase relation can be determined with 100% accuracy. In 7 trio families, the haplotyping results for 97 SNPs spanning 185 kb determined by dHapSeq were concordant with the results deduced from the genotypes of both parents and the fetus. In 4 thalassemia families, a 19.3-kb Southeast Asian deletion was successfully phased with 97 downstream SNPs, enabling noninvasive determination of fetal inheritance using relative haplotype dosage analysis. In the NUDT15 analysis, the variant status and phase of the variants were successfully determined in all cases and controls. The dHapSeq represents a robust and scalable haplotyping approach with numerous clinical and research applications.

A large-scale screening identified in USH2A gene the P3272L founder pathogenic variant explaining familial Usher syndrome in Sardinia, Italy

BackgroundUsher syndrome (USH) encompasses a group of disorders characterized by congenital sensorineural hearing loss (SNHL) and retinitis pigmentosa (RP). We described the clinical findings, natural history, and molecular analyses of USH patients identified during a large-scale screening to identify quantitative traits related to ocular disorders in the SardiNIA project cohort.MethodsWe identified 3 USH-affected families out of a cohort of 6,148 healthy subjects. 9 subjects presented a pathological phenotype, with SNHL and RP. All patients and their family members underwent a complete ophthalmic examination including best-corrected visual acuity, slit-lamp biomicroscopy, fundoscopy, fundus autofluorescence, spectral-domain optical coherence tomography, and electrophysiological testing. Audiological evaluation was performed with a clinical audiometer. Genotyping was performed using several arrays integrated with whole genome sequence data providing approximately 22 million markers equally distributed for each subject analyzed. Molecular diagnostics focused on analysis of the following candidate genes: MYO7A, USH1C, CDH23, PCDH15, USH1G, CIB2, USH2A, GPR98, DFNB31, CLRN1, and PDZD7.ResultsA single missense causal variant in USH2A gene was identified in homozygous status in all patients and in heterozygous status in unaffected parents. The presence of multiple homozygous patients with the same phenotypic severity of the syndromic form suggests that the Sardinian USH phenotype is the result of a founder effect on a specific pathogenic variant related haplotype. The frequency of heterozygotes in general Sardinian population is 1.89. Additionally, to provide new insights into the structure of usherin and the pathological mechanisms caused by small pathogenic in-frame variants, like p.Pro3272Leu, molecular dynamics simulations of native and mutant protein–protein and protein–ligand complexes were performed that predicted a destabilization of the protein with a decrease in the free energy change.ConclusionsOur results suggest that our approach is effective for the genetic diagnosis of USH. Based on the heterozygous frequency, targeted screening of this variant in the general population and in families at risk or with familial USH can be suggested. This can lead to more accurate molecular diagnosis, better genetic counseling, and improved molecular epidemiology data that are critical for future intervention plans.Trial registrationWe did not perform any health-related interventions for the participants.

Genetic diversity of the largest African mole-rat genus, Bathyergus. One, two or four species?

Recent advances in sequencing technology and phylogenetic methods allow us to solve puzzling taxonomic questions using detailed analyses of genetic diversity of populations and gene flow between them. The genus of solitary-living dune mole-rat, Bathyergus, is quite unique among six genera of African mole-rats. The animals are by far the largest and the only scratch digging mole-rat genus possessing a skull less adapted to digging, grooved upper incisors, and more surface locomotor activity. Most authors recognize two species of dune mole-rats, B. suillus and B. janetta, but according to others, the genus is monotypic. In addition, recent molecular studies have revealed cryptic genetic diversity and suggested the existence of up to four species. In our study, we used mitochondrial and genome-wide nuclear data collected throughout the distribution of the genus to investigate the number of species. In agreement with previous studies, we found Bathyergus to be differentiated into several distinct lineages, but we also found evidence for a degree of gene flow between some of them. Furthermore, we confirmed that B. janetta is nested within B. suillus, making the latter paraphyletic and we documented an instance of local mitochondrial introgression between these two nominal species. Phylogeographic structure of the genus was found to be very shallow. Although traditionally dated to the Miocene, we found the first split within the genus to be much younger estimated to 0.82 Ma before present. Genealogical distinctiveness of some lineages was very low, and the coancestry matrix showed extensive sharing of closely related haplotypes throughout the genus. Accordingly, Infomap clustering on the matrix showed all populations to form a single cluster. Overall, our study tends to support the existence of only one species of Bathyergus namely, B. suillus. Environmental niche modelling confirmed its dependence on sandy soils and the preference for soils with relatively high carbon content. Bayesian skyline plots indicate recent population decline in the janetta lineage, probably related to global environmental change.

Impact of CYP2D6*2, CYP2D6*35, rs5758550, and related haplotypes on risperidone clearance in vivo

PurposeThe CYP2D6 gene exhibits significant polymorphism, contributing to variability in responses to drugs metabolized by CYP2D6. While CYP2D6*2 and CYP2D6*35 are presently designated as alleles encoding normal metabolism, this classification is based on moderate level evidence. Additionally, the role of the formerly called “enhancer” single nucleotide polymorphism (SNP) rs5758550 is unclear. In this study, the impacts of CYP2D6*2, CYP2D6*35 and rs5758550 on CYP2D6 activity were investigated using risperidone clearance as CYP2D6 activity marker.MethodsA joint parent-metabolite population pharmacokinetic model was used to describe 1,565 serum concentration measurements of risperidone and 9-hydroxyrisperidone in 512 subjects. Risperidone population clearance was modeled as the sum of a CYP2D6-independent clearance term and the partial clearances contributed from each individually expressed CYP2D6 allele or haplotype. In addition to the well-characterized CYP2D6 alleles (*3-*6, *9, *10 and *41), *2, *35 and two haplotypes assigned as CYP2D6*2-rs5758550G and CYP2D6*2-rs5758550A were evaluated.ResultsEach evaluated CYP2D6 allele was associated with significantly lower risperidone clearance than the reference normal function allele CYP2D6*1 (p < 0.001). Further, rs5758550 differentiated the effect of CYP2D6*2 (p = 0.005). The haplotype-specific clearances for CYP2D6*2-rs5758550A, CYP2D6*2-rs5758550G and CYP2D6*35 were estimated to 30%, 66% and 57%, respectively, relative to the clearance for CYP2D6*1. Notably, rs5758550 is in high linkage disequilibrium (R2 > 0.85) with at least 24 other SNPs and cannot be assigned as a functional SNP.ConclusionCYP2D6*2 and CYP2D6*35 encode reduced risperidone clearance, and the extent of reduction for CYP2D6*2 is differentiated by rs5758550. Genotyping of these haplotypes might improve the precision of genotype-guided prediction of CYP2D6-mediated clearance.

Effect of an endothelial regulatory module on plasma proteomics in exercising horses

Elite performing exercise requires an intricate modulation of the blood pressure to support the working muscles with oxygen. We have previously identified a genomic regulatory module that associates with differences in blood pressures of importance for elite performance in racehorses. This study aimed to determine the effect of the regulatory module on the protein repertoire. We sampled plasma from 12 Coldblooded trotters divided into two endothelial regulatory module haplotype groups, a sub-elite performing haplotype (SPH) and an elite performing haplotype (EPH), each at rest and exercise. The haplotype groups and their interaction were interrogated in two analyses, i) individual paired ratio analysis for identifying differentially abundant proteins of exercise (DAPE) and interaction (DAPI) between haplotype and exercise, and ii) unpaired ratio analysis for identifying differentially abundant protein of haplotype (DAPH). The proteomics analyses revealed a widespread change in plasma protein content during exercise, with a decreased tendency in protein abundance that is mainly related to lung function, tissue fluids, metabolism, calcium ion pathway and cellular energy metabolism. Furthermore, we provide the first investigation of the proteome variation due to the interaction between exercise and related blood pressure haplotypes, which this difference was related to a faster switch to the lipoprotein and lipid metabolism during exercise for EPH. The molecular signatures identified in the present study contribute to an improved understanding of exercise-related blood pressure regulation.

Paramutation at the maize pl1 locus is associated with RdDM activity at distal tandem repeats.

Exceptions to Mendelian inheritance often highlight novel chromosomal behaviors. The maize Pl1-Rhoades allele conferring plant pigmentation can display inheritance patterns deviating from Mendelian expectations in a behavior known as paramutation. However, the chromosome features mediating such exceptions remain unknown. Here we show that small RNA production reflecting RNA polymerase IV function within a distal downstream set of five tandem repeats is coincident with meiotically-heritable repression of the Pl1-Rhoades transcription unit. A related pl1 haplotype with three, but not one with two, repeat units also displays the trans-homolog silencing typifying paramutations. 4C interactions, CHD3a-dependent small RNA profiles, nuclease sensitivity, and polyadenylated RNA levels highlight a repeat subregion having regulatory potential. Our comparative and mutant analyses show that transcriptional repression of Pl1-Rhoades correlates with 24-nucleotide RNA production and cytosine methylation at this subregion indicating the action of a specific DNA-dependent RNA polymerase complex. These findings support a working model in which pl1 paramutation depends on trans-chromosomal RNA-directed DNA methylation operating at a discrete cis-linked and copy-number-dependent transcriptional regulatory element.

Targeted Linked-Read Sequencing for Direct Haplotype Phasing of Parental GJB2/SLC26A4 Alleles: A Universal and Dependable Noninvasive Prenatal Diagnosis Method Applied to Autosomal Recessive Nonsyndromic Hearing Loss in At-Risk Families

Noninvasive prenatal diagnosis (NIPD) for autosomal recessive nonsyndromic hearing loss (ARNSHL) has been rarely reported until recent years. Additionally, the existing method can not be used for challenging genome loci (eg, copy number variations, deletions, inversions, or gene recombinants) or on families without proband genotype. This study assessed the performance of relative haplotype dosage analysis (RHDO)-based NIPD for identifying fetal genotyping in pregnancies at risk of ARNSHL. Fifty couples carrying pathogenic variants associated with ARNSHL in either GJB2 or SLC26A4 were recruited. The RHDO-based targeted linked-read sequencing combined with whole gene coverage probes was used to genotype the fetal cell-free DNA of 49 families who met the quality control standard. Fetal amniocyte samples were genotyped using invasive prenatal diagnosis (IPD) to assess the performance of NIPD. The NIPD results showed 100% (49/49) concordance with those obtained through IPD. Two families with copy number variation and recombination were also successfully identified. Sufficient specific informative single-nucleotide polymorphisms for haplotyping, as well as the fetal cell-free DNA concentration and sequencing depth, are prerequisites for RHDO-based NIPD. This method has the merits of covering the entire genes of GJB2 and SLC26A4, qualifying for copy number variation and recombination analysis with remarkable sensitivity and specificity. Therefore, it has clinical potential as an alternative to traditional IPD for ARNSHL.

Noninvasive twin genotyping for recessive monogenic disorders by relative haplotype dosage.

To establish a haplotype-based noninvasive prenatal testing (NIPT) workflow for single-gene recessive disorders that adapt to dizygotic (DZ) twin pregnancies. Twin pregnancies at risk of Duchenne muscular dystrophy, Becker muscular dystrophy, hemophilia B, spinal muscular atrophy, phenylketonuria, and nonsyndromic hearing loss were recruited. For subsequent analysis, capture sequencing targeting highly heterozygotic single nucleotide polymorphism sites was conducted. Paternal-specific alleles were used to calculate the total and individual fetal fractions and determine zygosity. A two-step Bayes Factor model was applied to clarify the complex genomic landscape in the maternal plasma: the first step involved determining whether the twins inherited the same haplotype, and the second step involved estimating their individual genotypes. NIPT results were subsequently confirmed by invasive diagnosis. Nine twin pregnancies were recruited, including five DZ and four monozygotic (MZ) twins. The earliest gestational age was 8+0 weeks, and the minimum fetal fraction was 4.6%. Three twin pregnancies were reported with one affected fetus, while the remaining six were reported without affected fetuses. Two dichorionic diamniotic twin pregnancies were confirmed to be MZ twins. The NIPT results were 100% consistent with those of invasive procedures or diagnostic genetic testing after birth. This study is the first to perform NIPT for single-gene disorders in twin pregnancies and preliminarily confirm its clinical feasibility. Acknowledging the twins' genotypes in the first trimester is valuable as it empowers obstetric care providers and parents to have adequate time for pregnancy management and decision-making.

Unravelling the maternal evolutionary history of the African leopard (Panthera pardus pardus).

The African leopard (Panthera pardus pardus) has lost a significant proportion of its historical range, notably in north-western Africa and South Africa. Recent studies have explored the genetic diversity and population structure of African leopards across the continent. A notable genetic observation is the presence of two divergent mitochondrial lineages, PAR-I and PAR-II. Both lineages appeared to be distributed widely, with PAR-II frequently found in southern Africa. Until now, no study has attempted to date the emergence of either lineage, assess haplotype distribution, or explore their evolutionary histories in any detail. To investigate these underappreciated questions, we compiled the largest and most geographically representative leopard data set of the mitochondrial NADH-5 gene to date. We combined samples (n = 33) collected in an altitudinal transect across the Mpumalanga province of South Africa, where two populations of leopard are known to be in genetic contact, with previously published sequences of African leopard (n = 211). We estimate that the maternal PAR-I and PAR-II lineages diverged approximately 0.7051 (0.4477-0.9632) million years ago (Ma). Through spatial and demographic analyses, we show that while PAR-I underwent a mid-Pleistocene population expansion resulting in several closely related haplotypes with little geographic structure across much of its range, PAR-II remained at constant size and may even have declined slightly in the last 0.1 Ma. The higher genetic drift experienced within PAR-II drove a greater degree of structure with little haplotype sharing and unique haplotypes in central Africa, the Cape, KwaZulu-Natal and the South African Highveld. The phylogeographic structure of PAR-II, with its increasing frequency southward and its exclusive occurrence in south-eastern South Africa, suggests that this lineage may have been isolated in South Africa during the mid-Pleistocene. This hypothesis is supported by historical changes in paleoclimate that promoted intense aridification around the Limpopo Basin between 1.0-0.6 Ma, potentially reducing gene flow and promoting genetic drift. Interestingly, we ascertained that the two nuclear DNA populations identified by a previous study as East and West Mpumalanga correspond to PAR-I and PAR-II, respectively, and that they have come into secondary contact in the Lowveld region of South Africa. Our results suggest a subdivision of African leopard mtDNA into two clades, with one occurring almost exclusively in South Africa, and we identify the potential environmental drivers of this observed structure. We caution that our results are based on a single mtDNA locus, but it nevertheless provides a hypothesis that can be further tested with a dense sample of nuclear DNA data, preferably whole genomes. If our interpretation holds true, it would provide the first genetic explanation for the smaller observed size of leopards at the southernmost end of their range in Africa.

Small proteins, great promises: Geographic bioprospecting of Bowman–Birk protease inhibitors and domestication side‐effects in African cowpea (Vigna unguiculata L.)

Societal Impact StatementThe legume crop cowpea is grown worldwide, but 90% of the world's total share is produced in Africa. It is a promising species due to its resilience properties, balance of macro and micronutrients and presence of health‐promoting bioactive compounds. In African countries, cowpea has a crucial role in guaranteeing food security as a subsistence crop for families and commercial income for small farmers. The discovery of compounds with high nutraceutical value and bioactive properties supports socio‐economic policies to improve health and nutrition, especially in low‐ and middle‐income countries. In turn, this encourages biodiversity protection and crop enhancement programmes.Summary Bowman–Birk protease inhibitors (BBIs) are a restricted group of small proteins in plants mainly involved in defence mechanisms against pests. BBIs are demonstrated to be active components capable of reducing the viabilities of different cancer cell lines. BBI bioactivity is directly linked to the inhibition capacity, but the variability and the efficiency against the physiological targets of different BBI isoforms remain still unexplored. We analysed the natural genetic diversity of two main genes encoding BBI trypsin‐trypsin (BBI‐TT) and trypsin‐chymotrypsin (BBI‐TC) in wild and domesticated cowpea samples mainly spread in Sub‐Saharan Africa. We analysed DNA sequences and respective amino acidic isoforms/isoproteins to explore signs of natural selection and haplotype relationships. Moreover, we calculated the binding energy between BBIs and their biological targets to identify which are the most efficient inhibitors and their geographical locations. We found a high level of haplotype diversity for both genes, almost exclusively in wild accessions and detected positive and negative selection signals in the amino acid sequences. Furthermore, in the wild diversity pool, some BBI‐TT and BBI‐TC mature proteins were potentially better interactors with the physiological targets. The long interaction between plant‐pathogen has selected new and useful isoforms in wild lineages that have allowed the chances of survival of the species to improve. On the other hand, the domestication process has produced an intense bottleneck leaving only poorly efficient BBI variants. In addition to providing information on the natural diversity and evolution of BBIs, our work discusses the potential applications in agriculture and human health.

Expanding Access to Noninvasive Prenatal Diagnosis for Monogenic Conditions to Consanguineous Families.

Cell-free fetal DNA exists within the maternal bloodstream during pregnancy and provides a means for noninvasive prenatal diagnosis (NIPD). Our accredited clinical service offers definitive NIPD for several autosomal recessive (AR) and X-linked conditions using relative haplotype dosage analysis (RHDO). RHDO involves next-generation sequencing (NGS) of thousands of common single nucleotide polymorphism (SNPs) surrounding the gene of interest in the parents and an affected or unaffected offspring to conduct haplotype phasing of the high- and low-risk alleles. NGS is carried out in parallel on the maternal cell-free DNA, and fetal inheritance is predicted using sensitive dosage calculations performed at sites where the parental genotypes differ. RHDO is not currently offered to consanguineous couples owing to the shared haplotype between parents. Here we test the expansion of RHDO for AR monogenic conditions to include consanguineous couples. The existing sequential probability ratio test analysis pipeline was modified to apply to SNPs where both parents are heterozygous for the same genotype. Quality control thresholds were developed using 33 nonconsanguineous cases. The performance of the adapted RHDO pipeline was tested on 8 consanguineous cases. The correct fetal genotype was predicted by our revised RHDO approach in all conclusive cases with known genotypes (n = 5). Haplotype block classification accuracies of 94.5% and 93.9% were obtained for the nonconsanguineous and consanguineous case cohorts, respectively. Our modified RHDO pipeline correctly predicts the genotype in fetuses from consanguineous families, allowing the potential to expand access to NIPD services for these families.

Interspecific Sharing of Closely Related Chloroplast Genome Haplotypes among Sclerophyllous Oaks in the Hot-Dry Valley of the Jinsha River, Southwestern China

Evergreen sclerophyllous oak forests (ESOFs) in southwestern China are a special vegetation type developed in response to the expansion of arid habitats after the uplift of the Himalayas. Here, we used chloroplast (cp) DNA and nuclear ribosomal (nr) DNA to investigate the fine-scale genetic variation patterns of six sympatric oaks (Quercus, Fagaceae) in the hot-dry valley ESOFs of the Jinsha River, southwestern China. Three cp genomes were assembled for each species. Nine cp genome haplotypes and 16 nrDNA haplotypes were identified based on single-nucleotide variants and indels. Our results demonstrated that discordance existed between the cpDNA and nrDNA phylogenies of the sclerophyllous oaks in section Ilex. The nrDNA phylogeny was consistent with species boundaries, while the cpDNA phylogeny was decoupled from taxonomy. Interspecific sharing of closely related cp genome haplotypes was detected between Quercus cocciferoides and the other two sclerophyllous oaks, Q. longispica and Q. franchetii. Specifically, Q. cocciferoides and Q. longispica sampled in a mixed stand exhibited two haplotypes that differed by a 9 bp indel. The local distribution of the two highly similar haplotypes suggested that they may have arisen from ancient introgression. Given that the two species have diverged for a long time, it is possible that the ancestral cp genome of one species was captured by another species through asymmetric introgression in early times, and an indel event occurred subsequently. Phylogenetic analyses using more previously published cp genome sequences indicated that Q. cocciferoides and Q. franchetii shared multiple cpDNA lineages of Ilex oaks, which may be caused by shared ancestral polymorphism and/or ancient introgression. Our study showed that at least three highly variable regions (ψycf1, ndhF-rpl32, and trnKUUU-rps16 or rpl32-trnLUAG) can distinguish the nine haplotypes identified by whole-cp genome sequences. These markers are useful for the evolutionary studies of the maternal lineages of oaks in hot-dry valley ESOFs.

Noninvasive Prenatal Diagnosis of SEA-Thalassemia by Combining 1000 Genomes Database and Relative Haplotype Dosage

To explore a noninvasive method for diagnosis of SEA-thalassemia and to investigate whether the regional factors affect the accuracy of this method. The method involved using a public database and bioinformatics software to construct parental haplotypes for proband and predicting fetal genotypes using relative haplotype dosage. We screened and downloaded sequencing data of couples who were both SEA-thalassemia carriers from the China National Genebank public data platform, and matched the sequencing data format with that of the reference panel using Ubuntu system tools. We then used Beagle software to construct parental haplotypes, predicted fetal haplotypes by relative haplotype dosage. Finally, we used Hidden Markov Model and Viterbi algorithm to determine fetal pathogenic haplotypes. All noninvasive fetal genotype diagnosis results were compared with gold standard gap-PCR electrophoresis results. Our method was successful in diagnosing 13 families with SEA-thalassemia carriers. The best diagnostic results were obtained when Southern Chinese Han was used as the reference panel, and 10 families showed full agreement between our noninvasive diagnostic results and the gap-PCR electrophoresis results. The accuracy of our method was higher when using a Chinese Han as the reference panel for haplotype construction in the Southern Chinese Han region as opposed to Beijing Chinese region. The combined use of public databases and relative haplotype dosage for diagnosing SEA-thalassemia is a feasible approach. Our method produces the best noninvasive diagnostic results when the test samples and population reference panel are closely matched in both ethnicity and geography. When constructing parental haplotypes with our method, it is important to consider the effect of region in addition to population background alone.

First-trimester noninvasive prenatal diagnosis of seven facioscapulohumeral muscular dystrophy type 1 families using SNP-based amplicon sequencing: An earlier, rapid and safer way.

The study is to explore the feasibility and value of SNP-based noninvasive prenatal diagnosis (NIPD) for facioscapulohumeral muscular dystrophy type 1 (FSHD1) in early pregnancy weeks. We prospectively collected seven FSHD1 families, with an average gestational age of 8+6. Among these seven couples, there were three affected FSHD1 mothers and four affected fathers. A multiplex-PCR panel comprising 402 amplicons was designed to selective enrich for highly heterozygous SNPs upstream of the DUX4 gene. Risk haplotype was constructed based on familial linkage analysis. Fetal genotypes were accurately inferred through relative haplotype dosage analysis using Bayes Factor. All tests were successfully completed in a single attempt, and no recombination events were detected. NIPD results were provided within a week, which is 4 weeks earlier than karyomapping and 7 weeks earlier than Bionano single-molecule optical mapping (BOM). Ultimately, five FSHD1 fetuses and two normal fetuses were successfully identified, with a 100% concordance rate with karyomapping and BOM. Therefore, SNP-based NIPD for FSHD1 was demonstrated to be feasible and accurate in early weeks of gestation, although the risk of recombination events cannot be completely eliminated. In the future, testing of more cases is still necessary to fully determine the clinical utility.

Lack of mitochondrial introgression and limited genetic connectivity among Manyara tilapia (Oreochromis amphimelas) populations in Tanzanian Saline Rift Valley Lakes

AbstractThe Manyara tilapia (Oreochromis amphimelas), native to the Saline Rift Valley Lakes (SRVLs) in north‐central Tanzania, has recently experienced population declines mainly due to overfishing and severe droughts. This, combined with the introduction of Nile tilapia (O. niloticus), which poses a risk of hybridisation, could potentially erode essential genetic traits necessary for their survival. To address these concerns, our study analysed partial cytochrome oxidase subunit I sequences (627 base pairs) from 139 Manyara tilapia and 79 Nile tilapia specimens collected from the SRVLs to test two hypotheses: (i) whether there is no transfer of mitochondrial DNA between these species, and (ii) whether Manyara tilapia populations in the SRVLs have remained genetically connected despite reported declines. The results revealed six distinct haplotypes for Manyara tilapia and three for Nile tilapia. These haplotypes formed separate clusters for each species, with no shared or closely related haplotypes, indicating limited or no transfer of mitochondrial DNA between them. Additionally, we found evidence of restricted genetic connectivity among Manyara tilapia populations in the SRVLs, with populations in Lakes Manyara and Eyasi displaying limited genetic exchange among themselves and with those in other SRVLs. Our findings highlight the importance of sustained conservation efforts in protected areas around Lake Manyara and Lake Eyasi to safeguard the unique populations of Manyara tilapia in these lakes. However, limited connectivity with other SRVLs suggests that conservation initiatives in these areas may have a limited impact on these lakes. Thus, future efforts should prioritise stocks in Lakes Kindai, Singida and Sulunga, focusing on protecting fish refugia, particularly the rivers connected to these lakes, which serve as critical habitats during the dry season and as important reservoirs for replenishing these populations.

Ants of Kamchatka: checklist, DNA-barcoding and key (Hymenoptera, Formicidae)

Kamchatka is a remote volcanic peninsula in the sub-arctic Far East of Russia. Its myrmecofauna has been scientifically addressed several times. However, previous species lists are contradictory in part and a modern study seems to be lacking. Based on literature review, I conclude that 12 species and 4 genera (Camponotus, Formica, Leptothorax and Myrmica) of ants may be native to Kamchatka. Of those, 9 were found in the field, 3 having a Holarctic, 3 a trans-Palearctic and 3 an East Palearctic distribution. Most species diversity was found at mid-elevations, in pine shrubs and mixed forests, while deciduous forests and open habitats at lower altitudes were surprisingly species poor. DNA-barcoding was performed for 57 specimens/9 species. Genetic diversity (COI) was low for 8/9 species, with the exception of Leptothorax acervorum, for which all samples were of a different haplotype and 2 haplogroups were identified. For the encountered Holarctic and trans-Palearctic species, closely related haplotypes (&amp;lt;0.7% raw distance) occur in Europe and/or North America. Some Formica ants were morphologically atypical, with workers partially resembling those of F. fusca, while gynes identified as F. lemani. Morphometric analysis and DNA-barcoding suggested that all these specimens belong to a single species, F. lemani. Standard images for all specimens and an illustrated key to the worker caste are provided.

The RAAS system SNPs polymorphism is associated with essential hypertension risk in rural areas in northern China.

Objectives: Epidemiological evidence has shown that genetics and environment are associated with the risk of hypertension. However, the specific SNP effects of a cluster of crucial genes in the RAAS system on the risk of hypertension are unclear. Methods: A case-control study was performed on the baseline participants of Environment and Chronic Disease in Rural Areas of Heilongjiang China (ECDRAHC) study. According to the inclusion and exclusion criteria, 757 subjects (428 hypertensive patients) were enrolled. A total of 32 SNP sites and related haplotypes, involved in AGT (angiotensinogen), ACE (angiotensin-converting enzyme), AGTR1, CYP11B2 (aldosterone-synthase), LDLR (low-density lipoprotein receptor), LRP5 (low-density lipoprotein receptor associated protein 5), LRP6 (low-density lipoprotein receptor associated protein 6), PPARG (peroxisome proliferator-activated receptor gamma) and ACE2 (angiotensin-converting enzyme 2) genes which exert important roles in renin-angiotensin-aldosterone system (RAAS) system were analyzed. Furthermore, a polygenic scoring model was established to assess individual risk of developing hypertension based on the comprehensive SNPs effects in genes related the RAAS system. Results: After controlling the impact of confounding factors, multivariate logistic regression analysis revealed that the distribution of AGT/rs5046, LRP6/rs12823243 and ACE2/rs2285666 was associated with susceptibility to essential hypertension. In genetic score model, the score > -0.225 had a higher risk, the OR (95%CI) was 1.229 (1.110, 1.362). Conclusions: To the best of our knowledge, this is the first time a hypertension risk scoring model on RAAS associated gene cluster has been constructed, which will provide a novel approach for prevention and control of essential hypertension.

Marine bivalves voucher DNA barcoding from Eastern Mediterranean, with evidence for Ostrea stentina invasion

Abstract Bivalve molluscs are a diverse group of animals with particular economic and ecological importance. Their morphological characteristics frequently confuse their identification leading to mislabelling of edible species. Genetic diversity is critical to the resilience of marine bivalve populations in the face of environmental stressors such as ocean acidification and warming. In this study, we characterized the phylogeny and defined the first DNA barcodes of six marine bivalves [Ostrea edulis (Linnaeus, 1758) Arca noae (Linnaeus, 1758), Pinctada radiata (Leach, 1814), Venus verrucosa (Linnaeus, 1758), Calllista chione (Linnaeus, 1758) and Ruditapes decussatus (Linnaeus, 1758)] sampled from different coastal areas of Aegean and Ionian Seas using the molecular markers cytochrome c oxidase subunit I (COI) and 18S ribosomal RNA (18S rRNA). Further, COI gene was employed to investigate the population genetic diversity since 18S rRNA exhibited no conspecific differences. The sequence of 18S rRNA successfully discriminated the bivalves at family or superfamily level but occasionally proved insufficient for species identification. Contrariwise, COI was highly informative and could reliably distinguish all species. Population haplotype diversity was moderate to high and was always accompanied by generally low nucleotide diversity, indicating genetically closely related haplotypes. The invasive Pinctada radiata was found to be panmictic even among distant sampling areas, while Ostrea edulis was the only species that exhibited moderate levels of population subdivision. Finally, here we report for the first time the presence of Ostrea stentina in Thermaikos Gulf sampled among Ostrea edulis specimens, demonstrating a new invasive bivalve species in Eastern Mediterranean.