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Genetic structure and selection signatures of Beijing-You chicken populations provide insight into breed conservation.

Preserving genetic diversity and maintaining population viability are critical yet challenging goals that demand rigorous evaluation of conservation strategies. Beijing-You chicken, as the sole indigenous chicken breed originating from Beijing, China, is currently maintained as four independent populations under distinct conservation programs. How different conservation regimes have shaped its genomic architecture remains largely unknown, limiting evidence-based evaluation. Here, we generated whole-genome resequencing data from 240 individuals representing four Beijing-You chicken populations to assess population structure, genetic diversity, and signatures of selection over decades of conservation. All four populations formed distinct clusters, reflecting measurable differentiation after decades of separate conservation. The differences in genetic diversity were broadly consistent with the variation in effective population size estimates. Runs of homozygosity and linkage disequilibrium decay patterns further characterized each population, with extended values indicating reduced effective population size and increased inbreeding under long-term conservation. We applied the fixation index (FST) and pairwise diversity ratio (θπ) methods to identify selection signatures. A total of 171 genes were identified as candidates. These genes were enriched in pathways related to reproduction, growth regulation, and environmental adaptation. These findings highlight patterns of reduced diversity and skewed relatedness, which could arise from management-related factors such as breeding preferences or mating strategies. Still, they are also compatible with neutral processes, including drift and founder effects. Regardless of the underlying cause, integrating scientifically informed conservation strategies with routine genomic monitoring across generations is essential for sustaining genetic diversity in Beijing-You chicken and other indigenous breeds.

Beijing-You chicken

Genome-wide scan for selection signatures in Mexican Sardo Negro Zebu cattle.

The Sardo Negro cattle (SN) is the only zebu cattle breed developed in Mexico. Since its development, the selection could have led to an increase in the homozygosity level in some regions of the genome and made differentiation with other cattle populations. We aimed to identify and characterize selection signatures in SN using medium-density SNP data using four approaches: 1) Runs of homozygosity (ROH) 2) Nucleotide Diversity 3) Tajima's D and 4) the Wright's fixation index (FST). A sample of 555 SN animals genotyped for 65k SNPs was used to obtain ROH segments considered regions under selection. The FST values were estimated by comparing the sample of genotyped SN animals with samples of genotyped animals from the Gir, Brahman, and Ongole breeds. Only one region mapped to 35.78-42.51 Mb on BTA6 was considered a selection signature by the ROH method. This selection signature overlapped with the lowest diversity, negative values of Tajima's D and a diversification region between SN and the other Zebu breeds by FST. We found several candidate genes (LCORL, NCAPG, and SLIT2) related to growth and other economically important productive traits in this common region. Using the FST method, different regions, such as regions on BTA8 (8:93.4-93.9 Mb), BTA11 (11:99.2-99.7), and BTA14 (14: 26.1-26.8) related to growth and milk traits also were defined as candidate selection signatures. The selective signals identified in this study reflected the direction of the selection pressure that primarily involves the increase of live weight traits in the Sardo Negro cattle breeding program.

Animals

Integrated Genome-Wide Association Studies and Selection Signature Analysis Reveal the Genetic Architecture of the Wattle Trait in Goats.

Wattles are finger-like appendages on the ventral neck of goats, serving as a distinctive morphological marker for breed identification that serves potential implications for production performance. However, their genetic basis remains incompletely characterized. Here, we integrated a genome-wide association study (GWAS) and selection signature analysis to identify candidate genes and genomic regions associated with the wattle trait in goats. Using a linear mixed model, GWAS on 463 goats (23 wattled and 440 non-wattled) identified 385 quantitative trait loci (QTLs) at a 5% false discovery rate, yielding 346 candidate genes. The most significant association signal was observed on chromosome 10 (72.61-73.48 Mb), where the lead SNP (rs636481767) is located within a region containing GJD2, GREM1, and FMN1, showing strong linkage disequilibrium (r2 > 0.6) with surrounding loci. Subsequent selection signature analysis (23 wattled and 23 non-wattled) identified 83 genomic regions harboring 119 candidate genes. The strongest signals were detected at MFSD14B on chromosome 8 (FST = 0.154, log2π-ratio = 2.611) and PDLIM7 on chromosome 7 (FST = 0.144, log2π-ratio = 0.806). KEGG pathway enrichment analysis revealed that GWAS-associated genes were involved in glycosylation and immune responses, whereas selection-signature genes were enriched in DNA repair and the Hippo, Notch, and Wnt pathways. Furthermore, cross-species PheWAS revealed that human FMN1 is associated with dermatological, skeletal, and metabolic phenotypes, while porcine FMN1 is associated with backfat thickness and loin muscle depth. Overall, this study provides molecular markers of potential value for goat breeding and pinpoints key candidate genes for future functional validation of wattle development.

Animals

Genomic diversity, inbreeding, and selection signatures in duroc, landrace, and yorkshire pigs from a long-term closed breeding system.

Duroc (DD), Landrace (LL), and Yorkshire (YY) are among the most widely used commercial pig breeds, having undergone intense long-term selection within closed breeding systems. This study presents a comprehensive genomic analysis of genetic diversity, inbreeding patterns, and selection signatures in DD, LL, and YY populations that have been subject to close breeding for over 15 years. Genomic and pedigree data were available for 1,088 animals (DD = 348, LL = 276, YY = 464), genotyped using the GenoBaits® Porcine 100 K SNP panel. Principal component analysis and genetic diversity metrics revealed distinct population structures among the three breeds. Pairwise genetic differentiation supported this pattern, with DD showing the greatest divergence from LL (0.34 ± 0.24) and YY (0.33 ± 0.24), while LL and YY were more closely related (FST = 0.22 ± 0.19). Linkage disequilibrium (LD) analysis further confirmed these differences, as DD exhibited the highest average r² (0.34), followed by LL (0.28) and YY (0.25). Within-breed genetic diversity metrics, including observed heterozygosity (HO: 0.37 in DD, 0.39 in LL, 0.38 in YY), expected heterozygosity (HE: 0.36 in DD, 0.37 in LL, 0.38 in YY), and minor allele frequency (MAF: 0.27 in DD, 0.28 in LL, 0.29 in YY), indicated greater genetic variability in LL and YY compared to DD. Runs of homozygosity (ROH) analyses revealed different patterns of autozygosity, with DD exhibiting more long ROH indicative of recent inbreeding, while YY harbored a higher number of short ROH, suggestive of more ancient demographic events. ROH-based inbreeding coefficients (FROH) consistently exceeded pedigree-based estimates (FPED) across all breeds, highlighting the presence of recent or unrecorded inbreeding that pedigree data may not fully capture. According to Generation Proxy Selection Mapping (GPSM), 17, 1, and 12 significant SNPs were detected in DD, LL, and YY, respectively. Functional annotation of ROH islands and GPSM-significant loci revealed both breed-specific and overlapping QTLs related to traits such as growth, reproduction, and carcass. In general, the findings of this study contribute to a deeper understanding of the genomic consequences of long-term closed breeding and provide reference information to support consideration of breeding strategies that balance continued selection for productivity with the maintenance of genetic diversity in modern commercial pig populations.

Animals

Whole-genome sequencing reveals divergent and shared selection signatures of heat stress adaptation in indigenous Ethiopian zebu cattle from dry-hot and humid-hot environments.

African zebu cattle (Bos indicus) exhibit remarkable adaptations to extreme thermal conditions, yet the genomic basis of this resilience remains incompletely characterized. Ethiopia provides a unique natural setting in which closely related zebu populations have adapted divergently to dry-hot (DHETZ) and humid-hot (HHETZ) climates. In this study, we reanalyzed publicly available whole-genome sequencing datasets from 46 Ethiopian zebu cattle from five populations and compared them with Asian zebu, Sudanese zebu, African taurine, and European taurine breeds. By integrating genome-wide SNP analysis, population genetic structure assessment, and multiple selection scans (iHS, Hp, XP-EHH, and XP-CLR), we identified distinct and shared selection signatures between DHETZ and HHETZ. We detected 33.7 million and 34.2 million biallelic autosomal SNPs in DHETZ and HHETZ, respectively. Ethiopian zebu clustered closely with Sudanese zebu but showed clear divergence from Asian zebu and taurine breeds. DHETZ and HHETZ exhibited very low genetic differentiation (FST = 0.0063), consistent with their shared ancestry; however, each group displayed unique selection signals. In DHETZ, iHS and Hp detected 298 and 113 candidate regions, respectively, whereas in HHETZ, they detected 244 and 138 regions, respectively. Cross-population XP-EHH and XP-CLR analyses identified 163 and 227 divergent regions between DHETZ and HHETZ, respectively. Integration of the four selection scans identified 19 high-confidence candidate regions in DHETZ and 13 in HHETZ. DHETZ showed strong selection in genes involved in oxidative stress regulation, protein folding, mitochondrial function, and vascular remodeling, including SESN2, DNAJC8, GRPEL2, ABLIM3, and AFAP1L1. In contrast, HHETZ displayed signatures in genes associated with immune responses, energy metabolism, and angiogenesis inhibition, including MYD88, PRKACA, PRKACB, and WIF1. Several genes, including VEGFC, TNIP3, and DMXL2, were under selection in both groups, suggesting conserved mechanisms of thermotolerance and reproductive adaptation. The shared VEGFC signal and the HHETZ-specific WIF1 signal may indicate a distinct vascular regulatory mechanism in the dry-hot and humid-hot environments. Our results reveal a dual pattern of genomic adaptation in Ethiopian zebu cattle and provide candidate loci for future validation and climate-resilient livestock breeding.

Animals

Genomic diversity and selection signatures in Asian Zebu Cattle: insights into adaptation and genetic erosion.

Indigenous cattle breeds in Asia are highly adapted to their local environments providing essential commodities such as meat, milk and draught power while also playing a key role in traditional ceremonies, and sports. Despite ongoing efforts to characterize and conserve these breeds, the increasing trend of indiscriminate crossbreeding of Zebu cattle with high-yielding taurine breeds, threatens their genetic diversity. This study investigates the population structure, inbreeding levels, effective population size, gene flow and identification of selection footprints of Asian Zebu (Bos indicus) cattle. Using an Axiom 60 K SNP chip, we analyzed genotypes from 1303 cattle across 36 populations in nine countries, including seven taurine outgroups and 29 Zebu populations from Bangladesh, Cambodia, India, Myanmar, Pakistan, and Sri Lanka. Zebu populations demonstrated moderate genetic diversity, with heterozygosity levels averaging 0.356, inbreeding coefficients ranging from 0.026 to 0.074 and genetic differentiation (FST) varied between 0.01 and 0.11. Breed clusters aligned closely with their geographic locations except for Achai (Pakistan) and Baru Harak (Sri Lanka) breeds that appeared in both Zebu and taurine clusters indicating evidence of taurine admixture. Genomic analyses identified regions under selection using extended haplotype homozygosity (EHH) and fixation index (FST) methods. Candidate genes associated with key biological functions related to environmental responsiveness, including heat tolerance (HSP90AA1), immunity (RIPK3), metabolism and fertility (REC8, CLIC4, TSSK4), were identified, reflecting adaptive traits critical for Zebu survival and utility across diverse environments. These findings provide valuable insights for conservation and management strategies aimed at preserving the unique genetic diversity of Asian Bos indicus breeds.

Animals

Whole-Genome Sequencing Reveals Population Structure, Genetic Diversity, and Selection Signatures in Kazakh Dromedary and Bactrian Camels.

Understanding the genomic basis of environmental adaptation is essential for the conservation and genetic improvement of domestic camels. In this study, we investigated the population structure, genetic diversity, and genomic variation potentially associated with environmental adaptation of Kazakh dromedary and Bactrian camels using whole-genome sequencing. Whole-genome sequencing data were generated for Kazakh camels (15 dromedaries and 16 Bactrian camels) and integrated with 131 publicly available genomes representing camel populations from the Arabian Peninsula, Iran, Xinjiang, Inner Mongolia, and Mongolian wild camels. Population structure, genetic diversity, and genome-wide selection were evaluated using principal component analysis, ADMIXTURE, nucleotide diversity, linkage disequilibrium, runs of homozygosity, genomic inbreeding (FROH), and selection scans based on FST, θπ ratio, and XP-EHH. Population genomic analyses revealed clear differentiation between dromedary and Bactrian camels, whereas Kazakh camel populations exhibited higher nucleotide diversity (θπ = 1.307-1.551 × 10-3), and lower genomic inbreeding (median FROH: 0.037-0.056) than Arabian populations. Genome-wide selection analyses identified MC4R as the prominent candidate gene in Kazakh dromedaries and RYR1 as a prominent candidate gene in Kazakh Bactrian camels. Functional enrichment analyses highlighted pathways related to energy metabolism, thermogenesis, calcium signaling, skeletal muscle function, mitochondrial activity, and oxidative stress response. These findings provide new insights into genomic variation potentially associated with environmental adaptation in Kazakh camels and offer valuable genomic resources for future conservation, breeding, and evolutionary studies.

MC4R

Whole-genome sequencing identifies genetic diversity and adaptive signatures of hypoxia and ultraviolet radiation in Chinese chickens.

INTRODUCTION: Domestic chickens primarily descended from the wild red junglefowl, play a crucial role in global egg and meat production. China hosts diverse indigenous chicken populations that have adapted to various environmental conditions, including high-altitude with hypoxic and ultraviolet radiation stress. METHOD: We analyzed whole-genome sequences of 118 birds from five Indigenous Chinese chicken populations and 295 chicken genomes from publicly available databases to identify genomic diversity, admixture, and selection signatures of chickens adapted to high-altitude environments. Selection signatures were identified using nucleotide diversity (π), Tajima's D, XPEHH, and XP-CLR, selection scan methods. RESULTS: We observed a reduction in genetic diversity and historical declines in effective population size in high-altitude chicken, suggesting ongoing selection pressures shaping these populations. Selection scans identified nine genomic regions under strong positive selection, enriched for genes associated with hypoxia and ultraviolet radiation. Notably, five genes (TPK1, BAZ2B, MARCHF7, LLGL2, and RCAN3) were repeatedly detected across multiple selection signature analyses. RNA-seq analysis further confirmed the differential expression of these genes in the lung and heart tissues of chickens adapted to high and low altitudes, reinforcing their role in physiological adaptation to hypoxic environments. Altitude adaptation is driven by the selection of genes involved in oxygen metabolism, cellular stress response, and energy regulation. CONCLUSION: Our study provides compelling genetic evidence for differentiation between high and low and high-altitude Chinese chicken populations. These findings also ensure our understanding of local adaptation in poultry and establish a genomic framework for breeding strategies to improve environmental resilience to altitude-related stressors.

Animals

Large-scale low-coverage whole-genome sequencing reveals the genetic architecture of wool and growth traits in fine-wool sheep.

Breeding sheep with superior growth performance and wool quality is essential for the sustainability of the fine-wool sheep industry. In this study, we perform low-coverage whole-genome sequencing (lcWGS) on 3842 individuals from 5 sheep breeds (4 fine-wool and 1 semi-fine wool) and generate a large genomic dataset. By comparing these breeds with coarse-wool sheep, we characterize the genomic landscape and selection signatures of fine-wool sheep. We identify several known functional genes associated with hair follicle development and skin morphology, including EGFR, KRT74, EDAR, EREG, and GLI2. Furthermore, GWAS of 19 traits identifies 156 candidate genes significantly associated with growth and wool characteristics, including LCORL for body size, EGFR for clean wool yield, and PRDM1 for fiber diameter. Notably, EGFR is detected in both GWAS and selection signature analyses, indicating its important role in phenotype formation and historical selection. Overall, our findings reveal the genetic basis of growth and wool traits in fine-wool and semi-fine wool sheep, highlight EGFR, LCORL, and PRDM1 as candidate genes, and provide valuable genomic resources and candidate markers for future functional validation and molecular breeding.

Body size

Human biopsy-defined ischemia-reperfusion injury-selective reperfusion signature prioritizes reperfusion-timed mitogen-activated protein kinase kinase inhibition after donation after circulatory death liver transplantation.

Early post-liver transplant ischemia-reperfusion injury (IRI) in donation after circulatory death grafts lacks therapies targeted to the immediate postreperfusion window, in part because generic reperfusion transcription obscures IRI-selective amplification. We analyzed paired prereperfusion/postreperfusion liver biopsies from 2 cohorts (GSE151648 and GSE87487) using a difference-in-differences interaction estimand (&#x394;&#x394; = [Post-Pre]IRI+ - [Post-Pre]IRI-) to define an IRI-selective early reperfusion program. Genome-wide &#x394;&#x394; effects were summarized using pathway-responsive genes, and pathway concordance was tested using permutation (B = 5000). The reproducible &#x394;&#x394; footprint highlighted epidermal growth factor receptor-mitogen-activated protein kinase signaling (Spearman &#x3c1; = 0.811; P = .001). Directional &#x394;&#x394; gene sets (interaction P < .05) were submitted to the L1000 characteristic direction signature search engine2; cross-cohort overlap identified 8 shared perturbagens, including 3 mitogen-activated protein kinase kinase (MEK)1/2 inhibitors. In a hepatic ischemia/reperfusion time course (GSE117915), epidermal growth factor receptor and mitogen-activated protein kinase activities increased within 0.5 hours of reperfusion, and transplant single-cell RNA sequencing (GSE189539) localized MEK/extracellular signal-regulated kinase pathway engagement predominantly to parenchymal cells. A representative MEK inhibitor, PD-0325901, reduced hepatocyte oxygen-glucose deprivation/reoxygenation injury and, when administered at reperfusion in a rat donation after circulatory death liver transplantation model (5-20 mg/kg), attenuated histologic and biochemical injury, apoptosis, and redox-inflammatory readouts and improved 7-day survival. Collectively, this biopsy-anchored &#x394;&#x394; interaction-phenotype framework, with cross-cohort concordance as a prespecified robustness gate, nominates reperfusion-timed MEK inhibition as a mechanism- and window-aligned strategy to blunt early post-liver transplant IRI.

difference-in-differences (time &#xd7; IRI interac

Genome-Wide Differentiation, Inbreeding, and Candidate Selection Loci in Local Vietnamese Pig Breeds.

Vietnam harbors exceptional genetic diversity among at least 26 indigenous pig breeds. We analyzed genome-wide single-nucleotide polymorphism (SNP) data from 90 animals representing 15 local Vietnamese breeds and six Landrace pigs using principal component analysis, the windowed fixation index (FST), cross-population extended haplotype homozygosity (XP-EHH), within-population integrated haplotype score (iHS), and runs of homozygosity (ROHs). The population structure was consistent with a north-south differentiation axis, and Ba Xuyen showed elevated heterozygosity, providing suggestive evidence of a European genetic contribution; the f3 statistic was positive (f3 = +0.015), and formal evidence of admixture requires a significantly negative f3, so this criterion was not met. Integration of FST and XP-EHH identified GPC5, E2F6, NOS1, and TLR4 as top Northern candidate loci and CRYM/ZP2 as the leading Central candidate locus, and these windows were recovered at both the 90th and 95th percentile thresholds, indicating analytical robustness rather than independent biological validation. iHS was elevated at E2F6 in Northern breeds (|iHS| = 3.04) and at NOS1 across all regional groups (|iHS| = 2.66-3.36). Breed-level phenotypic XP-EHH, based on published breed descriptions and coat color rather than individual body-composition measurements, identified GALNT2 as a candidate shared across breed groups; HCAR1 and ATG10 as candidates specific to the extreme-fat/prolific breed group; and EFNA5 and HIPK2 as candidates specific to the medium-bodied breed group. ROHs identified Soc, Co, and Hung as breeds warranting particular attention in conservation planning due to elevated autozygosity. Because each breed was represented by only six individuals, and because no individual-level phenotypic measurements were available, all findings are reported as exploratory population-genomic signals requiring replication in larger cohorts. Overall, we describe genomic differentiation and candidate selection signatures among local Vietnamese pig breeds and provide a foundation for further genomic studies of these breeds.

Animals

The Jumonji C domain-containing proteins GmJMJ19 and GmJMJ20 link florigen signaling with epigenetic regulation of photoperiodic flowering and post-flowering plant height in soybean.

Soybean (Glycine max) is a photoperiod-sensitive legume whose latitudinal adaptation depends on the precise control of flowering time and plant height. Histone demethylases of the JmjC domain-containing (JMJ) protein family have been implicated in these processes across plant species, but their specific roles in soybean remain largely unexplored. Here, we identify soybean GmJMJ19 and GmJMJ20, two closely related JMJD5/KDM8 orthologs, as master epigenetic regulators that coordinately control both photoperiodic flowering and post-flowering plant height. Both genes exhibit intrinsic, rhythmic expression peaking at ZT12, and their encoded proteins physically interact with the florigen proteins FT2a and FT5a. Loss-of-function mutants display delayed flowering under long days (LDs) and increased plant height under both LDs and short days (SDs), whereas overexpression phenocopies the mutant flowering phenotype, indicating revealing a critical dosage requirement for proper function. Mechanistically, GmJMJ19 and GmJMJ20 are recruited by the FT/FD transcriptional complex to directly activate AP1a and AP1c expression through chromatin modulation. Population genomic analyses reveal distinct selection signatures: GmJMJ19 underwent sustained directional selection during cultivation, whereas GmJMJ20 experienced an early domestication sweep with limited subsequent change. Haplotype analysis identifies coordinated latitudinal clines, with the JMJ19H1/JMJ20H1 combination predominating at high latitudes to promote early flowering and limit height, while JMJ19H2/JMJ20H2 and wild JMJ19H3/JMJ20H3 alleles prevail at low latitudes, conferring later flowering and increased height. Collectively, our findings establish GmJMJ19 and GmJMJ20 as central chromatin regulators linking florigen signaling to downstream target expression and provide valuable allelic resources for breeding regionally adapted soybean varieties across a wide range of latitudinal environments.

Histone modulation

Effects of domestication on the body morphology and genetic diversity of the yellowfin seabream (Acanthopagrus latus).

The yellowfin seabream (Acanthopagrus latus) is a significant economic fish along the southeast coast of China. Recently, the drastic decline in the wild populations, exacerbated by overfishing and climate change, has heightened our reliance on aquaculture. However, the current lack of research on its domestication hinders effective conservation of wild populations and balanced management alongside the aquaculture industry. Studies on body characteristics have shown that wild yellowfin seabream possess a higher body, while cultured ones exhibit a wider body. Whole-genome SNP analysis revealed moderate genetic differentiation between cultured and wild populations. Further analyses of linkage disequilibrium, heterozygosity, and genetic diversity revealed that the degree of SNP linkage was lower in the wild population compared to the cultured population. In contrast, heterozygosity and nucleotide polymorphisms were significantly higher in the wild population (P&#xa0;<&#xa0;0.001 and P&#xa0;<&#xa0;0.05, respectively). Additionally, over 300 candidate genes were identified in each cultured population through genomic selection signature analysis, with 67 key genes shared among all three, which were linked to growth and development (ghrb, ghsra, and cfl1), immune response (aire, cd36, and igbp1), and salinity adaptation (abcc3, clic4, and kcnk15). Enrichment analysis indicated that the key candidate genes were significantly enriched in pathways related to protein kinase activity, ion binding and growth hormone synthesis, secretion and action (FDR&#xa0;<&#xa0;0.05). The findings provide valuable insights into the variation in body size of yellowfin seabream under domestication selection and offer an important theoretical basis for the genetic improvement of yellowfin seabream.

Animals

Genome Wide Analysis Reveals Divergence and Ancestral Origins of Min Pigs.

The Min pig, a representative northern Chinese indigenous breed, carries a unique ancestral background shaped by the historical phylogeography of Northeast Asia. This study aimed to dissect the population structure, temporal genetic divergence, and ancestral composition of Min pigs, trace their evolutionary origin, and identify trait-linked functional genes, providing information regarding their evolutionary history and conservation. We analyzed 61 Min pigs sampled across nearly 20&#x2009;years and 701 reference pigs comprising other Chinese indigenous breeds, Western commercial lines, and Chinese wild boars, using PCA, NJ phylogenetic analysis, Admixture, TreeMix, D-statistic, f4-ratio, and combined selection signature scans (sliding-window FST, XP-EHH, and &#x3c0;-ratio). Clear genetic stratification was observed among Min pig subpopulations, reflecting long-term divergence under natural and artificial selection. PCA and Admixture (K&#x2009;=&#x2009;2-4) separated East Asian indigenous and Western ancestral components, verifying an admixed Northeast Asian origin with a dominant ancient East Asian component and a Western component. Compared with early-2000s Min pigs, contemporary individuals are genetically closer to Western breeds and exhibit a more scattered structure due to shifted ancestral component proportions, further confirmed by D-statistic and f4-ratio values. We identified 321 differentiated SNP loci based on the Animal QTL database, corresponding to core candidate genes (AKT3, ACACA, MAP3K5, FGFR4, C3, and SERPINC1) enriched for meat quality, growth, reproduction, immunity, energy metabolism, and MAPK/PI3K-Akt/AMPK pathways. This study reveals Min pigs' admixed origin and temporal divergence, clarifying their Northeast Asian evolution and providing molecular markers for genetic monitoring and conservation.

Animals

MWENA: a novel sample re-weighting-based algorithm for disease classification and data interpretation using extracellular vesicles omics data.

BACKGROUND AND OBJECTIVE: Extracellular vesicles (EVs), considered as a form of liquid biopsy, have gained significant attention in recent years due to their stability and the preservation of disease markers. Research studies underscore the clinical significance of molecules found in EVs, highlighting their role as communicative mediators between cells. However, analyzing this data is challenging due to noisy measurements, having far more variables than samples, and some groups (e.g., disease subtypes or experimental conditions) having much less data than others. We therefore develop an algorithm to address aforementioned challenges for the classification of imbalanced EVs omics data. METHODS AND RESULTS: We propose the EV Meta-Weight Elastic Net Algorithm (MWENA), which utilizes logistic regression with elastic net regularization for the classification and identification of EV signatures, effectively addressing the challenges posed by high-dimensional small sample sizes. To mitigate issues related to class imbalance and high noise levels, MWENA incorporates an automatic sample re-weighting function, which uses a meta-net to adaptively learn generalizable patterns directly from the data itself. We validate the MWENA algorithm on both simulated data and EVs omics data, covering six classification tasks that involve four different types of diseases (pancreatic ductal adenocarcinoma, interstitial lung diseases, colorectal cancer, and ovarian cancer) and three clinical scenarios (disease diagnosis, disease-stage screening, and disease-subtype classification). Compared to other machine learning methods, MWENA demonstrates superiority in identifying small class samples and achieves the highest scores in both sensitivity and G-means. Biological analysis is also performed to further explore the significance of selected signatures as biological markers and their roles in disease mechanisms. CONCLUSIONS: We anticipate that our proposed approach will take a modest step in harnessing EV omics data to discover biomarkers, aiding researchers in gaining a comprehensive understanding of biological processes.

Extracellular Vesicles

Genomic insights into the population history of fat-tailed sheep and identification of two mutations that contribute to fat tail adipogenesis.

INTRODUCTION: Since their domestication, domestic sheep (Ovis aries) have been culturally and economically significant farming animals worldwide. Fat-tailed sheep serve as a unique genetic resource for understanding adipogenesis and adaptive evolution in livestock. OBJECTIVES: Several genomic analyses have been conducted on various sheep breeds to elucidate the genome and regulation mechanism of the fat tail trait, prior genomic studies have failed to reconcile conflicting evidence about the genetic basis of tail morphology, particularly regarding the roles of PDGFD and BMP2. METHODS: Here, we conducted whole-genome resequencing of 283 sheep, encompassing 66 domestic breeds and 5 wild ovine species, to investigate the domestication history and selection signatures of fat-tailed sheep. Additionally, we performed transcriptome sequencing on adipose tissue to identify differentially expressed genes and cellular assays to validate these results. RESULTS: Demographic analysis revealed that domestic sheep descended from Asiatic mouflon and fat-tailed sheep began to diverge from thin-tailed sheep approximately 4.4-7.5 thousand years ago in East Asia. Chinese indigenous sheep were classified into Mongolian, Kazakh, Tibetan, and Yunnan populations. The Yunnan population may have experienced more recent genetic introgression from wild species, rather than an independent domestication event. Moreover, many potential regions associated with the fat-tailed phenotype (DDI1, PDGFD, and BMP2) were identified by selective sweep and genome-wide association analyses. Additionally, a fine-scale analysis of fat-tailed and thin-tailed sheep revealed two novel mutations: a G/A missense variant of PDGFD (Chr15: 3900312) and a C/T missense variant of BMP2 (Chr13: 48462350), both of which were significantly associated with tail adiposity. Functional validation demonstrated that mutant A-PDGFD significantly activated PFGFD expression and reduced fat deposition compared to wildtype. The C-BMP2 mutant activated BMP2 expression and promoted preadipocyte fat deposition. CONCLUSION: Our study provides the first evidence that these genes jointly regulate fat tail development through complementary mechanisms: PDGFD promotes adipose expansion, whereas BMP2 modulates energy partitioning. These findings offer new insights into the evolutionary history of fat-tailed sheep and identify potential targets for precision breeding in small ruminants.

Animals

LCORL and STC2 Variants Increase Body Size and Growth Rate in Cattle and Other Animals.

Natural variants can significantly improve growth traits in livestock and serve as safe targets for gene editing, thus being applied in animal molecular design breeding. However, such safe and large-effect mutations are severely lacking. Using ancestral recombination graphs, we investigated recent selection signatures in beef cattle breeds, pinpointing sweep-driving variants in the LCORL and STC2 loci with notable effects on body size and growth rate. The ACT-to-A frameshift mutation in LCORL occurs mainly in central-European cattle, and stimulates growth. Remarkably, convergent truncating mutations were also found in commercial breeds of sheep, goats, pigs, horses, dogs, rabbits, and chickens. In the STC2 gene, we identified a missense mutation (A60P) located within the conserved region across vertebrates. We validated the two natural mutations in gene-edited mouse models, where both variants in homozygous carriers significantly increase the average weight by 11%. Our findings provide insights into a seemingly recurring gene target of body size enhancing truncating mutations across domesticated species, and offer valuable targets for gene editing-based breeding in animals.

Animals

Genetic diversity of Plasmodium falciparum helical interspersed subtelomeric (phistb) gene in Tanzania and neighboring countries.

BACKGROUND: Lysine-rich membrane associated Plasmodium helical interspersed subtelomeric gene (phistb) is a member of the phist family of genes which encodes exported proteins essential for the parasite's survival within infected red blood cells. Recent studies suggest the phistb gene as a promising malaria vaccine candidate, however, its genetic diversity remains understudied. This study assessed the genetic diversity of the phistb gene in regions of varying malaria transmission aiming to generate data and improve our understanding of this promising malaria vaccine candidate gene. METHODS: Genomic data from 1472 Plasmodium falciparum samples from Tanzania, Kenya, Uganda, and Ethiopia were retrieved in variant Calling file format (VCF) format from the MalariaGEN Pf7 database. Variants were filtered to include only biallelic Single Nucleotide Polymorphism (SNPs) with Variant Quality Score Log- Odds (VQSLOD)&#x2009;>&#x2009;1 and "PASS" status. Genetic diversity, differentiation, and selection signatures were analyzed using population genetics metrics. RESULTS: After filtering, 1312 samples were retained. Wright's inbreeding coefficient (Fws) showed that 875 (66.7%) samples had monoclonal infections, with the highest proportion of monoclonal infections in Ethiopia (95.3%), followed by Tanzania (67.2%), Kenya (65.7%), and Uganda (50%). Among the 875 monoclonal samples, 88 haplotypes were identified, with Hap_1 (renamed PF3D7)&#xa0;and Hap_13 comprising 37.9 and 21.5 of the samples, respectively. Nucleotide and haplotype diversity were relatively higher in Kenya with 0.097, and 0.88 respectively, compared to the other study populations. The overall fixation index (Fst) was&#x2009;<&#x2009;0.05, and Principal Component Analysis revealed no clear population sub-structure among countries. Negative Tajima's D values in Tanzania, Kenya, and Ethiopia indicated an excess of low-frequency alleles. CONCLUSION: This study reports low genetic diversity of the phistb gene in the four countries despite varying malaria transmission intensities among them, thus making it a suitable candidate gene for malaria vaccine. Further studies should be conducted to assess individual antibodies recognition of the phistb variants and the ability to elicit cross reactivity to further support its potential as a vaccine candidate.

Plasmodium falciparum