Search Results (138)

Background/Objectives: The domestic yak (Bos grunniens) is a livestock species of major relevance in high-altitude environments and an important model for studying adaptation and reproductive isolation within Bovini. Despite its close phylogenetic relationship with cattle (Bos taurus), yak × cattle hybrids show a marked sex-biased fertility pattern, with fertile females and generally sterile F1 males, suggesting that subtle chromosomal or genomic differences may underlie post-zygotic reproductive barriers. In this study, we performed a cytogenetic characterization of eight adult yak bulls imported and reared in Central Italy using conventional and molecular cytogenetic approaches. Results: GTG-, RBG-, RBA- and CBA-banding confirmed the yak diploid number as 2n = 60 and the fundamental number as NF = 62, with banding patterns highly comparable to the standardized cattle karyotype. CBA-banding showed an X chromosome lacking evident constitutive heterochromatin and a Y chromosome with distal C-positive blocks. Chromosome instability was low, with 3.75% abnormal metaphases, mainly represented by chromatid and iso-chromatid breaks, while the mean sister chromatid exchange (SCE) rate was 5.19 ± 2.14 per cell. Sequential Ag-NOR/RBA staining localized nucleolar organizer regions (NORs) at the telomeres of autosomes 2, 3, 4, 11 and 25, as in cattle. Zoo-FISH using bovine chromosome paints for X, Y, 5 and 15 showed complete hybridization to the corresponding yak chromosomes, and BAC-FISH mapped the Y-linked ZFY and SRY genes to positions homologous to those reported in cattle. A comparative bioinformatics analysis of available yak genome assemblies confirmed the overall genome-wide correspondence with cattle, while revealing chromosome orientation issues and small local inconsistencies that may be relevant for comparative mapping and probe design. Conclusions: Overall, at the resolution tested, these findings support broad macrostructural conservation of yak and cattle karyotypes and provide cytogenetic reference data for yak populations reared outside of their traditional range. The persistence of F1 male sterility despite this large-scale chromosomal conservation suggests that fine-scale sex chromosome differences, particularly involving pseudoautosomal regions, recombination boundaries, or heterochromatin organization, may deserve targeted investigation. Full article

Rana dybowskii is an economically important amphibian in Northeast China, valued for its medicinal oviduct (Oviductus Ranae). However, the low proportion of females in artificial culture severely restricts industrial productivity. To elucidate the molecular mechanisms of hormone-induced sex reversal, based on our previous research results, we exposed tadpoles to 17β-estradiol (E₂) or testosterone propionate (TP). We then monitored gonadal histology, conducted multi-stage transcriptome sequencing, and validated key genes via qRT-PCR. The results show that induction treatment with 40 μg·L⁻¹ E₂ and 80 μg·L⁻¹ TP resulted in 93.33% female and 100% male populations, respectively. Both hormones promoted germ cell proliferation at the undifferentiated stage and directed stable ovarian or testicular development without intersex abnormalities. Ovarian differentiation involved progressive multi-wave transcriptional reprogramming, whereas testicular differentiation exhibited a concentrated gene expression burst during gonadal maturation. Steroid hormone biosynthesis, Wnt, and PPAR pathways formed the core regulatory network. Three female-biased genes (3α-hsd, Adcy3, Rspo1) and three male-biased genes (Ptgs2, Sox9, Shbg) were identified, with their expression dynamics aligned with histological progression. This study defines the optimal parameters and molecular signatures of bidirectional sex reversal in R. dybowskii. It provides a practical foundation for sex-control breeding and offers amphibian-based evidence for the conservation and plasticity of vertebrate sex determination. Full article

The rapid growth of avian genomic resources has created a field rich in genomic data but still in need of integrative synthesis. Here, we review evidence linking four colour-producing systems—melanin, carotenoids, psittacofulvins and structural colouration—to feather development and evolutionary change. Melanin output is shaped by the MC1R–ASIP–MITF regulatory axis, melanogenic enzymes and the local availability of substrates such as cysteine. Carotenoid colouration depends on dietary uptake, SCARB1-mediated transport, BCO2-regulated precursor availability and, in many red species, CYP2J19-mediated ketolation acting with BDH1L; however, CYP2J19-independent red routes demonstrate that similar colour phenotypes can evolve through different molecular solutions. Structural colours arise from feather nanostructures and may interact developmentally with pigment deposition, whereas psittacofulvins represent an independent pigment system in parrots. We also discuss sex-biased gene expression, feather-region specificity, environmental sensitivity and lineage-specific regulatory change. Overall, avian plumage colour evolution is shaped by conserved biochemical and developmental constraints, yet similar colour phenotypes can arise through different regulatory, metabolic or structural routes. Full article

Sex is an important biological variable in animal physiology and environmental-stress research, but its influence on fish intestinal transcriptomic profiles remains insufficiently characterized. In this study, adult female and male Mugilogobius chulae were used to characterize baseline intestinal sex differences and to evaluate their relevance to short-term sulfamethoxazole exposure. Fish were assigned to solvent control or nominal 1 mg/L sulfamethoxazole exposure for 7 days, and intestinal tissues were analyzed by histology, RNA sequencing (RNA-Seq), functional enrichment analysis, gene set enrichment analysis, and quantitative real-time polymerase chain reaction validation. Representative histological sections showed qualitative sex-related differences in intestinal morphology. Transcriptomic analyses revealed that intestinal variation was more strongly associated with sex than with pooled treatment status. The pooled female-versus-male comparison identified 85 differentially expressed genes, whereas the pooled treatment-versus-control comparison yielded no significant differentially expressed genes under the current threshold. Functional enrichment and gene set enrichment analyses showed that female-biased intestinal profiles were mainly associated with nutrient absorption, lipid and sterol handling, membrane transport and epithelial interface-related pathways, whereas male-biased profiles were more closely related to RNA processing, oxidative metabolism, translation, protein targeting and mucosal immune signaling. These findings demonstrate sex-dependent intestinal transcriptomic signatures in M. chulae and support sex-aware intestinal transcriptomic analysis in aquatic animal omics and environmental-stress evaluation. Full article

Primordial germ cells (PGCs) are the earliest precursors of gametes and essential cellular materials for poultry germplasm conservation and genetic modification. In this study, PGCs isolated from 2.5-day male and female Silkie chicken embryos were defined as circulating PGCs (cPGC_M and cPGC_F), whereas PGCs isolated from 8.5-day male and female embryos were defined as gonad-derived PGCs (gPGC_M and gPGC_F). RNA sequencing with three biological replicates per group was performed to characterize developmental-stage- and sex-associated transcriptional programs. Comparative transcriptomic analyses identified stage-associated differences in pathways related to cell–matrix interaction, focal adhesion, PI3K–Akt signaling, and stem cell pluripotency, with more differentially expressed genes detected in the female than in the male stage comparison. Sex-biased expression was detectable at the circulating stage, mainly reflecting W- and Z-linked expression differences, and the number of sex-biased genes was greater after gonadal colonization, primarily because more autosomal differentially expressed genes were detected. Candidate genes and pathways, including HINTW, DMRT1, SOX2, EDNRB, LPAR4, GFRA3, ECM–receptor interaction, ribosome-related modules, and calcium signaling, were associated with these comparisons and are presented as targets for future validation rather than as confirmed regulators. Because the study used three biological replicates per group, RT-qPCR corroboration was limited to six female stage-associated genes, and no functional perturbation assays were performed, the findings are descriptive and do not establish causal mechanisms of PGC migration, gonadal colonization, or sex differentiation. Within these limitations, the dataset provides an exploratory resource for subsequent studies of chicken PGC biology and biotechnology. Full article

Rhinogobio nasutus, an endangered fish species endemic to the upper and middle reaches of the Yellow River in China, lacks essential genomic information on gonadal development, hindering research into its reproductive biology. To address this, mRNA-seq and miRNA-seq datasets derived from adult testis (n = 3) and ovary (n = 3) were integrated to characterize sex-biased expression profiles and potential regulatory mechanisms. A total of 34,813 genes and 68,623 transcripts were detected, and 16,105 differentially expressed genes (DEGs) were identified between testis and ovary, including 9365 testis-biased and 6740 ovary-biased genes. Small-RNA profiling identified 51 differentially expressed miRNAs (DEMs: 31 testis-biased; 20 ovary-biased). The sex-biased mRNA profiles highlighted conserved candidate genes associated with germ-cell maintenance, somatic regulation, ovarian differentiation, and oocyte maturation, including vasa, piwi, dmrt1, amh, cyp19a1a, zar1, zar1l, and rbpms2. Integrated miRNA–mRNA analysis further predicted potential interactions involving key sex-related genes, suggesting that DEMs may contribute to post-transcriptional regulation during gonadal differentiation. Functional enrichment (GO and KEGG analyses) highlighted pathways associated with gonadal differentiation, germline maintenance, and signal transduction pathways. qRT-PCR validation of nine mRNAs and nine miRNAs showed expression patterns consistent with the sequencing results. Collectively, these results provide an integrated mRNA and miRNA resource for R. nasutus gonads and identify candidate genes and miRNAs for future studies on sex-biased gonadal development, reproductive regulation, and artificial propagation. Full article

The northern pike (Esox lucius) is an economically important cold-water fish species in northern China. It exhibits pronounced sexual dimorphism, yet the molecular mechanism underlying its sex differentiation remains unclear, which hinders the development of aquaculture. Whole-transcriptome sequencing is a powerful approach for screening sex-related genes; however, no such study has been reported for this species to date. In this study, gonadal tissues from three female and three male E. lucius were collected for whole-transcriptome sequencing. A total of 14,941 differentially expressed messengerRNAs, 119 differentially expressed microRNAs, 229 differentially expressed circularRNAs, and 2055 differentially expressed long non-codingRNAs were identified. Functional enrichment analysis revealed that the differentially expressed genes were significantly enriched in pathways closely associated with sex differentiation, such as steroid hormone biosynthesis and oocyte meiosis. Several key sex-biased genes were identified, including female-biased genes (FANCL, DDX5, SRSF5B) and male-biased genes (STAR, FDX1B, ITGA2B). Furthermore, a competing endogenous RNA (ceRNA) regulatory network involving dre-miR-107b was constructed, which may represent a candidate for further investigation into sex differentiation in E. lucius. This study provides the first comprehensive whole-transcriptome dataset of female and male gonads in E. lucius, identifies key sex-biased genes and core pathways involved in its sex differentiation, and thereby identifies the dre-miR-107b-centered ceRNA network and key sex-biased genes (FANCL, DDX5, SRSF5B, STAR, FDX1B, ITGA2B) as core molecular players in sex differentiation of this species. Full article

The brown frog (Rana dybowskii) is an important cold-temperate amphibian species in northeastern China, with considerable ecological and resource value. Because its survival, metabolism, and reproduction are highly sensitive to environmental temperature, elucidating the molecular mechanism’s underlying temperature response is of great significance for understanding environmental adaptation and reproductive regulation in amphibians. In this study, R. dybowskii was used as the experimental model, and a multi-tissue transcriptomic analysis was conducted on the brain, liver, spleen, ovary, oviduct, and testis from both females and males under 2 °C and 12 °C conditions to characterize tissue- and sex-specific responses to temperature variation. The results showed that the global transcriptomic landscape of R. dybowskii was primarily driven by tissue type, whereas temperature effects were mainly manifested within individual tissues. The liver, brain, and spleen exhibited pronounced temperature responsiveness in both sexes, with the liver mainly showing metabolic reprogramming-related functional changes. Intersection analysis further revealed that temperature-responsive genes included not only conserved modules shared across tissues but also a large number of tissue-specific genes. Reproductive tissues displayed more pronounced functional divergence: the ovary showed relatively limited transcriptional changes and remained comparatively stable; the oviduct underwent marked transcriptional remodeling, with upregulated genes mainly involved in glycosylation and macromolecule processing, whereas downregulated genes were primarily associated with ribosomes, translation, and RNA splicing; the testis was likewise highly sensitive to temperature changes, with upregulated genes mainly enriched in amino acid metabolism, mitochondrial function, and DNA repair, while downregulated genes were mainly related to cellular structure and intercellular junctions. Collectively, these findings indicate that the molecular adaptation of R. dybowskii to temperature variation is characterized by strong tissue specificity and sex-biased responses in reproductive tissues. This study provides a transcriptomic basis for elucidating the molecular responses to short-term temperature variation is important for understanding environmental sensitivity and reproductive regulation in amphibians. Full article

Chinese tongue sole (Cynoglossus semilaevis), an economically important mariculture species in China, exhibits pronounced sexual dimorphism in growth, underscoring the importance of elucidating sex regulatory mechanisms for aquaculture development. Heterogeneous nuclear ribonucleoprotein K (hnrnpk) critically regulates mammalian reproductive development, yet its role in fish sex regulation remains elusive. Here, we systematically investigated the underlying function and mechanisms of hnrnpk in C. semilaevis through integrated molecular cloning, expression profiling, upstream regulatory analysis, functional assays, and transcriptome sequencing. We found that hnrnpk was highly expressed in the gonad and liver, with female-biased expression during gonadal development. Promoter activity assays revealed that sox2 and c-Jun enhanced hnrnpk transcription, whereas foxl2 and ar suppressed it. Additionally, hnrnpk was directly targeted by miR-460a-5p in C. semilaevis, revealing multi-level transcriptional and post-transcriptional regulation. Functional analyses showed that hnrnpk regulated cyp19a1a in a cell type-dependent and dose-sensitive manner: the expression of cyp19a1a was both upregulated in hnrnpk-knockdown ovarian cells and hnrnpk-overexpression testicular cells. Interestingly, foxl2 was upregulated in hnrnpk-knockdown ovarian cells but suppressed in hnrnpk-overexpression testicular cells, which showed the distinct regulation mechanisms in the different sexual programs. Transcriptomic analyses further revealed that several sex-related genes (sox9a with downregulation, etc.) were significantly regulated, and cell development and cycle pathways were dramatically enriched in functional enrichment analyses. This might indicate that hnrnpk overexpression drives C. semilaevis testis (CSTE) toward feminization reprogramming through sox9 switching and multi-pathway perturbations. Overall, our findings might reveal that hnrnpk, a female-biased gene regulated by miR-460a-5p and transcription factors, influences sex-related gene expression through sox9 switching. This study will offer new insights for C. semilaevis hnrnpk into sex determination and also provide a potential target for monosex breeding in aquaculture. Full article

Background/Objectives: Neuritogenesis and synaptogenesis support learning and cognitive function, and hippocampal neurons play central roles in these processes. Cleistocalyx nervosum var. paniala (CNP), a Southeast Asian berry, has reported neuroprotective activities, but its direct effects on hippocampal neurons remain unclear. We investigated whether CNP extract modulates hippocampal neuronal transcriptomes, neuritogenesis, and synaptogenesis. Methods: Primary hippocampal neurons isolated from male and female Wistar rat pups were treated with CNP extract in vitro. Cytotoxicity was assessed to define non-cytotoxic concentrations. Transcriptomic responses were profiled by RNA sequencing and validated by RT-qPCR. Neuritogenesis was quantified by neurite morphology and Sholl analysis. Synaptogenesis was evaluated by synaptic immunocytochemistry. Molecular docking of cyanidin-3-glucoside (C3G) and resveratrol was used to generate mechanistic hypotheses. Results: At 0.1–10 µg/mL, CNP was non-cytotoxic, whereas a 100 µg/mL dose reduced viability; therefore, 10 µg/mL was used in subsequent experiments. Exploratory RNA-seq profiling identified thousands of differentially expressed genes enriched in synapse- and neurite-related pathways, including synaptogenesis signaling, axon guidance, and neuritogenesis. RT-qPCR showed upregulation of Igf1 in males and Glul in females, with sex-dependent modulation of Bdnf and Cask. CNP increased neurite length, branching, and Sholl complexity in both sexes, with a more pronounced effect in males. A male-biased effect was also observed in synapse-related marker colocalization, with increased Syn1–Psd95 colocalization detected in males. Docking suggested plausible interactions of C3G and resveratrol with regulators such as MYC, TP53, and CREB1. Conclusions: CNP extract alters transcriptional networks and enhances neurite outgrowth in primary hippocampal neurons in a sex-dependent manner, with male-biased effects on Syn1–Psd95 colocalization. These findings support further dose–response, mechanistic, and sex-stratified in vivo studies to evaluate its neurobiological potential. Full article

Background/Objectives: Sex differences influence skin physiology, immune regulation, and disease susceptibility, but the cellular organization of sex-biased transcriptional programs in healthy human skin remains incompletely defined. We aimed to define sex-associated differences in cellular composition and gene expression in healthy adult truncal skin at single-cell resolution. Methods: We constructed a sex-resolved single-cell transcriptomic atlas of healthy human truncal skin by integrating scRNA-seq data from 12 donors (5 males, 7 females). After quality control, 107,967 cells were classified into 14 major cell types. Sex-associated differences were assessed using donor-level pseudo-bulk analyses at both whole-skin and cell-type-resolved levels. Results: The cellular composition was conserved between sexes, with significant differences in mast cells and regulatory T cells. Whole-skin pseudo-bulk analysis identified distinct male-biased and female-biased transcriptional programs. Male-biased signals were linked to extracellular matrix organization and immune responses, while female-biased signals involved ion transport and neuromodulation. Cell-type-resolved analysis revealed that most sex-biased genes were lineage-specific, with minimal cross-lineage sharing. Conclusions: Sexual dimorphism in healthy human truncal skin is encoded through lineage-structured transcriptional regulation rather than broad compositional changes, providing a framework for understanding sex-biased skin homeostasis and disease susceptibility. Full article

Sex determination in teleost fishes exhibits remarkable evolutionary plasticity; however, the underlying mechanisms remain largely elusive for many species of high economic importance. Herein, we provide the first genome-wide investigation of the genetic basis of sex determination in the European anchovy (Engraulis encrasicolus), an ecologically and commercially vital clupeiform fish. Using low-pass whole-genome resequencing of 100 sexually mature individuals (50 females and 50 males), we conducted a genome-wide association study (GWAS) and F_ST scans to identify sex-linked loci and characterize sex-determining regions (SDRs). Our analyses revealed two major candidate SDRs located on chromosomes 14 and 18, encompassing multiple sex-associated single-nucleotide polymorphisms (SNPs) and insertions/deletions (InDels). Among these, the amhr2 (anti-Müllerian hormone type 2 receptor) gene on Chr14 displayed the strongest and most consistent association with phenotypic sex, marked by several male-specific missense SNPs and InDel variants. Comparative and transcriptomic analyses confirmed sex-biased expression of amhr2 and other SDR-linked genes, potentially indicating a male heterogametic (XY-like) genetic sex determination system. These results provide the first molecular evidence for a candidate SDR in E. encrasicolus, raise the possibility of involvement of amhr2 and additional loci in sex determination, and highlight rapid sex chromosome turnover within Clupeiformes. Our findings not only expand the understanding of teleost sex determination evolution but also establish a genomic foundation for developing molecular tools for sex identification and population management in anchovy fisheries. Full article

The soybean pod borer, Leguminivora glycinivorella, is a monophagous pest that threatens soybean production. Its larvae feed concealed within pods, which limits the efficacy of conventional insecticides. Elucidating its chemosensory system is therefore essential for developing green, behavior-based management strategies. Reference-based transcriptomics across multiple tissues of L. glycinivorella identified a comprehensive repertoire of chemosensory genes, including 76 odorant receptors (ORs), 15 gustatory receptors (GRs), 18 ionotropic receptors (IRs), 52 odorant-binding proteins (OBPs), 18 chemosensory proteins (CSPs), and 4 sensory neuron membrane proteins (SNMPs). Sequence and phylogenetic analyses characterized these candidates within the context of known insect chemosensory families. Notably, canonical bitter GRs and specific IR lineages (e.g., IR100/IR85a) were not detected in our dataset, potentially reflecting adaptation to the specialized soybean-feeding habit of this pest. Expression profiling further revealed pronounced sexual and tissue dimorphism: male antennae showed significant enrichment of putative pheromone receptors (PRs) and LglySNMP1, whereas several OBPs and ORs exhibited female-biased expression, suggesting roles in host location and oviposition. Additionally, the high expression of GR43a homologs points to fructose sensing, while the lack of detectable CO₂ receptor components (except LglyGR2) suggests atypical carbon dioxide perception mechanisms. Collectively, this study provides a valuable expression atlas of chemosensory genes in L. glycinivorella and identifies sex-specific candidate genes for future functional validation and behavior-based pest management. Full article

Cheliped regeneration in the E. sinensis is a tightly regulated physiological process, yet the molecular regulatory mechanisms underlying sexual dimorphism during regeneration remain unclear. In this study, we combined morphological observation with transcriptomic analysis to systematically investigate the regenerative stage characteristics and sex-related differences. The papilla stage 4 dpa was identified as a pivotal transitional stage, bridging initial wound healing and cellular dedifferentiation (2 dpa) with subsequent redifferentiation and morphogenesis (7 dpa). Morphological sex-based differences characterized by larger regenerating chelipeds in males became prominent by the late stage (28 dpa). Notably, the molecular foundation of sexual dimorphism was found to be established at 4 dpa, significantly preceding the emergence of phenotypic differences. This early divergence was driven by sex-dimorphic endocrine networks: males exhibited preferential expression of genes such as Fem-1c-like, Cyp2L1-like, CpAMP1A-like and Nedd4-like, while females showed enrichment in elevated aromatase activity. Weighted gene co-expression network analysis (WGCNA) identified the Hox gene Antp as a core hub regulator, exhibiting high co-expression with key epidermal-related genes such as Cht6, Cht2-like and more. Its suppressed expression at 2 dpa aligned with the requirements for dedifferentiation, whereas its peak at 4 dpa indicated a crucial role in orchestrating appendage patterning and exoskeleton assembly. RNA interference (RNAi) knockdown of Antp resulted in obscured differentiation between the propodus and carpus in both sexes and confirmed its regulatory control over downstream targets including Ubx, Bmp2-like, and CpAMP1A-like. This study suggests a putative hierarchical regulatory model in which systemic hormonal signals may integrate Antp and other sex-biased regulators to potentially facilitate structured limb regeneration. These findings offer tentative novel insights into the interplay between developmental plasticity and sex-based regulatory divergence in decapod crustaceans. Full article

The freshwater snail Bellamya purificata is both ecologically and economically significant, exhibiting notable sexual dimorphism in growth and nutritional traits that underscore the importance of breeding of monosex stocks. However, the genetic basis of sex determination remains unclear. Herein, genome-wide association studies (GWASs) combined with transcriptomic analysis were conducted to identify sex-linked markers and candidate genes for this species. GWAS generated 571 significantly sex-associated SNPs and 1853 InDels, corresponding to 44 candidate genes. Multiple significant SNP peaks were detected on chromosomes 1 and 2, with mrc2 and mis18bp1 as key candidate genes. A sex-linked InDel marker located within mis18bp1 can distinguish males and females cost-effectively. Genotype analysis of the sex-associated loci revealed that most females were homozygous while males were heterozygous, suggesting that B. purificata has a primarily XX/XY sex determination system. Comparative gonadal transcriptome analyses identified 2996 female-biased and 4281 male-biased genes. Among them, sry, sox8, dmrt1 and dmrt2 may be critical in male sex differentiation, while β-catenin, foxl2, esr1 and nr5a2 may be important in female sex differentiation. Integration of GWAS and transcriptomic data highlighted four pronounced sex-associated candidate genes, including mis18bp1, rnf216, tbx1 and mrc2. These results provide a valuable foundation for elucidating the genetic mechanisms underlying sex determination and for the development of monosex stocks in B. purificata. Full article