Abstract Background The ovary is a central female reproductive organ responsible for producing oocytes and secreting steroid hormones. To investigate the molecular similarities and potential evolutionary origins of the ovary across vertebrates, we integrated publicly available single-cell and single-nucleus transcriptomic data from nine species, including oviparous animals (fish and chicken) and viviparous mammals (mouse, rat, sheep, goat, yak, monkey, and human). Results We generated a multi-species ovarian atlas comprising 186,748 cells and identified nine cell types. Cross-species comparative analysis identified conserved and species-specific features in granulosa cells (GCs) and stromal cells (SCs), including gene expression patterns, signaling pathways, and cell–cell communication networks. For example, proliferation-associated genes such as CKAP5, MCM3, and GINS1 were shared across vertebrates in GC-3, highlighting the evolutionary conservation of the molecular machinery underlying granulosa cell division. A comparison of granulosa cell subtypes further revealed species-specific gene co-expression patterns in oviparous and viviparous species, indicating adaptations for their different reproductive strategies. Stromal cells showed strong evolutionary conservation, as core extracellular matrix genes (e.g., COL6A1, FSTL1, ACTN1) were co-expressed across species in SC-1. Moreover, the conserved ligand-receptor pairs such as COL4A1-CD44, COL1A1-SDC4, LAMB1-ITGA6-ITGB1, and VEGFA-NRP2 constituted fundamental signaling axes of follicle development, while interactions such as PPIA-BSG in mouse and MDK-NCL in human were higher in these species compared with others, reflecting species-specific ovarian cell communication during evolution. Conclusions These findings provide comprehensive insights into the molecular evolution and cellular diversity of the ovary, offering a valuable resource for understanding ovarian biology and evolutionary mechanisms.
Methane emissions from livestock are a significant contributor to agricultural greenhouse gas outputs, yet region-specific emission factors are often lacking for nomadic pastoral systems. This study determined annual enteric methane emission factors for sheep across three major agro-ecological zones of Mongolia: Desert-steppe, steppe, and forest-steppe, considering animal sex and age categories. Animal performance data were collected for adult males (>3 years), adult females (>3 years), young sheep (1-2 years), and lambs (<1 year). According to the IPCC Tier 1 methodology, the default emission factor for adult sheep is 5 kg CH4/head/year, while lamb values are estimated at approximately 2 kg CH4/head/year. Nevertheless, these generalized values fail to capture country-specific differences in animal productivity, diet quality, seasonal feed availability, and grazing management, thereby introducing significant uncertainty into national greenhouse gas inventories. Results showed that females consistently exhibited higher emission factors than males, with values ranging from 6.0 to 6.1 kg CH4/head/year, compared to 5.40-5.45 kg CH4/head/year for males. Young sheep emitted between 4.3 and 4.9 kg CH4/head/year, while lamb emissions were lowest at 1.6-1.8 kg CH4/head/year. These findings provide updated, region-specific methane emission factors for Mongolian sheep, supporting the refinement of national greenhouse gas inventories and climate change mitigation strategies.
Yak diarrhea is a major health concern in high-altitude regions, yet data are lacking in Ganzi Tibetan Autonomous Prefecture, a key yak-producing area in China. This study aimed to describe the prevalence, mortality, seasonal patterns, and pathogen profiles of yak diarrhea in Ganzi Prefecture. Between 2017 and 2024, surveys were conducted across 5 counties, involving 5 cooperatives and 62 households. Fecal and blood samples were collected from healthy (n = 1805) and diarrheic yaks (n = 189) for pathogen detection. Among 1.9066 million yaks, breeding females accounted for 48.48% and calves 26.32%. Diarrhea prevalence was 12.22% in adult yaks and 20.91% in calves, with mortality rates of 15.71% and 28.29%, respectively. Cases peaked in spring and winter. Pathogen detection in healthy yaks revealed intestinal parasites (43.26%) and BVDV (2.33%). In diarrheic yaks, higher rates were observed for intestinal parasites (46.56%), E. coli (10.05%), Salmonella (10.58%), BVDV (22.75%), and Theileria (25.40%). Mixed infections were common. These findings provide a descriptive baseline for guiding region-specific control strategies.
This study was conducted to determine whether air velocity applied during the brooding period exerts carryover effects on subsequent growth performance, body size traits, serum biochemical variables, and intestinal digestive enzyme activities of Pekin ducks at 42 d of age. A total of 90 healthy 7-d-old male ducks with similar initial body weight were randomly assigned to 3 air velocity treatments (0, 0.5, and 1.0 m/s), with 3 replicates per treatment and 10 ducks per replicate. Air velocity treatments were applied from 11 to 21 d of age, after which all ducks were reared under the same conventional conditions until 42 d. Feed intake and body weight were recorded throughout the experiment, body size traits, slaughter traits, serum biochemical variables, and intestinal digestive enzyme activities were determined at 42 d of age. As a result, air velocity significantly affected BW, ADG, ADFI, and FCR at 42 d of age (P=0.001 for each variable). Ducks exposed to 1.0 m/s during brooding had the highest BW, ADG, and ADFI and the lowest FCR among the three treatments. Oblique body length, keel length, chest depth, chest width, and hip width were also greater in the 1.0 m/s group, whereas several other body size traits were unaffected. Breast muscle yield (P=0.260) and leg muscle yield (P=0.088) were not affected by treatment, whereas abdominal fat weight (P=0.024) and abdominal fat yield (P= 0.020) were higher in the 1.0 m/s group. Among the serum biochemical variables, only UA differed among treatments (P=0.0013), whereas GLU, TP, LDH, AST, ALT, LDL-C, HDL-C, TG, and CHOL were unaffected. Activities of lipase, trypsin, amylase, sucrase, maltase, and alkaline phosphatase were generally higher in ducks exposed to 1.0 m/s during brooding, with significant treatment effects observed in the duodenum, jejunum, and ileum, whereas no significant differences were detected in the cecum. These findings indicate that air velocity applied from 11 to 21 d of age can exert carryover effects on subsequent growth, body development, carcass fat deposition, and luminal digestive enzyme activity in Pekin ducks.
