Bovine colostrum is essential for neonatal immunity and development, with its exosomal cargo of microRNAs (miRNA) playing a key role in intercellular communication. However, the specific immunomodulatory functions of these exosomes and their temporal variation remain unclear. This study aimed to isolate and characterize exosomes from bovine colostrum at 2 h (2h-Exo) and 24 h (24h-Exo) postpartum, evaluate their effects on cell proliferation and inflammation, and identify the underlying miRNA-mediated mechanisms. Exosomes were successfully isolated using an optimized method combining rennet enzyme digestion, filtration, and differential ultracentrifugation. Small RNA sequencing revealed 69 differentially expressed miRNAs between 2h-Exo and 24h-Exo (22 upregulated, 47 downregulated). Functionally, in an in vitro LPS-induced inflammatory model using macrophages, 2h-Exo demonstrated superior anti-inflammatory activity. It significantly reduced the expression of key proinflammatory cytokines, namely TNF-α, IL-1β, and IL-6, as well as IL-10, compared with 24h-Exo. Bioinformatic and functional analyses identified bta-miR-30a-5p as a critical, temporally enriched miRNA in 2h-Exo. Mechanistically, dual-luciferase reporter assays confirmed that bta-miR-30a-5p directly targets the 3'-untranslated region of the transcription factor SOX4. Furthermore, miR-30a-5p mimic transfection recapitulated the anti-inflammatory effect by downregulating SOX4 and attenuating the expression of TNF-α and IL-6. This study demonstrates that bovine colostrum exosomes, particularly those harvested immediately postpartum, possess potent immunomodulatory capacity. The anti-inflammatory effect is mediated, at least in part, by the exosomal delivery of bta-miR-30a-5p and its subsequent targeting of SOX4 mRNA. These findings highlight early colostrum as a valuable source of therapeutic exosomes and elucidate a specific miRNA-mRNA axis for regulating inflammation.

To assess the genetic diversity and matrilineal differentiation between the Betpak-Dala (BD) and Volga–Ural (VU) populations of Saiga tatarica in Kazakhstan, this study sequenced and comparatively analyzed the complete mitochondrial genomes of both populations. Phylogenetic analyses showed that Saiga tatarica clustered with the genera Gazella, Nanger, and Eudorcas, indicating a close evolutionary relationship. Genetic diversity analysis revealed that the BD population exhibited higher nucleotide diversity than the VU population. A total of 22 haplotypes were identified based on complete mitochondrial genome sequences, and no haplotypes were shared between the two populations, indicating pronounced matrilineal genetic differentiation. Synonymous mutations predominated among protein-coding genes, with the NADH dehydrogenase subunit 2 gene (nd2) and NADH dehydrogenase subunit 5 gene (nd5) genes exhibiting high levels of variation and serving as key regions for the accumulation of genetic diversity within the mitochondrial genome. These findings enhance the understanding of the genetic diversity and matrilineal genetic structure of Saiga tatarica populations in Kazakhstan and provide valuable information for their conservation and management.

Inhibin, a water-soluble protein emitted by the gonads, plays a pivotal role in regulating the release of follicle-stimulating hormone (FSH) from the pituitary gland, which, in turn, influences follicular growth, gamete production, and the secretion of associated hormones. We performed high-throughput sequencing of the nanobody gene in the lymphocytes of Bactrian camels before and after inhibin α protein immunization followed by mass spectrometry analysis of specific antibodies to this protein in the serum following immunization to screen for inhibin α subunit-specific nanobodies. Seven inhibin α-specific nanobodies, namely Nb-1712, Nb-1971, Nb-2000, Nb-799, Nb-2004, Nb-1737, and Nb-338, were identified through high-throughput sequencing and mass spectrometry. Following the construction and expression of a prokaryotic expression vector, five of these nanobody proteins were successfully produced. These proteins demonstrated high affinity for inhibin α in the indirect enzyme-linked immunosorbent assay. Notably, nanobodies Nb-1737, Nb-1971, and Nb-2004 significantly downregulated Inha and upregulated Fshb gene expression, enhancing follicle-stimulating hormone secretion. In female mice, these three nanobodies promoted follicular development and led to a numerical increase in litter size (average ~10%, with Nb-2004 showing a 14.93% increase), although the differences were not statistically significant. These findings demonstrate their potential to regulate reproductive function. We identified 7 inhibin α subunit-specific nanobody genes from a Xinjiang Bactrian camel’s lymphocyte genome through high-throughput sequencing and mass spectrometry. We also compared their relative binding affinities and characterized their biological functions, thereby providing key theoretical guidance and technical support for increasing FSH levels.