Selenium (Se), a component of selenoproteins and selenocompounds in the human body, is crucial for the development of male reproductive organs, DNA synthesis, thyroid hormone, metabolism, and defence against infections and oxidative damage. In the testis, it must exceed a desirable level since either a shortage or an overabundance causes aberrant growth. The antioxidant properties of selenium are essential for preserving human reproductive health. Selenoproteins, which have important structural and enzymatic properties, control the biological activities of Se primarily. These proteins specifically have a role in metabolism and a variety of cellular processes, such as the control of selenium transport, thyroid hormone metabolism, immunity, and redox balance. Selenium nanoparticles (SeNPs) are less hazardous than selenium-based inorganic and organic materials. Upon being functionalized with active targeting ligands, they are both biocompatible and capable of efficiently delivering combinations of payloads to particular cells. In this review, we discuss briefly the chemistry, structure and functions of selenium and milestones of selenium and selenoproteins. Next we discuss the various factors influences male infertility, biological functions of selenium and selenoproteins, and role of selenium and selenoproteins in spermatogenesis and male fertility. Furthermore, we discuss the molecular mechanism of selenium transport and protective effects of selenium on oxidative stress, apoptosis and inflammation. We also highlight critical contribution of selenium nanoparticles on male fertility and spermatogenesis. Finally ends with conclusion and future perspectives.

Background: Cattle (Bos taurus) are a major large livestock, however, compared with other species, the transcriptional specificity of bovine oocyte development has not been emphasised.Results: To reveal the unique transcriptional signatures of bovine oocyte development, we used integrated multispecies comparative analysis and weighted gene co-expression network analysis (WGCNA) to perform bioinformatic analysis of the germinal follicle (GV) and second meiosis (MII) gene expression profile from cattle, sheep, pigs and mice. We found that the expression levels of most genes were down-regulated from GV to MII in all species. Next, the multispecies comparative analysis showed more genes involved in the regulation of cAMP signalling during bovine oocyte development. Moreover, the green module identified by WGCNA was closely related to bovine oocyte development. Finally, integrated multispecies comparative analysis and WGCNA picked up 61 bovine-specific signature genes that participate in metabolic regulation and steroid hormone biosynthesis.Conclusion: In a short, this study provides new insights into the regulation of cattle oocyte development from a cross-species comparison.

Egg quality is a critical economic trait in poultry production, influencing consumer preference and production efficiency. The genetic and epigenetic regulation of egg quality involves complex biological pathways across various traits such as shell quality, albumen composition, and yolk biochemistry. This review synthesizes recent advances in the genetic, molecular, and epigenetic mechanisms that determine poultry egg quality. Specifically, it focuses on external traits such as eggshell strength, color, and thickness, and internal traits including albumen height, yolk composition, and the Haugh unit. Through genome-wide association studies (GWAS), quantitative trait loci (QTL) mapping, whole-genome sequencing (WGS), and multi-omics approaches, key candidate genes such as OC-116, CALB1, CA2 (shell formation), OVAL, SPINK5, SERPINB14 (albumen quality), and FGF9, PIAS1, NOX5 (lipid metabolism) have been identified. These genes play a pivotal role in shell biomineralization, albumen protein regulation, and yolk lipid transport. This review also explores the heritability of these traits, emphasizing the challenges posed by polygenic architecture and the influence of environmental factors. Furthermore, it addresses the dynamic spatiotemporal regulation of egg quality traits, including epigenetic layers such as DNA methylation, histone modifications, RNA methylation, and post-translational protein modifications. This paper highlights the application of these findings to breeding programs via genomic selection, marker-assisted breeding, and epigenetic engineering approaches. Future directions for precision breeding and the development of functional eggs with enhanced quality are also discussed.

The content of intramuscular fat (IMF) from preadipocytes is proportional to meat quality in livestock. However, the roles of circRNAs in IMF deposition in sheep are not well known. In this study, we show that circRNA-5335/miR-125a-3p/STAT3 play a crucial adjective role in the proliferation and differentiation of sheep preadipocytes. In this study, we characterized the roles of differentially expressed circRNA-5335/miR-125a-3p/STAT3, which were screened from sheep of different months of age and based on sequencing data. Firstly, the expression profiles of circRNA-5335/miR-125a-3p/STAT3 were identified during the differentiation of preadipocytes in vitro by RT-qPCR and WB. Then, the targeting relationship of the circRNA-5335/miR-125a-3p/STAT3 was verified by dual-luciferase reporter assays. The results of RT-qPCR, CCK8, EdU and Oil Red O staining assay showed that miR-125a-3p suppressed the differentiation and raised the proliferation of preadipocytes by targeting STAT3. As a competing endogenous RNA, the downregulation of circRNA-5335 decreased the expression of STAT3 by increasing miR-125a-3p, which inhibited the differentiation of preadipocytes and promoted proliferation. Our present study demonstrates the functional significance of circRNA-5335/miR-125a-3p/STAT3 in the differentiation of sheep preadipocytes, and provides novel insights into exploring the mechanism of IMF.

Twinning trait in donkeys is an important manifestation of high fecundity, but few reports are available elucidating its genetic mechanism. To explore the genetic mechanism underlying the twin colt trait in Dezhou donkeys, DNA from 21 female Dezhou donkeys that had birthed single or twin colts were collected for whole-genome resequencing. F_ST, θπ and Tajima’s D were used to detect the selective sweeps between single and twin colt fecundity in the Dezhou donkey groups. Another set of 20 female Dezhou donkeys with single or multiple follicles during estrus were selected to compare concentrations of reproductive hormone including follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E₂) and progesterone (P₄). Four candidate genes including ENO2, PTPN11, SOD2 and CD44 were identified in the present study. The CD44 gene had the highest F_ST value, and ENO2, PTPN11 and SOD2 were screened by two joint analyses (F_ST and θπ, θπ and Tajima’s D). There was no significant difference in the LH, FSH and P₄ levels between the two groups (p > 0.05); however, the serum E₂ content in the multi-follicle group was significantly higher than that in the single-follicle group (p < 0.05). The identified candidate genes may provide new insights into the genetic mechanism of donkey prolificacy and may be useful targets for further research on high reproductive efficiency.