Circular RNAs (circRNAs) have been identified as a novel type of regulators involved in multiple biological processes. However, circRNAs with a potential function in fat deposition in buffalo are poorly understood. In this study, six RNA libraries of adipose tissue were constructed for three young and three adult Chinese buffaloes with paired-ends RNA sequencing using the Illumina HiSeq 3000 platform. A total of 5141 circRNAs were computationally identified. Among them, 252 circRNAs were differentially expressed (DE) between the young and adult buffaloes. Of these, 54 were upregulated and 198 were downregulated in the adult group. Eight DE circRNAs were further identified by quantitative real-time-PCR (qRT-PCR) and Sanger sequencing. Co-expression analysis revealed that 34 circRNAs demonstrated a strong correlation with fat deposition-associated genes (|r| > 0.980). Among these, expressional correlation between two circRNAs (19:45387150|45389986 and 21:6969877|69753491) and PR/SET domain 16 was further verified using qRT-PCR, and a strong correlation was revealed (1 > |r| > 0.8). These results strongly suggest that circRNAs 19:45387150|45389986 and 21:6969877|69753491 are potential regulators of buffalo fat deposition. In summary, this study characterized the circRNA profiles of adipose tissues at different stages for the first time and revealed two circRNAs strongly correlated with fat deposition-associated genes, which provided new candidate regulators for fat deposition in buffalo.

Hypoxia benefits the proliferation and maintenance of animal spermatogonial cells; however, the underlying mechanism remains incompletely understood. This study aims to investigate the role and mechanism of the hypoxia–glycolysis–histone lactylation axis in the proliferation of buffalo spermatogonial cells (bSCs). bSCs were cultured under different oxygen concentrations to observe changes in cell proliferation. RNA-seq was used to analyze gene expression and signaling pathways. Changes in lactylation were monitored, and CUT&Tag-seq was utilized to determine the regulatory effects of lactylation on gene expression. The glycolytic pathway was regulated to validate the results of the bioinformatic analysis. Oxygen concentrations between 2.5% and 10% support the proliferation of bSCs, with 5% having the most pronounced effect. An amount of 5% oxygen significantly increased the proliferation and pluripotency of bSCs while also promoting glycolysis and lactylation. Inhibition of glycolysis eliminated the proliferative effects of hypoxia. By analyzing genes associated with the key lactylation site H3K18la using CUT&Tag technology, we found that it is closely linked to genes involved in the regulation of proliferation. After inhibition of HK-2 expression, cell proliferation, H3K18la expression, and the expression of these target genes were all suppressed. Hypoxia promotes the proliferation of bSCs via activation of glycolysis, leading to an increase in H3K18la and altered expression of its target genes.

Identification of selection signature is important for a better understanding of genetic mechanisms that affect phenotypic differentiation in livestock. However, the genome-wide selection responses have not been investigated for the production traits of Chinese crossbred buffaloes. In this study, an SNP data set of 133 buffaloes (Chinese crossbred buffalo, n = 45; Chinese local swamp buffalo, n = 88) was collected from the Dryad Digital Repository database (https://datadryad.org/stash/). Population genetics analysis showed that these buffaloes were divided into the following 2 groups: crossbred buffalo and swamp buffalo. The crossbred group had higher genetic diversity than the swamp group. Using 3 complementary statistical methods (integrated haplotype score, cross population extended haplotype homozygosity, and composite likelihood ratio), a total of 31 candidate selection regions were identified in the Chinese crossbred population. Here, within these candidate regions, 25 genes were under the putative selection. Among them, several candidate genes were reported to be associated with production traits. In addition, we identified 13 selection regions that overlapped with bovine QTLs that were mainly involved in milk production and composition traits. These results can provide useful insights regarding the selection response for production traits of Chinese crossbred buffalo, as identified candidate genes influence production performance.

Curcumin (Cur) is a flavonoid derived from Curcuma longa L. that has been shown to have a variety of biological activities, but some previous studies have described its non-negligible negative effects on female reproduction and embryo development. To further explore the toxic stress effect, this study investigated apoptosis and autophagy of healthy buffalo (Bubalus bubalis) derived granulosa cells (GCs) exposed to Cur and/or autophagy inhibitors. Results showed that Cur declined viability of GCs in a concentration-dependent manner. Apoptosis was observed in Cur-treated GCs from 3 h. Meanwhile, under Cur stress, autophagosomes accumulated in cells, and the expression levels of autophagy key proteins LC3 and Beclin 1 were up-regulated, suggesting that Cur could induce autophagy in GCs. Early autophagy inhibitor 3-methyladenine (3-MA) increased the apoptosis rate of Cur exposed GCs, but the autophagosome degradation inhibitor chloroquine (CQ) had no effect on the apoptosis rate. The network pharmacological and molecular docking analysis indicated that the perturbation of IKK/NF-κB might be the cause of Cur toxicity toward GCs. This study unveiled another side of Cur pharmacological effects that programmed cell death can be induced by Cur in GCs, suggesting that it should be prudent to use Cur as a clinical drug for its side effects on the female reproductive system.