The mechanism of bovine endometrial regeneration after parturition remains unclear. Here, we hypothesized that bovine endometrial stem/progenitor cells participate in the postpartum regeneration of the endometrium. Flow cytometry analysis identified the presence of side population (SP) cells among endometrial stromal cells. Endometrial SP cells were shown to differentiate into osteoblasts and adipocytes. RNA-seq data showed that the gene expression pattern was different between bovine endometrial SP cells and main population cells. Gene Set Enrichment Analysis identified the enrichment of stemness genes in SP cells. Significantly (false discovery rate < 0.01) upregulated genes in SP cells contained several stem cell marker genes. Gene ontology (GO) analysis of the upregulated genes in SP cells showed enrichment of terms related to RNA metabolic process and transcription. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of upregulated genes in SP cells revealed enrichment of signaling pathways associated with maintenance and differentiation of stem/progenitor cells. The terms involved in TCA cycles were enriched in GO and KEGG pathway analysis of downregulated genes in SP cells. These results support the assumption that bovine endometrial SP cells exhibit characteristics of somatic stem/progenitor cells. The ratio of SP cells to endometrial cells was lowest on days 9–11 after parturition, which gradually increased thereafter. SP cells were shown to differentiate into epithelial cells. Collectively, these results suggest that bovine endometrial SP cells were temporarily reduced immediately after calving possibly due to their differentiation to provide new endometrial cells.

中文翻译：

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牛子宫内膜侧群细胞的基因表达谱和产后转变†

产后牛子宫内膜再生的机制尚不清楚。在这里，我们假设牛子宫内膜干/祖细胞参与了子宫内膜的产后再生。流式细胞术分析确定了子宫内膜基质细胞中存在侧群 (SP) 细胞。显示子宫内膜 SP 细胞分化为成骨细胞和脂肪细胞。RNA-seq 数据显示，牛子宫内膜 SP 细胞和主要群体细胞之间的基因表达模式不同。基因集富集分析确定了 SP 细胞中干性基因的富集。SP 细胞中显着上调的基因（错误发现率＜0.01）含有几个干细胞标记基因。SP 细胞中上调基因的基因本体论 (GO) 分析显示与 RNA 代谢过程和转录相关的术语的富集。京都基因和基因组百科全书 (KEGG) 对 SP 细胞中上调基因的通路分析揭示了与干/祖细胞维持和分化相关的信号通路的富集。TCA 循环中涉及的术语在 SP 细胞中下调基因的 GO 和 KEGG 通路分析中得到了丰富。这些结果支持牛子宫内膜 SP 细胞表现出体干/祖细胞特征的假设。SP细胞与子宫内膜细胞的比例在分娩后第9-11天最低，此后逐渐增加。SP 细胞显示分化为上皮细胞。集体，