The gastrointestinal tract is essential for food digestion, nutrient absorption, waste elimination, and microbial defense. Single-cell transcriptome profiling of the intestinal tract has greatly enriched our understanding of cellular diversity, functional heterogeneity, and their importance in intestinal tract development and disease. Although such profiling has been extensively conducted in humans and mice, the single-cell gene expression landscape of the pig cecum remains unexplored. Here, single-cell RNA sequencing was performed on 45 572 cells obtained from seven cecal samples in pigs at four different developmental stages (days (D) 30, 42, 150, and 730). Analysis revealed 12 major cell types and 38 subtypes, as well as their distinctive genes, transcription factors, and regulons, many of which were conserved in humans. An increase in the relative proportions of CD8 + T and Granzyme A (low expression) natural killer T cells (GZMA low NKT) cells and a decrease in the relative proportions of epithelial stem cells, Tregs, RHEX + T cells, and plasmacytoid dendritic cells (pDCs) were noted across the developmental stages. Moreover, the post-weaning period exhibited an up-regulation in mitochondrial genes, COX2 and ND2, as well as genes involved in immune activation in multiple cell types. Cell-cell crosstalk analysis indicated that IBP6 + fibroblasts were the main signal senders at D30, whereas IBP6 - fibroblasts assumed this role at the other stages. NKT cells established interactions with epithelial cells and IBP6 + fibroblasts in the D730 cecum through mediation of GZMA-F2RL1/F2RL2 pairs. This study provides valuable insights into cellular heterogeneity and function in the pig cecum at different development stages.
肠道在消化食物、吸收营养、排出粪便和抵御微生物方面起着至关重要的作用。单细胞转录组的研究对理解肠道发育和疾病的细胞及基因表达基础具有重要意义。尽管肠道的单细胞转录组在人类和小鼠中已经被广泛研究，猪不同发育阶段盲肠单细胞基因表达谱仍未被报道。该研究首次对出生后30（断奶前）、42（断奶后）、150和730天的四个发育阶段巴马香猪的7个猪盲肠样本进行了单细胞转录组测序，鉴定到了45 572个细胞，涉及12种主要的细胞类型和38种细胞亚型。通过差异表达分析，进一步鉴定了这些细胞类型的特征基因和转录因子，并发现其中许多细胞类型特异表达基因在人类中是保守的。我们发现，随年龄增长，CD8 + T、GZMA low NKT的相对比例逐渐增加，而上皮干细胞、调节性T细胞（Tregs）、RHEX + T细胞和pDCs相对比例逐渐减少。相比断奶前，断奶后线粒体基因COX2和ND2，以及涉及免疫激活的基因在多种细胞类型中上调。细胞间通讯分析进一步发现随发育阶段动态变化的细胞-细胞互作，例如，IBP6 +成纤维细胞在D30阶段充当主要的信号发送者，而在其它阶段，IBP6 -成纤维细胞接管了这个角色。NTK细胞仅在D730阶段盲肠中通过GZMA配体与上皮细胞和IBP6 +成纤维细胞上的F2RL1/F2RL2受体相互作用。该研究结果为猪盲肠不同发育阶段，包括断奶前后的细胞类型异质性和功能相关研究提供了宝贵数据和重要见解。.
Keywords: Bama Xiang pigs; Cecum; Cellular heterogeneity; Single-cell RNA-seq; Various developmental stages.