Cdc42基因对不同发育阶段无尾鸡骨骼的共表达调控

Co-expression Regulation of Cdc42 Gene in the Bone of Rumpless Chickens at Different Developmental Stages

为阐明细胞分裂周期42(cell division cycle 42,Cdc42)基因在无尾鸡骨骼发育过程的潜在调控机制,本试验通过混池重测序与转录组测序方法,综合运用基因组学和骨骼转录组学来揭示Cdc42基因对无尾鸡尾部发育的遗传影响。结果显示,在无尾品种的强正向选择下,无尾鸡与有尾鸡之间高度分化的基因显著富集到神经发育、基础代谢与细胞骨架重排等生物类别;骨骼发育过程的差异表达基因数从胚胎第8、11和14天逐渐升高后下降,到第16天到达最低后又升高,到第21天达到最高;在基因组与转录组层面识别的公共候选基因为Cdc42;公共生物学过程富集到GTPases活性与细胞生长程度的调节,公共信号通路富集到紧密连接与黏着连接;差异表达基因构建的权重基因共表达网络发现,无尾鸡比有尾鸡的基因网络密度高6倍以上,平均连接度高8倍以上。无尾鸡共表达网络中,Cdc42基因与其他基因的相关性较弱。相比而言,在有尾鸡组,Cdc42基因处于网络的核心连接节点处,对于多基因的共同调节起到桥梁作用;此外,证明了Cdc42基因在多物种间具有保守性。本研究最终确定瓢鸡无尾性状的形成可能通过Cdc42及其共表达的基因共同调控紧密连接信号通路,联动影响Wnt信号通路,进而干扰生长板和尾骨的发育,是尾骨提前终止的重要影响环节,将为瓢鸡无尾表型的早期启动和遗传基础认识提供理论指导。

To elucidate the potential regulatory mechanism of cell division cycle 42(Cdc42)gene in the skeletal development of rumpless chicken,in this study,the hereditation of Cdc42 gene on tail development of rumpless chicken was revealed by genome pool resequencing and RNA sequencing,combined with genomics and bone development transcriptomics.Under the strong positive selection of the rumpless varieties,highly differentiated genes were significantly enriched in biological process such as neural development,basal metabolism and cytoskeleton rearrangement between rumpless and tailed chickens.The number of differentially expressed genes during bone development increased gradually next to decreased from the 8th,11th and 14th day of embryo,on the 16th day it reached the lowest level and then rose again and reached the peak on the 21st day of embryo.The common candidate Cdc42 gene was identified at the genomics and transcriptomics levels.The common biological processes enriched in regulation of GTPase activity and the regulation of extent of cell growth.Common signaling pathways include tight junctions and adherens junctions.The weighted gene co-expression network analysis by differentially expressed genes showed that the density of gene network was more than 6 times higher and the average connectivity was more than 8 times higher in rumpless chicken than that of tailed chicken.The correlation between Cdc42 gene and other genes was low in the co-expression network of rumpless chicken.In contrast,Cdc42 gene was at the core of the network and acted as a bridge for the co-regulation of multiple genes in tailed chicken.In addition,Cdc42 gene was proved to be conserved among multiple species.In this study,it was finally determined that the formation of the rumpless trait in Piao chicken might co-regulate the tight junction signaling pathway through Cdc42 and its co-expressed genes,and interact with the Wnt signaling pathway,thus interfering with the development of growth plate and coccyx,and ultimately affecting the important link of premature termination of coccyx.These results would be provided theoretical guidance for the early initiation and genetic basis of rumpless phenotype.