目前尚不清楚驱动鸟脚上羽毛和鳞片多样化分布和形态发生的遗传和发育因素。在一个物种中,广西家鸡在羽毛脚上表现出戏剧性的变化,使它们成为研究皮肤附属物变化的分子基础的可访问模型。在这项研究中,我们用H&E染色观察羽毛足的形态发生,龙胜凤鸡和广西Partridge鸡在不同胚胎阶段的双足和翅膀皮肤。我们选择了在羽毛发育中起重要作用的4个时期(E6,E7,E8和E12),并进行了转录组测序以筛选与羽毛脚相关的候选基因。通过对转录组数据的比较和分析,我们确定了一组不同表达的基因(DGE),富含附肢器官发育,后肢形态发生,转录因子结合的激活,和序列特异性DNA在顺式调节区中的结合。此外,通过分析调节羽毛发育的经典信号通路,我们发现了一些与羽毛相关的基因.最后,我们确定了调节羽毛脚形成的候选基因,其中包括TBX5,PITX1,ZIC1,FGF20,WNT11,WNT7A,WNT16和SHH.有趣的是,我们发现TBX5在羽毛足的皮肤中明显过表达,在E7处表达最高(P<0.01),而PITX1在E7时表达显著降低(P<0.01)。假设TBX5和PITX1在E7通过Wnt/β-连环蛋白信号通路调节毛囊的发育。我们的研究结果为研究鸡羽毛足形成的分子调控机制提供了理论依据。
The genetic and developmental factors driving the diverse distribution and morphogenesis of feathers and scales on bird feet are yet unclear. Within a single species, Guangxi domestic chickens exhibit dramatic variety in feathered feet, making them an accessible model for research into the molecular basis of variations in skin appendages. In this study, we used H&E staining to observe the morphogenesis of feathered feet, scaled feet and wings skin at different embryonic stages in Longsheng-Feng chickens and Guangxi Partridge chickens. We selected 4 periods (E6, E7, E8, and E12) that play an important role in feather development and performed transcriptome sequencing to screen for candidate genes associated with feathered feet. Through comparison and analysis of transcriptome data, we identified a set of differently expressed genes (DGEs), which were enriched in appendage organ development, hindlimb morphogenesis, activation of transcription factor binding, and binding of sequence-specific DNA in the cis-regulatory region. In addition, we identified some feathered feet-related genes by analyzing the classical signaling pathways that regulate feather development. Finally, we identified candidate genes that regulate feathered feet formation, which include
TBX5, PITX1, ZIC1, FGF20, WNT11, WNT7A, WNT16, and SHH. Interestingly, we found that
TBX5 was significantly overexpressed in the skin of the feathered feet and had the highest expression at E7 (P < 0.01), whereas PITX1 expression was significantly reduced at E7(P < 0.01). It is hypothesized that
TBX5 and PITX1 regulate the development of hair follicles through the Wnt/β-catenin signaling pathway at E7. Our results provide a theoretical basis for investigating the molecular regulatory mechanisms underlying the formation of chicken feathered feet.