The Tibetan chicken (Gallus gallus) provides high quality protein and iron for humans, which shows many phenotypic adaptations to the low oxygen. Study of the genetic mechanisms of circular RNAs (circRNAs) in hypoxia adaptation has not been reported. Four embryonic heart tissue samples from Tibetan chickens and Daheng broilers were collected. Differentially expressed circRNAs (DEcircRNAs) were identified via high-throughput sequencing. Bioinformatic analysis was used to indicate the functions and pathways of the DEcircRNAs. A total of 29 DEcircRNAs were identified between 4 Tibetan chickens and 4 Daheng broilers, including 15 upregulated and 14 downregulated DEcircRNAs in Tibetan chickens. GO analysis revealed that the DEcircRNAs were mainly involved in lung development or oxygen metabolism, such as ubiqunegative regulation of mesenchymal cell proliferation involved in lung development, oxidoreductase activity, and peroxisome. Pathway analysis showed that DEcircRNAs were mainly enriched in oxidative phosphorylation, tight junction, VEGF/MAPK/PPAR/Ras/PI3K-Akt signaling pathway. We also constructed a circRNA-miRNA-mRNA-pathway network to visualize the regulatory relationship associated with hypoxia adaptation of the tight junction pathways. The circRNA expression profile was obtained to complement the current Tibetan chicken circRNA database and provides new information for future studies into biological adaptation to hypoxic stress in the Tibetan chicken.

藏鸡（Gallus gallus) 为人类提供高质量的蛋白质和铁，这显示出许多对低氧的表型适应。关于circRNAs（circRNAs）在缺氧适应中的遗传机制的研究尚未见报道。收集了来自藏鸡和大恒肉鸡的四个胚胎心脏组织样本。通过高通量测序鉴定差异表达的circRNA（DEcircRNA）。生物信息学分析用于指示 DEcircRNA 的功能和途径。在4只藏鸡和4只大恒肉鸡之间共鉴定出29个DEcircRNAs，其中在藏鸡中15个上调和14个下调的DEcircRNAs。GO分析显示DEcircRNAs主要参与肺发育或氧代谢，例如涉及肺发育、氧化还原酶活性和过氧化物酶体的间充质细胞增殖的泛素负调节。通路分析表明，DEcircRNAs主要富集于氧化磷酸化、紧密连接、VEGF/MAPK/PPAR/Ras/PI3K-Akt信号通路。我们还构建了一个 circRNA-miRNA-mRNA 通路网络来可视化与紧密连接通路的缺氧适应相关的调节关系。获得的 circRNA 表达谱是对当前藏鸡 circRNA 数据库的补充，并为未来研究藏鸡对缺氧胁迫的生物适应提供了新的信息。VEGF/MAPK/PPAR/Ras/PI3K-Akt 信号通路。我们还构建了一个 circRNA-miRNA-mRNA 通路网络来可视化与紧密连接通路的缺氧适应相关的调节关系。获得的 circRNA 表达谱是对当前藏鸡 circRNA 数据库的补充，并为未来研究藏鸡对缺氧胁迫的生物适应提供了新的信息。VEGF/MAPK/PPAR/Ras/PI3K-Akt 信号通路。我们还构建了一个 circRNA-miRNA-mRNA 通路网络来可视化与紧密连接通路的缺氧适应相关的调节关系。获得的 circRNA 表达谱是对当前藏鸡 circRNA 数据库的补充，并为未来研究藏鸡对缺氧胁迫的生物适应提供了新的信息。