College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450046, China.
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450046, China; Henan Key Laboratory for Innovation and Utilization of Chicken Germplasm Resources, Zhengzhou 450046, China; International Joint Research Laboratory for Poultry Breeding of Henan, Zhengzhou 450046, China.
Poult Sci. 2023 Mar;102(3):102411. doi: 10.1016/j.psj.2022.102411. Epub 2022 Dec 9.
The insulin-like growth factor (IGF) system plays an indispensable role in embryonic and postnatal development in mammals. However, the effects of the system on growth, carcass, and egg-laying traits, and diversified selection have not been systematically studied in chickens. In the present study, firstly the composition and gene structures of the chicken IGF system were investigated using phylogenetic tree and conserved synteny analysis. Then the effects of the genetic variations in the IGF system genes on breeding of specialized varieties were explored by principal component analysis. In addition, the spatiotemporal expression properties of the genes in this system were analyzed by RT-qPCR and the functions of the genes in egg production performance and growth were explored by association study. Moreover, the effects of IGF-binding proteins 3 (IGFBP3) on skeletal muscle development in chicken were investigated by cell cycle analysis, 5-ethynyl-2'-deoxyuridine (EdU) and Cell Counting Kit-8 (CCK-8) assays. The results showed that the chicken IGF system included 13 members which could be classified into 3 groups based on their amino acid sequences: IGF binding proteins 1 to 5 and 7 (IGFBP1-5 and 7) belonged to the first group; IGF 1 and 2 (IGF1 and IGF2), and IGF 1 and 2 receptor (IGF1R and IGF2R) belonged to the second group; and IGF2 binding proteins 1-3 (IGF2BP1-3) belonged to the third group. The IGF2BP1 and 3, and IGFBP2, 3, and 7 genes likely contributed more to the formation of both the specialized meat-type and egg-type lines, whereas IGFBP1 and 5 likely contributed more to the formation of the egg-type lines. The SNPs in the IGF2BP3 and IGFBP2 and 5 genes were significantly associated with egg number, and SNPs in the IGFBP3 promoter region were significantly associated with body weight, breast muscle weight and leg muscle weight. The IGFBP3 inhibited proliferation but promoted differentiation of chicken primary myoblasts (CPMs). These results provide insights into the roles of the IGF system in the diversified selection of chickens. The SNPs associated with egg-laying performance, growth, and carcass traits could be used as genetic markers for breeding selection of chickens in the future.
胰岛素样生长因子（IGF）系统在哺乳动物的胚胎和出生后发育中起着不可或缺的作用。然而，该系统对生长、胴体和产卵性状以及多样化选择的影响尚未在鸡中进行系统研究。在本研究中，首先使用系统发生树和保守同线性分析研究了鸡 IGF 系统的组成和基因结构。然后，通过主成分分析探索了 IGF 系统基因的遗传变异对专门品种培育的影响。此外，通过 RT-qPCR 分析了该系统中基因的时空表达特性，并通过关联研究探索了基因在产蛋性能和生长中的功能。此外，通过细胞周期分析、5-乙炔基-2'-脱氧尿苷（EdU）和细胞计数试剂盒-8（CCK-8）检测研究了 IGF 结合蛋白 3（IGFBP3）对鸡骨骼肌发育的影响。结果表明，鸡 IGF 系统包括 13 个成员，根据其氨基酸序列可分为 3 组：IGF 结合蛋白 1-5 和 7（IGFBP1-5 和 7）属于第一组；IGF1 和 2（IGF1 和 IGF2）和 IGF1 和 2 受体（IGF1R 和 IGF2R）属于第二组；IGF2 结合蛋白 1-3（IGF2BP1-3）属于第三组。IGF2BP1 和 3 以及 IGFBP2、3 和 7 基因可能对专门的肉型和蛋型鸡的形成贡献更大，而 IGFBP1 和 5 基因可能对蛋型鸡的形成贡献更大。IGF2BP3 和 IGFBP2 和 5 基因中的 SNPs 与产蛋数显著相关，IGFBP3 启动子区域的 SNPs 与体重、胸肌重和腿肌重显著相关。IGFBP3 抑制鸡原代成肌细胞（CPMs）的增殖但促进其分化。这些结果为 IGF 系统在鸡的多样化选择中的作用提供了新的认识。与产蛋性能、生长和胴体性状相关的 SNPs 可作为未来鸡种选育的遗传标记。
