Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, Guangxi 530021, China.
Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, Guangxi 530021, China; Key Laboratory of Aquatic Genetic Resources and Utilization, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China.
Comp Biochem Physiol B Biochem Mol Biol. 2019 Jun;232:93-100. doi: 10.1016/j.cbpb.2019.03.002. Epub 2019 Mar 18.
Hybrid Nile tilapia (Oreochromis niloticus, ♀) × blue tilapia (O. aureus, ♂) is a widely cultured tilapia variety due to its growth vigor compared to the parent species. As a peptide hormone, insulin-like growth factor 1 (IGF-1) plays a critical role in regulating somatic growth. The present study focuses on the expression characteristics of IGF-1 in hybrid tilapia. The cloned complete open reading frame of IGF-1 in hybrid tilapia is 549 bp in length, encoding a protein of 182 amino acids. The deduced protein is highly similar to that of Nile tilapia and blue tilapia. IGF-1 was found to be primarily expressed in the liver and muscle in the hybrid; lower expression levels were found in other tissues such as the intestine, spleen, and head-kidney. Increased mRNA expression was observed in the liver and muscle of the hybrid compared to Nile tilapia and blue tilapia, indicating a nonadditive expression pattern in the hybrid. An IGF-1 SNP site (397 site: C in Nile tilapia, G in blue tilapia) for differentiating the Nile tilapia or blue tilapia subgenome in hybrids was identified. Pyrosequencing analysis of the liver transcriptome indicated that most of the hybrids (9 of 10 individuals) predominantly expressed the G allele, demonstrating bias of the blue tilapia subgenome. The present study provides novel data indicating, for the first time, overall gene expression of IGF-1 and allele-specific expression in hybrid tilapia.
杂交尼罗罗非鱼（♀）×蓝罗非鱼（♂）是一种广泛养殖的罗非鱼品种，与亲本品系相比具有生长活力强的特点。胰岛素样生长因子 1（IGF-1）作为一种肽类激素，在调节体生长中发挥着重要作用。本研究主要关注杂交罗非鱼 IGF-1 的表达特征。克隆得到的杂交罗非鱼 IGF-1 完整开放阅读框长 549bp，编码 182 个氨基酸的蛋白质。推导的蛋白质与尼罗罗非鱼和蓝罗非鱼高度相似。IGF-1 在杂交鱼中主要在肝脏和肌肉中表达，在肠道、脾脏和头肾等其他组织中的表达水平较低。与尼罗罗非鱼和蓝罗非鱼相比，杂交鱼肝脏和肌肉中的 mRNA 表达水平增加，表明杂交鱼中存在非加性表达模式。鉴定出一个可区分杂交鱼中尼罗罗非鱼或蓝罗非鱼亚基因组的 IGF-1 SNP 位点（397 位：尼罗罗非鱼为 C，蓝罗非鱼为 G）。对肝脏转录组的焦磷酸测序分析表明，大多数杂交鱼（10 个个体中的 9 个）主要表达 G 等位基因，表明蓝罗非鱼亚基因组存在偏倚。本研究首次提供了杂交罗非鱼 IGF-1 总体基因表达和等位基因特异性表达的新数据。
