太行鸡FST基因克隆、序列特征及表达分析

旨在基于生物信息学方法分析太行鸡卵泡抑素基因（follistatin，FST），并研究其在不同组织及卵泡不同发育时期表达差异，解析FST对太行鸡产蛋性能的影响。本研究使用RT-PCR对43周龄健康太行鸡FST基因编码区序列进行克隆和测序，运用生物信息学软件对其功能结构进行预测，荧光定量PCR技术对43周龄健康麻羽太行鸡FST在不同组织及不同发育时期卵泡中的表达差异进行分析，每组设3个重复，进行3次平行试验。结果显示，太行鸡FST基因编码区为1 032 bp，编码343个氨基酸，太行鸡FST蛋白与日原鸡同源性最高（100.0%），存在Sec信号肽，成熟蛋白具有FOLN和KAZAL_FS 2个保守结构域。该蛋白为亲水蛋白，蛋白分子式为C₁₆₁₉H₂₅₆₇N₄₅₉O₅₂₀S₄₄，分子量为38.192 6 ku，理论等电点为5.59，其中含量最高的是Cys （C），为10.50%；蛋白质二级结构含有α-螺旋、延伸链、β转角、无规卷曲，占比分别为16.33%、16.62%、5.25%、61.81%。FST基因在不同组织中均有表达，在肝中表达量最高。FST基因在各级卵泡表达量存在差异，其中，在大白卵泡中表达量最高（P<0.01），在卵泡选择前后表达量存在1.6倍表达差异。上述结果为研究太行鸡FST基因结构和功能提供了重要的基础数据，也为进一步挖掘太行鸡产蛋性能候选高产基因提供了参考。

Cloning,Bioinformatics and Expression Analysis of FST Gene in Taihang Chickens

Follistatin (FST) gene of Taihang chicken was analyzed by bioinformatics methods and its expression differences in different tissues and follicles at different developmental stages was explored, and the effect of FST on the laying performance of Taihang chickens was analyzed. Coding region of FST gene was cloned and sequenced for 43-week-old healthy Taihang chicken, functional structure was predicted by bioinformatics softwares. Quantitative PCR (Q-PCR) was used to detect the expression differences of FST gene in different tissues and follicles at different developmental stages of Taihang chickens. Three replicates were set in each group and three parallel experiments were carried out. The results showed that the coding region of FST gene of Taihang chicken was 1 032 bp, encoding 343 amino acids. Homology analysis indicated that FST protein had the highest homology with Gallus gallus (100.0%), and both had Sec signal peptide. The mature protein had two conserved domains: FOLN and KAZAL_FS. Physicochemical properties analysis of FST protein showed that it was hydrophilic protein, whose molecular formula was C₁₆₁₉H₂₅₆₇N₄₅₉O₅₂₀S₄₄, molecular weight was 38.192 6 ku, and theoretical isoelectric point was 5.59, the highest content was Cys (C, 10.50%). The secondary structure consisted of α-helix, extended chain, β-corner and random coil, accounting for 16.33%, 16.62%, 5.25% and 61.81%, respectively. qPCR revealed that FST gene was expressed in all tissues, the highest expression was found in liver. During follicle development, FST gene was expressed highest in the large white follicles (P<0.01), there was a 1.6-fold difference in expression before and after follicle selection. These results provided important basic data for studying FST gene in Taihang chicken, and provided a reference for the further mining candidate gene for egg-laying performance of hens.