摘 要：华鳈（Sarcocheilichthys sinensis）属鲤形目，鲤科，鳈属，具有很好的营养和经济 价值。胰岛素样生长因子(inshulin like growth factors,IGFs)又称生长介素,是一组具有生长 激素依赖性和多种功能的多肽类细胞增殖调控因子，主要包括 IGF-Ⅰ和 IGF-Ⅱ2 类，对机体 的生长发育具有促进作用。本研究采用 RT-PCR 技术，从华鳈中克隆获得 IGF cDNA 序列， 并对其进行了同源性比较和进化分析。结果显示：华鳈 igf1 cDNA 片段长为 838 bp，开放 阅读框长为 486 bp，编码 161 个氨基酸；igf2a cDNA 片段长为 2031 bp，开放阅读框长为603 bp，编码 200 个氨基酸；igf2b cDNA 片段长为 2279 bp，开放阅读框长为 639 bp，编码212 个氨基酸。华鳈 igf 基因与其他近源物种的氨基酸相似性较高，并存在较多氨基酸保守 区域。本研究获得的华鳈 igf 基因序列将为今后在华鳈中开展该基因功能及多态性位点与 分子标记辅助育种等提供基础资料。85853

毕业论文关键词：华鳈，IGF，基因克隆，RT-PCR，氨基酸，序列同源性

Abstract： Sarcocheilichthys sinensis belongs to the Sarcocheilichthys genus of the subfamily Gobioninae in Cyprinidae of Cypriniformes。 and it has good nutritional and economic value。 Insulin-like growth factor (IGF), also known as somatomedin, is a growth hormone dependent polypeptide and a multifunctional cell growth regulating factor, which consists of 2 subgenes IGF- I and IGF- II with functions in promotion of body growth and development。 In this study, the RT-PCR technology was applied to clone cDNA sequences of IGFs in S。 sinensis and the analysis on homology comparison of evolution with related fishes was also carried out。 The results showed that in S。 sinensis, cDNA fragment of igf1 was 838 bp in length with an open reading frame (ORF) of 486 bp which encoded a peptide of 161 amino acids; cDNA length of igf2a was 2031 bp and ORF was 603 bp encoding 200 amino acids; igf2b cDNA was 2279 bp long with an ORF of 639 bp encoding 212 amino acid。 The similarity of S。 sinensis igf amino acid with other fish species was relatively high, and many conserved regions of amino acids were detected。 These IGF sequences obtained in this study will provide basic data for the future studies on gene function analysis, association analysis between polymorphic sites in igfs and growth traits, and molecular marker assisted breeding in Sarcocheilichthys sinensis。

Keywords：Sarcocheilichthys sinensis, IGF, Gene cloning, RT-PCR, Amino acid, Sequence homology

目 录

1 引言 4

1。1 华鳈的概述 4

1。2 胰岛素样生长因子的研究概况 4

1。3 研究目的与意义 5

2 材料与方法 5

2。1 实验材料 5

2。1。1 实验所用仪器 5

2。1。2 实验所用药剂 6

2。1。3 实验样品 6

2。1。4 试剂的配置 6

2。2 实验方法 6

2。2。1 RNA 引物设计 6

2。2。2 RNA 的提取 7

2。2。3 cDNA 第一链的合成 7

2。2。4 华鳈 Igf 基因片段扩增与检测 8

2。2。5 Igf 基因序列扩增与纯化 8

2。2。6 克隆 9

2。2。7 数据分析