中华绒螯蟹CYP4C基因的分子进化研究

中华绒螯蟹CYP4C基因的分子进化研究(论文7200字)
摘    要
中华绒螯蟹（Eriocheir japonica sinensis）是一类重要的经济蟹类，可同时适应淡水和咸水的生活。然而，关于中华绒螯蟹渗透调节的分子机制一直不是特别清楚。本研究选取渗透调节中的关键基因CYP4C，在中华绒螯蟹和三疣梭子蟹两个物种中进行了对比分析。首先，从NCBI下载十个十足目动物的CYP4C基因的序列，进行系统发生关系的重构。接着，分别将中华绒螯蟹和三疣梭子蟹设置为前景枝，进行选择压力分析。最后，对中华绒螯蟹和三疣梭子蟹中CYP4C基因的表达量进行了检测。研究结果发现，中华绒螯蟹作为前景枝时，检测到了显著的正选择信号（ω2=25.51）。并且，相比于三疣梭子蟹，CYP4C在中华绒螯蟹中有更高的表达量。这些结果，提示中华绒螯蟹中CYP4C基因的功能得到了增强，以便于其更好的适应咸淡水的转换。

关键词：中华绒螯蟹；CYP4C基因；渗透调节；正选择

The molecular evolution of CYP4C gene in the Chinese mitten crab
Abstract
The Chinese mitten crab (Eriocheir japonica sinensis) is a kind of important economic crab which can adapt to both the fresh water and saline water at the same time. However, it’s not very clear about the molecular mechanism of osmotic regulation of Chinese mitten crab. In this study, we selected CYP4C gene which is one of the key genes of osmotic regulation. The Chinese mitten crab and swimming crab (Portunus trituberculatus) has been carried on the comparative analysis of these two species. First, download ten decapoda species’ CYP4C genes sequence from the NCBI website and build the phylogenetic tree. Then, E. j. sinensis and P. trituberculatus are set to prospect branches respectively to selection pressure analysis. Finally, CYP4C genes’ expression quantity of E. j. sinensis and P. trituberculatus were detected. The results of this study showed that E. j. sinensis set as a branch, the positive selection signal is detected significantly (ω2=25.51). By comparing these two species, we found CYP4C gene in the E. j. sinensis has higher expression quantity than P. trituberculatus. The results remind that function of CYP4C gene in the Chinese mitten crab has been enhanced, which means it can adapt to the saline-fresh water transformation.

[资料来源：http://think58.com]

Key words：Chinese mitten crab; CYP4C; Osomoregulatory; Positive selection

目    录
前    言    1
1 材料与方法    3
1.1 构建系统进化树    3
1.1.1 系统发生关系重建的目的    3
1.1.2 系统发生关系重建的方法    3
1.1.3 系统进化树的构建    3
1.2 压力分析    4
1.3 引物设计    4
1.4 qRT-PCR实验    5
1.4.1 实验的动物组织    5
1.4.2 实验试剂    6
1.4.3 实验仪器    6
1.4.4 提取RNA    6
1.4.5 合成cDNA并扩增    7
1.4.6 实时荧光定量PCR    8
2 结果    9
2.1 系统进化树    9
2.2 选择压力分析结果    12
2.3 实时荧光定量PCR结果    13
3 讨论    14 [资料来源：http://www.THINK58.com]
4 结论    15
参考文献    16
致    谢    18