目录
摘 要III
关键词III
AbstractIV
引言
引 言1
1材料与方法3
1.1蛋白库的获取 3
1.2 6mA甲基转移酶基因的搜索3
1.3 6mA甲基转移酶的序列比对和系统进化树构建3
1.4 6mA甲基转移酶的保守结构域和motif结构分析3
1.5 森林草莓6mA甲基转移酶基因染色体定位3
1.6 森林草莓6mA甲基转移酶基因在花和果实发育成熟过程、冷热胁迫时表达分析3
1.7 森林草莓材料的处理与采样、RNA提取和实时荧光定量PCR4
2结果与分析7
2.1 6mA甲基转移酶基因的鉴定7
2.2 6mA甲基转移酶MTA70蛋白家族的关键结构域、motif鉴定和进化分析 7
2.3 6mA甲基转移酶DAMT蛋白家族的关键结构域、motif鉴定和进化分析9
2.4 MTA70和DAMT基因染色体定位9
2.5 森林草莓中MTA70和DAMT基因在花和果实发育过程中的表达模式分析9
2.6 低温和高温胁迫中森林草MTA70和DAMT基因的表达分析12
3讨论15
致 谢17
参考文献19
森林草莓6mA甲基转移酶基因鉴定及功能分析
摘 要
通过生物信息学手段，鉴定出森林草莓(Fragaria vesca) 基因组中两类可能的6mA甲基转移酶基因(3个MTA70、2个DAMT基因)。对细菌、真菌、动物和植物中的6mA甲基转移酶基因的系统进化分析及染色体定位表明，森林草莓MTA70基因可分为3个亚家族，且在动、植物分化前就已经存在；两个DAMT基因由物种特异的串联重复产生，且结构变化快，推测其在进化历程中功能发生了分化。转录组数据及实时定量荧光PCR分析显示，各个基因均具有时空表达特异性和非生物胁迫响应。其中1个DAMT基因表达量在果实中较高且随果实成熟上调，推测可能参与调控果实成熟。此外，这5个在冷胁迫下表达水平有不同程度下调 *51今日免费论文网|www.51jrft.com +Q: ￥351916072￥ 
；而在热胁迫下随着胁迫时间而有显著变化。由此推测6mA甲基转移酶基因可能参与了森林草莓的生长发育和对冷、热胁迫的响应。
IDENTIFICATION AND FUNCTIONAL ANALYSIS OF N6ADENINE METHYLATION (6MA) METHYLTRANSFERASE GENES IN FRAGARIA VESCA
ABSTRACT
DNA methylation on the sixth position of the purine ring in adenine [N6methyladenine (6mA)] is an epigenetic modification widely present in both eukaryotes and prokaryotes, but our understanding in its function in plants is limited. We applied bioinformatic approaches to identify and analyze the two classes of putative N6adenine DNA methyltransferase genes (three MTA70 and two DAMT genes) in woodland strawberry Fragaria vesca. Phylogenetic analysis and chromosome positioning on those 6mA DNA methyltransferase genes from bacteria, fungi, animals and plants showed that Fragaria vesca MTA70 genes could be classified into three subfamilies, which existed before the diversification of plants and animals. Two DAMT genes were generated by a speciesspecific tandem duplication, and the proteins structure changed rapidly. It is speculated that the function of the DAMT protein has diversified during the evolutionary process. The analysis on transcriptome data and quantitative real time PCR suggested that each gene had specific spatiotemporal expression and was responsive to cold and heat stresses. The expression of one DAMT gene was relatively higher in fruits and was upregulated as fruit matured, indicating that it may participate in the regulation of fruit ripening. In addition, the expression levels of the five 6mA methyltransferase genes were significantly changed under cold and heat stresses. Thus, it is speculated that MTA70 and DAMT genes may be involved in the growth and development of Fragaria vesca and its responses to cold and heat stresses.

原文链接：http://www.jxszl.com/nongxue/yy/607226.html