金小蜂bHLH转录因子家族成员的鉴定与分析

发布时间：2018-07-04 10:27

本文选题：金小蜂 + bHLH转录因子　；参考：《江苏大学》2016年硕士论文

【摘要】：碱性螺旋-环-螺旋(basic helix-loop-helix,b HLH)基序是蛋白质中高度保守的可以结合DNA的结构域。含有b HLH基序的蛋白质组成了一个转录因子超家族,其家族成员广泛存在于动、植物以及真菌等真核生物中,在细胞增殖与分化、神经细胞产生和性别决定等一系列重要发育过程中发挥调控作用。b HLH基序长约60个氨基酸,含有一个碱性区域(用于结合DNA)和由一个不定长度的环状区域连接的两个螺旋区域(促进二聚化)。动物b HLH转录因子根据其功能特征被分成45个家族,而这45个家族中的b HLH转录因子又根据其自身结构特点和所作用的DNA元件被分为A、B、C、D、E和F六个高阶组(high-order group)。金小蜂(jewel wasp,Nasonia vitripennis)属于膜翅目昆虫,为寄生蜂,是农作物害虫的天敌。此外,金小蜂也是一种重要的昆虫模式生物,在复杂特征分析、发育遗传学、进化遗传学等研究中得到广泛应用。弄清金小蜂中具有哪些b HLH转录因子家族成员将有助于深入了解金小蜂生长发育过程以及特殊生理生化特征产生的机理。本研究运用Blast搜索、多序列比对、系统发生分析等生物信息学手段对金小蜂基因组中编码的b HLH转录因子家族成员进行了全面的鉴定与分析,获得了如下结果:1、从金小蜂基因组内成功地鉴定出了48个b HLH家族成员,根据组内进化分析结果将这48个b HLH家族成员归入了36个家族和6个高阶组,其中A、B、C、D、E和F六个组中分别有19、12、9、1、6和1个成员。2、蛋白质数据库搜索显示,在鉴定出的48个金小蜂b HLH家族成员中,有21个成员的注释与本研究结果一致,有17个成员的注释与本研究结果不一致,8个成员注释为预测蛋白,2个成员没有注释。因此,本研究为27个金小蜂b HLH家族成员蛋白序列进行更为准确的注释提供了有用信息。3、通过与其它昆虫中b HLH家族成员的分布情况进行比较,发现金小蜂中在Net、Myo Ra和PTFa三个家族中没有b HLH成员,而其它十种昆虫在这三个家族中都有一个甚至两个成员。这些b HLH家族成员的缺失是否与金小蜂的独特生长发育过程有关有待进一步探讨。4、运用电子克隆方法绘制出了29个金小蜂b HLH基因的结构图,其中19个基因的结构较为完整,主要是有转录起始位点但没有poly(A)尾;剩余的10个基因的结构是不完整的,主要是没有转录起始位点和poly(A)尾。本研究所获得的结果为今后进一步研究b HLH转录因子在金小蜂生长发育中的调控机理提供了有用的背景资料,也为开展不同昆虫b HLH基因结构与功能的比较研究打下了良好基础。
[Abstract]:The basic helix-loop-helixlb HLH motif is a highly conserved DNA-binding domain in proteins. Proteins containing bHLH motifs form a transcriptional factor superfamily whose members are widely found in eukaryotes, such as animals, plants and fungi, in cell proliferation and differentiation. During a series of important developmental processes such as neuronal production and sex determination, the. BHLH motif is about 60 amino acids. It contains an alkaline region (used for binding DNA) and two helical regions (promoting dimerization) connected by a ring region of indefinite length. Animal bHLH transcription factors are divided into 45 families according to their functional characteristics, and the b HLH transcription factors of these 45 families are divided into six higher order groups (high-order group).) according to their own structural characteristics and acting elements. Jewel Waspa vitripennis belongs to Hymenoptera and is a parasitoid, which is the natural enemy of crop pests. In addition, it is also an important insect model organism, which has been widely used in complex characteristic analysis, developmental genetics, evolutionary genetics and so on. It will be helpful to understand the growth and development process and the production mechanism of special physiological and biochemical characteristics of Jumblebee by knowing which members of the bHLH transcription factor family exist in the honeybee. In this study, bioinformatics methods, such as blast search, multiple sequence alignment and phylogenetic analysis, were used to identify and analyze the members of the bHLH transcription factor family encoded in the genomes of the wasp. The following results were obtained: 1, 48 members of the b-HLH family were successfully identified from the genome of the wasp, and the 48 members of the b-HLH family were classified into 36 families and 6 higher order groups according to the results of intra-group evolution analysis. The protein database search showed that 21 of the 48 identified members of the bHLH family were consistent with the results of the present study. 17 members' comments were inconsistent with the results of this study, 8 members were annotated as predictive proteins and 2 members were not annotated. Therefore, this study provides useful information for the more accurate annotation of the protein sequences of 27 members of the bHLH family, and compared with the distribution of the members of the bHLH family in other insects. It was found that there were no bHLH members in the three families of Myo Ra and PTFa, while the other ten insects had one or two members in the three families. Whether the deletion of these members of the bHLH family is related to the unique growth and development process of the wasp needs to be further explored. By using the electronic cloning method, the structural maps of 29 bHLH genes were drawn, 19 of which were relatively complete in structure. The structure of the remaining 10 genes was incomplete, with no transcriptional initiation site and poly (A) tail. The results provided useful background data for the further study of the regulation mechanism of bHLH transcription factors in the growth and development of wasp. It also laid a good foundation for the comparative study of the structure and function of different insect bHLH genes.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S476.3;Q78

【相似文献】