单 位：
广州市昆虫发育与应用重点实验室华南师范大学生命科学学院昆虫科学与技术研究所
关键词：
家蚕基因组;G-四链体;核酸代谢调控;信号转导
摘 要：
G-四链体(G-quadruplex,G4)是一种不同于双螺旋的特殊结构,由富含鸟嘌呤的DNA链在阳离子的参与下形成的四链DNA螺旋高级结构,在哺乳动物中被证明是具有重要生物学功能的表观遗传学元件。以鳞翅目模式昆虫家蚕(Bombyx mori)为对象,利用Quadparser程序,在家蚕全基因组范围预测G4结构,对其分布特征以及对其潜在调控基因的表达特性和功能的影响进行初步分析。在家蚕全基因组共预测到6 278个G4结构,其中有63.5%位于转座子区,35.3%分布在编码基因区。在基因的5'端侧翼序列转录起始位点和3'端转录终止位点附近都有相对明显的G4结构富集,暗示G4结构可能对于基因表达具有一定的调控作用。相对于基因组背景,上游含有G4结构的基因其编码区长度偏短,下游含有G4结构的基因其编码区则显著加长。上游含有G4结构的基因主要富集于核酸结合活性尤其是转录因子活性分子功能上,主要参与核酸代谢相关的调控过程,G4结构主要位于编码链;下游含G4结构的基因则主要富集于激酶和转移酶活性以及受体活性分子功能上,主要参与蛋白质加工及信号转导过程,G4结构主要位于模板链。上述结果提示G4结构位于基因上、下游所调控的靶基因有所分歧,作用机制可能也有所差异。结合家蚕基因组芯片数据分析发现,含有G4结构的基因没有明显的组织表达特异性,提示该类基因在广泛的生物学过程中均发挥作用。以上结果为后续深入研究该类表观遗传学结构在家蚕中的生物学功能提供了重要线索和参考依据。
译 名：
Genomic Survey on Distribution of G-quadruplex Motifs and Their Functional Implications in Bombyx mori
作 者：
Wu Feng;Xiang Hui;Feng Qili;Guangzhou Key Laboratory of Insect Development and Application,Institute of Insect Science and Technology,School of Life Sciences,South China Normal University;
关键词：
Bombyx mori genome;;G-quadruplex;;Regulation of nucleic acid metabolism;;Signal transduction
摘 要：
G-quadruplex( G4) is a kind of special four-strand structure different from the double helix structure of DNA. It is formed from guanine-rich sequences,which is stabled by monovalent cation. In mammals,G4 motif has been proven to be an epigenetic element with important biological functions. Quadparser program was run to predict G4 motifs in whole genome of the Lepidoptera model insect silkworm( Bombyx mori). Furthermore,distribution features of G4 motifs and regulatory effects of G4 motifs on target gene expression and function were preliminarily analyzed.Totally 6 278 G4 motifs were identified in silkworm whole genome. 63. 5% of them are located in transposable element regions, and 35. 3% of them are distributed in coding gene regions. There are relatively enriched G4 structures near the 5' flanking region of transcription initiation site and the 3' transcriptional termination site,suggesting that G4 structures may play roles in regulation of gene expression. Compared to the genomic background,genes harboring G4 motifs at the 5' flanking regions tend to have shorter coding regions while those with G4 motifs at 3'flanking regions tend to have longer coding regions. Furthermore,genes with 5' flanking sequence bearing G-quadruplex are enriched in molecular function of nucleic acid binding especially of transcription factor activity. These genes are mainly involved in regulation of nucleic acid metabolism related processes. Their G4 structures are mainly located on coding strand. Genes with 3' flanking sequence bearing G-quadruplex are mainly enriched in molecular function of kinase,transferase and receptor activities. These genes are mainly involved in protein processing,phosphorylation modification and signal transduction. Their G4 structures are mainly located on template strand. The above results suggest that G4 structures located upstream or downstream of genes have different regulatory roles on target genes,and their functioning mechanisms may also be different. Combined analysis with the microarray data of silkworm,we found that genes with G4 motifs didn't show obvious tissue expression specificity,indicating that G4 motif regulated genes are involved in wide range of biological processes. This preliminary investigation provides important clues and references for further study on the biological function of this epigenetic genetic structure in silkworm.
