猪DNA甲基转移酶基因家族进化分析

【目的】 探究猪DNA甲基转移酶（DNMT）基因家族的基因特性及表达模式。【方法】 利用生物信息学方法鉴定猪全基因组范围的DNMT基因家族,并对其染色体定位、理化性质、蛋白质结构、亚细胞定位、基因结构、保守基序、系统进化关系、共线性关系和基因表达模式进行分析。【结果】 共鉴定得到5个猪DNMT基因家族成员：PigDNMT1、PigDNMT2、PigDNMT3、PigDNMT4和PigDNMT5,分别位于2、3、13、14、17号染色体上。猪DNMT基因家族进化树分析发现,PigDNMT1和PigDNMT4、PigDNMT2和PigDNMT5的亲缘关系较近。PigDNMT2和PigDNMT5具有相同数量和排列顺序的保守基序,但在基因结构上差异较大。系统进化树结果揭示,猪、人、小鼠和牛的DNMT基因家族分为4个亚族,其中猪与牛的DNMT基因家族亲缘关系更近。基因共线性分析显示,猪与人、小鼠、牛之间都具有4对直系同源DNMT基因,表明4个物种的DNMT基因间存在较强的共线性关系。猪DNMT家族蛋白长度在228~1 706个氨基酸之间,分子质量在26 133.32~192 267.80 u之间,等电点在6.00~9.06之间。二级结构预测分析结果显示,猪DNMT蛋白主要由无规则卷曲组成。亚细胞定位分析发现,5个猪DNMT蛋白定位于细胞核。母猪性腺轴的转录组数据分析发现,PigDNMT1在下丘脑、垂体和卵巢组织中随着初情启动过程而展现出不同的表达模式。【结论】 本研究在猪基因组上共鉴定出5个DNMT基因,并发现性腺轴组织中的PigDNMT1在初情启动过程中呈现出不同的表达模式,为解析猪DNMT基因家族功能提供一些参考。

Evolutionary Analysis of DNA Methyltransferase Gene Family in Pig

【Objective】 The purpose of this study was to investigate the gene characteristics and expression patterns of DNA methyltransferase (DNMT) gene family in pig.【Method】 Bioinformatics methods were used to identify members of porcine DNMT gene family at the whole genome level, and the chromosomal localization, physicochemical properties, protein structure, subcellular localization, gene structure, conserved motif, phylogenetic relationship, collinear relationship and expression pattern of DNMT gene were analyzed.【Result】 A total of five porcine DNMT genes:PigDNMT1, PigDNMT2, PigDNMT3, PigDNMT4 and PigDNMT5, were identified, which were distributed on chromosomes 2, 3, 13, 14 and 17, respectively.Phylogenetic tree analysis of porcine DNMT gene family found that PigDNMT1 and PigDNMT4, as well as PigDNMT2 and PigDNMT5 displayed closer relationships.PigDNMT2 and PigDNMT5 were identical in number and order of motifs, but differ in gene structure.Phylogenetic tree analysis revealed that the DNMT gene family of pig, human, mouse and cattle were divided into four subfamilies, among which the DNMT gene family of pig and cattle displayed closer relationships.Gene collinearity analysis showed that there were four pairs of orthologous genes for DNMT in pig, human, mouse and cattle, indicating that there was a strong collinear relationship among the DNMT genes of the four species.Lengths of DNMT family protein in pig varied from 228 to 1 706 amino acids, and the molecular weight of DNMT proteins varied from 26 133.32 to 192 267.80 u, and the isoelectric points of DNMT protein varied from 6.00 to 9.06.Analysis of secondary structure prediction showed that DNMT proteins of pig were mainly composed of random coils.Subcellular localization analysis found that all DNMT genes of pig were located in the nucleus.Transcriptome analysis of sow gonadal axis found that PigDNMT1 showed different expression patterns in the hypothalamus, pituitary and ovary during the onset of puberty.【Conclusion】 In this study, a total of 5 DNMT genes were identified in pig, and it was found that PigDNMT1 in the gonadal axis showed different expression patterns during the initiation of puberty.This bioinformatics analysis provided some reference for analyzing the function of DNMT gene family in pigs.