落叶松-杨栅锈菌基因复制事件及共线性分析

落叶松-杨栅锈菌是一种分布广且危害严重的林木病原真菌。了解基因组内发生的基因复制事件及基因组间的共线性关系,能为最终理解落叶松-杨栅锈菌适应性进化等生物学问题提供帮助。落叶松-杨栅锈菌全基因组水平上基因复制相关研究未见报道,共线性研究报道也较少。本研究利用落叶松-杨栅锈菌全基因组序列分析其基因复制模式。结果表明,落叶松-杨栅锈菌转座复制基因的数目远高于片段复制基因、串联复制基因及相邻复制基因。落叶松-杨栅锈菌基因组内不存在大规模的片段复制,且基因年龄法显示节点同义替换率分布图上没有峰形出现,推断该锈菌未发生全基因组复制。富集分析显示不同类型复制基因富集于不同的功能条目,如串联复制基因富集于碳水化合物的转运和代谢而转座复制基因富集于次生代谢物合成、代谢与分解。共线性分析显示落叶松-杨栅锈菌与松栎柱锈菌及小麦条锈菌的共线性程度均较低,3种锈菌间存在1个共同的共线性区域,该保守区域包含6个基因,其中1个可能编码小分泌蛋白的基因值得关注。

Analyses of gene duplication and synteny in Melampsora larici-populina(Pucciniales,Basidiomycota)

Melampsora larici-populina is a forest pathogenic fungus with wide distribution and serious damage potentials.Analyses of gene duplication modes and syntenic relationship are helpful for us to understand some biological points such as adaptive evolution of M.larici-populina.There are few reports on gene duplications at the whole genome level in M.larici-populina,and limited reports on the concerned synteny research.In this study,referenced genome of M.larici-populina was used to analyze the gene duplication modes.The results indicated that gene number of transposed duplications was higher than that of segment,tandem and proximal duplications in M.larici-populina.We inferred that whole genome duplication did not occur in M.larici-populina,because of no large scale segmental duplications and no peaks found by detecting gene age distributions.The enrichment analysis showed that different duplicated genes were enriched in different functional categories,such as the tandem duplications were enriched in carbohydrate transport and metabolism,while transposed duplications were enriched in secondary metabolite biosynthesis,transport and catabolism.The levels of synteny were low among M.larici-populina,Cronartium quercuum f.sp.fusiforme and Puccinia striiformis f.sp.tritici,and one common synteny block was found among them by synteny analyses.There were six genes located in this conserved region,among which a putative small secreted protein was worthy of paying attention.