明尼苏达被毛孢中活跃扩张的HmHeli1转座元件

发布时间：2018-05-13 14:52

本文选题：明尼苏达被毛孢 + HmHeli　；参考：《菌物学报》2017年10期

【摘要】：Helitron是真核生物中存在的一种以滚环方式进行复制的转座元件,关于其对动植物基因组的影响已有深入分析,而在真菌中则鲜有报道。本文对大豆囊孢线虫的生防菌——明尼苏达被毛孢Hirsutella minnesotensis中的Helitron转座元件进行了系统分析,发现该真菌中存在两类自主的Helitron元件HmHeli1和HmHeli2;其中HmHeli1不仅具有保守的末端序列和结构,而且编码序列高度相似,甚至完全一致的Rep Hel转座酶,表明其在基因组中发生了近期扩张并依旧活跃。HmHeli1符合Helitron2元件的结构及编码特征:5′和3′末端分别存在保守序列"TCAG"和"TATTTT",3′末端存在富含GC的发卡结构,近末端存在不对称的反向重复序列;编码的转座酶包含锌指、Rep和Helicase结构域,但不包含核酸内切酶结构域。HmHeli1优先同向插入基因富集区,甚至功能基因内部,插入位点存在一个短的富含AT的序列。HmHeli1不具主动捕获基因的能力,但可被动接受其他转座元件的插入。HmHeli1是一种结构独特、极具扩张力的DNA转座元件,不仅在明尼苏达被毛孢基因组进化中发挥着重要作用,并且具有开发为通用遗传分析工具的潜能。
[Abstract]:Helitron is a kind of transposable element in eukaryote which is copied by rolling loop. The effect of Helitron on the genome of plant and animal has been deeply analyzed, but rarely reported in fungi. In this paper, the Helitron transposition element in Hirsutella minnesotensis, Minnesota coat, which is a biocontrol bacterium of Soybean cyst nematode, was systematically analyzed. It was found that there are two kinds of independent Helitron elements HmHeli1 and HmHeli2 in this fungus, in which HmHeli1 not only has conserved terminal sequence and structure, And the highly similar, or even identical, Rep Hel transposes, This indicates that the genome has recently expanded and is still active. HmHeli1 conforms to the structure and coding characteristics of the Helitron2 element. There are conserved sequences "TCAG" and "TATTTT" at the ends of "TCAG" and "TATTTT", respectively. There are asymmetric reverse repeats at the near end. The transposase encodes zinc finger rep and Helicase domains, but does not contain nucleic acid endonuclease domain. HmHeli1 preferentially inserts into gene rich region, even within functional gene. The insertion site has a short AT-rich sequence. HmHeli1 does not have the ability to actively capture genes, but can passively accept the insertion of other transposable elements. HmHeli1 is a DNA transposable element with unique structure and high expansion force. It not only plays an important role in the evolution of Minnesota trichoderma genome, but also has the potential to be developed as a general genetic analysis tool.
【作者单位】：旱区作物逆境生物学国家重点实验室西北农林科技大学生命科学学院植物保护学院;
【基金】：中央高校基本科研业务费专项(2014YB032) 宁陕科技合作项目~~
【分类号】：S476.1

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