INRA, UR1264 MycSA, F-33882 Villenave d'Ornon, France.
Fungal Genet Biol. 2013 Jun;55:6-21. doi: 10.1016/j.fgb.2013.04.003. Epub 2013 Apr 20.
Repetitive DNA elements are ubiquitous constituents of eukaryotic genomes. The biological roles of these repetitive elements, supposed to impact genome organization and evolution, are not completely elucidated yet. The availability of whole genome sequence offers the opportunity to draw a picture of the genome-wide distribution of these elements and provide insights into potential mechanisms of genome plasticity. The present study uses in silico approaches to describe tandem repeats and transposable elements distribution in the genome of the button mushroom, Agaricus bisporus. Transposable elements comprised 12.43% of the assembled genome, and 66% of them were found clustered in the centromeric or telomeric regions. Methylation of retrotransposon has been demonstrated. A total of 1996 mini-, 4062 micro-, and 37 satellites motifs were identified. The microsatellites appeared widely and evenly spread over the whole genome sequence, whereas the minisatellites were not randomly distributed. Indeed, minisatellites were found to be associated with transposable elements clusters. Telomeres exhibited a specific sequence with a T(n)AG(n) signature. A comparison between the two available genome sequences of A. bisporus was also performed and sheds light on the genetic divergence between the two varieties. Beyond their role in genome structure, repeats provide a virtually endless source of molecular markers useful for genetic studies in this cultivated species.
重复 DNA 元件是真核生物基因组的普遍组成部分。这些重复元件的生物学功能，据推测会影响基因组的组织和进化，但尚未完全阐明。全基因组序列的出现提供了描绘这些元件在基因组中分布的机会，并深入了解基因组可塑性的潜在机制。本研究利用计算机方法描述了双孢蘑菇（Agaricus bisporus）基因组中串联重复和转座元件的分布。转座元件占组装基因组的 12.43%，其中 66%被发现聚集在着丝粒或端粒区。已经证明了反转录转座子的甲基化。总共鉴定出了 1996 个小型、4062 个微卫星和 37 个卫星基序。微卫星广泛而均匀地分布在整个基因组序列中，而小卫星则不是随机分布的。实际上，小卫星与转座元件簇有关。端粒表现出特定的序列，具有 T(n)AG(n) 特征。还对双孢蘑菇的两个可用基因组序列进行了比较，揭示了两个品种之间的遗传差异。除了在基因组结构中的作用外，重复序列还为遗传研究提供了几乎无穷无尽的分子标记来源，在这个栽培物种中非常有用。
