Panabières Franck, Rancurel Corinne, da Rocha Martine, Kuhn Marie-Line
INRAE, UCA, CNRS, ISA Sophia Antipolis, Biot, France.
Front Genet. 2020 Jun 5;11:557. doi: 10.3389/fgene.2020.00557. eCollection 2020.
Satellite DNA is a class of repetitive sequences that are organized in long arrays of tandemly repeated units in most eukaryotes. Long considered as selfish DNA, satellite sequences are now proposed to contribute to genome integrity. Despite their potential impact on the architecture and evolution of the genome, satellite DNAs have not been investigated in oomycetes due to the paucity of genomic data and the difficulty of assembling highly conserved satellite arrays. Yet gaining knowledge on the structure and evolution of genomes of oomycete pathogens is crucial to understanding the mechanisms underlying adaptation to their environment and to proposing efficient disease control strategies. A assembly of the genome of , an important oomycete plant pathogen, led to the identification of several families of tandemly repeated sequences varying in size, copy number, and sequence conservation. Among them, two abundant families, designated as and , displayed typical features of satellite DNA and were collectively designated as . These two satellite families differ by their length, sequence, organization, genomic environment, and evolutionary dynamics. , but not , presented homologs among oomycetes. This observation, as well as the characterization of transcripts of families, suggested that these satellite DNA families likely play a conserved role within this important group of pathogens.
卫星DNA是一类重复序列，在大多数真核生物中以串联重复单元的长阵列形式组织。长期以来被视为自私DNA，现在有人提出卫星序列有助于基因组完整性。尽管它们对基因组的结构和进化有潜在影响，但由于基因组数据匮乏以及组装高度保守的卫星阵列困难，卵菌纲中的卫星DNA尚未得到研究。然而，了解卵菌病原体基因组的结构和进化对于理解其适应环境的机制以及提出有效的疾病控制策略至关重要。对一种重要的卵菌植物病原体的基因组进行组装，导致鉴定出几个串联重复序列家族，它们在大小、拷贝数和序列保守性方面各不相同。其中，两个丰富的家族，分别命名为 和 ，表现出卫星DNA的典型特征，并被统称为 。这两个卫星家族在长度、序列、组织、基因组环境和进化动态方面存在差异。 在卵菌纲中有同源物，而 没有。这一观察结果以及 家族转录本的特征表明，这些卫星DNA家族可能在这一重要的病原体群体中发挥保守作用。
