Laborne Ana Mattioli, Barrios-Leal Dora Yovana, Heslop-Harrison John S, Manfrin Maura Helena, Kuhn Gustavo C S
Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
Chromosoma. 2024 Dec 10;134(1):1. doi: 10.1007/s00412-024-00827-9.
Satellite DNAs are highly repetitive, tandemly arranged sequences, typically making up large portions (> 20%) of the eukaryotic genome. Most satDNAs are fast evolving and changes in their abundance and nucleotide composition may be related to genetic incompatibilities between species. Here, we used Illumina paired-end sequencing raw data and graph-based read-clustering with the TAREAN bioinformatic tool to study the satDNAs in two cactophilic neotropical cryptic species of Drosophila from the buzzatii cluster (repleta group), D. serido and D. antonietae, from five localities in Brazil. Both species share the same four families of satDNAs: pBuM, DBC-150, CDSTR138 and CDSTR230. They represent less than 4% of the genomic DNA and there are no large differences in the abundance of each satDNA between species. Despite not being the most abundant satDNA, CDSTR138 was found to be associated with most centromeres. All four satDNAs showed instances where repeats are more homogeneous within than between species, a phenomenon known as concerted evolution. On the other hand, there was no evidence for concerted evolution at the population level. Thus, these satDNAs may also be useful as potential markers for species identification. The low levels of satDNA differentiation (both quantitatively as qualitatively) between the two species might be among the reasons that allowed the establishment of a hybrid zone between the two species in the southern coast of Brazil.
卫星DNA是高度重复的串联排列序列，通常占真核生物基因组的很大一部分（>20%）。大多数卫星DNA进化迅速，其丰度和核苷酸组成的变化可能与物种间的遗传不相容性有关。在这里，我们使用Illumina双端测序原始数据，并借助TAREAN生物信息工具基于图的读段聚类，来研究来自巴西五个地点的果蝇嗜仙人掌新热带隐性物种（布扎蒂集群，repleta组）中的两个物种，即D. serido和D. antonietae的卫星DNA。这两个物种共享相同的四个卫星DNA家族：pBuM、DBC - 150、CDSTR138和CDSTR230。它们占基因组DNA的比例不到4%，并且每个卫星DNA在物种间的丰度没有很大差异。尽管CDSTR138不是最丰富的卫星DNA，但发现它与大多数着丝粒相关。所有这四个卫星DNA都显示出重复序列在物种内比在物种间更具同质性的情况，这种现象被称为协同进化。另一方面，在种群水平上没有协同进化的证据。因此，这些卫星DNA也可用作物种鉴定的潜在标记。这两个物种之间卫星DNA分化水平较低（无论是在数量上还是质量上）可能是在巴西南部海岸两个物种之间形成杂交带的原因之一。
