Departamento de Genética e Evolução, Laboratório de Citogenética, Universidade Federal de São Carlos, São Carlos, São Paulo 13565-905, Brazil.
J Fish Biol. 2009 Aug;75(2):408-21. doi: 10.1111/j.1095-8649.2009.02333.x.
Constitutive heterochromatin makes up a substantial portion of the genome of eukaryotes and is composed mainly of satellite DNA repeating sequences in tandem. Some satellite DNAs may have been derived from transposable elements. These repetitive sequences represent a highly dynamic component of rapid evolution in genomes. Among the genus Astyanax, the As51 satellite DNA is found in species that have large distal heterochromatic blocks, which may be considered as derived from a transposable DNA element. In the present study, As51 satellite DNA was mapped through in situ fluorescent hybridization in the chromosomes of five species of the genus. The possible roles of this type of saltatory DNA type in the genome of the species are discussed, along with its use for the phylogenetic grouping of the genus Astyanax, together with other shared chromosomal characters. However, the number of As51 clusters is presented as a homoplastic characteristic, thereby indicating evident genomic diversification of species with this type of DNA.
组成型异染色质构成真核生物基因组的大部分，主要由串联重复的卫星 DNA 组成。一些卫星 DNA 可能来自转座元件。这些重复序列代表基因组快速进化的高度动态组成部分。在 Astyanax 属中，As51 卫星 DNA 存在于具有大的远端异染色质块的物种中，这些物种可能是从转座 DNA 元件衍生而来的。在本研究中，通过原位荧光杂交将 As51 卫星 DNA 映射到属的五个物种的染色体上。讨论了这种跳跃式 DNA 类型在物种基因组中的可能作用，以及它与其他共享染色体特征一起用于 Astyanax 属的系统发育分组。然而，As51 簇的数量被认为是同形特征，从而表明具有这种类型 DNA 的物种的基因组明显多样化。
