Favarato Ramon Marin, Silva Maelin da, Oliveira Renildo Ribeiro de, Artoni Roberto Ferreira, Feldberg Eliana, Matoso Daniele Aparecida
1 Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva, Instituto Nacional de Pesquisas da Amazônia , Manaus, Brazil .
2 Coordenação de Biodiversidade, Programa de Pós-Graduação em Biologia de Água Doce e Pesca Interior, Instituto Nacional de Pesquisas da Amazônia , Manaus, Brazil .
Zebrafish. 2016 Apr;13(2):103-11. doi: 10.1089/zeb.2015.1140. Epub 2016 Feb 1.
The Ancistrus genus differs from other Ancistrini due to its wide karyotypic diversity, varied diploid numbers, differences in sex chromosomes, and large number of species, as well as its tendency to form small populations with low vagility. This study investigated the role of 5S and 18S rDNA and telomeric repetitive sequences in the evolution of the karyotypic macrostructure of seven species of the genus Ancistrus from the Central Amazon. The results indicate a strong correlation between the location of ribosomal sites and fragile sites in the genome, particularly of 5S rDNA sequences, which are associated, in some species, with telomeric sequences at the sites of chromosomal healing. Moreover, the occurrence of two lineages was observed with regard to the synteny of ribosomal genes. The species of the genus Ancistrus showed high chromosomal lability associated with breakpoints, which was characterized by the presence of repetitive DNA sequences and this process is suggested to be an evolutionary model for the rapid fixation of structural rearrangements.
甲鲶属与其他甲鲶亚科不同，因其具有广泛的核型多样性、多样的二倍体数目、性染色体差异、众多的物种，以及形成低迁移率小种群的倾向。本研究调查了5S和18S rDNA以及端粒重复序列在来自亚马逊中部的七种甲鲶属物种核型宏观结构进化中的作用。结果表明核糖体位点的位置与基因组中的脆弱位点之间存在强烈相关性，特别是5S rDNA序列，在某些物种中，这些序列与染色体愈合部位的端粒序列相关。此外，在核糖体基因的同线性方面观察到两个谱系的存在。甲鲶属物种表现出与断点相关的高染色体不稳定性，其特征是存在重复DNA序列，并且该过程被认为是结构重排快速固定的进化模型。
