Kretschmer Rafael, de Oliveira Thays Duarte, de Oliveira Furo Ivanete, Oliveira Silva Fabio Augusto, Gunski Ricardo José, Del Valle Garnero Analía, de Bello Cioffi Marcelo, de Oliveira Edivaldo Herculano Corrêa, de Freitas Thales Renato Ochotorena
Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, RS, Brazil.
Programa de Pós-Graduação em Ciências Biológicas, PPGCB, Universidade Federal do Pampa, São Gabriel, Rio Grande do Sul, RS, Brazil.
Genet Mol Biol. 2018 Jan-Mar;41(1):98-106. doi: 10.1590/1678-4685-GMB-2017-0048. Epub 2018 Feb 19.
An extensive karyotype variation is found among species belonging to the Columbidae family of birds (Columbiformes), both in diploid number and chromosomal morphology. Although clusters of repetitive DNA sequences play an important role in chromosomal instability, and therefore in chromosomal rearrangements, little is known about their distribution and amount in avian genomes. The aim of this study was to analyze the distribution of 11 distinct microsatellite sequences, as well as clusters of 18S rDNA, in nine different Columbidae species, correlating their distribution with the occurrence of chromosomal rearrangements. We found 2n values ranging from 76 to 86 and nine out of 11 microsatellite sequences showed distinct hybridization signals among the analyzed species. The accumulation of microsatellite repeats was found preferentially in the centromeric region of macro and microchromosomes, and in the W chromosome. Additionally, pair 2 showed the accumulation of several microsatellites in different combinations and locations in the distinct species, suggesting the occurrence of intrachromosomal rearrangements, as well as a possible fission of this pair in Geotrygon species. Therefore, although birds have a smaller amount of repetitive sequences when compared to other Tetrapoda, these seem to play an important role in the karyotype evolution of these species.
在鸟纲鸽形目鸠鸽科的物种中，发现了广泛的核型变异，包括二倍体数目和染色体形态。尽管重复DNA序列簇在染色体不稳定性以及因此在染色体重排中起重要作用，但关于它们在鸟类基因组中的分布和数量却知之甚少。本研究的目的是分析11种不同微卫星序列以及18S rDNA簇在9种不同鸠鸽科物种中的分布，并将它们的分布与染色体重排的发生相关联。我们发现二倍体数目在76到86之间，并且在分析的物种中，11种微卫星序列中有9种显示出明显的杂交信号。微卫星重复序列的积累优先出现在宏观和微观染色体的着丝粒区域以及W染色体上。此外，第2对染色体在不同物种中以不同组合和位置显示出多个微卫星的积累，这表明发生了染色体内重排，以及在Geotrygon属物种中这一对染色体可能发生了分裂。因此，尽管与其他四足动物相比，鸟类的重复序列数量较少，但这些序列似乎在这些物种的核型进化中起重要作用。
