Venancio Neto Sebastião, Noleto Rafael Bueno, Azambuja Matheus, Gazolla Camilla Borges, Santos Bianca Rocha, Nogaroto Viviane, Vicari Marcelo Ricardo
Universidade Federal do Paraná, Centro Politécnico, Departamento de Genética, Programa de Pós-Graduação em Genética, Curitiba, PR, Brazil.
Universidade Estadual do Paraná, Departamento de Biologia, União da Vitória, PR, Brazil.
Genet Mol Biol. 2023 Jan 6;45(4):e20220203. doi: 10.1590/1678-4685-GMB-2022-0203. eCollection 2023.
Boana comprises a diverse genus of Neotropical treefrogs, currently rearranged into seven taxonomic species groups. Although cytogenetic studies have demonstrated diversity in its representatives, the chromosomal mapping of repetitive DNA sequences is still scarce. In this study, Boana albopunctata, Boana faber, and Boana prasina were subjected to in situ localization of different repetitive DNA units to evaluate trends of chromosomal evolution in this genus. Boana faber and B. prasina had 2n=24 chromosomes, while B. albopunctata has 2n=22 and an intra-individual variation related to the presence/absence of one B chromosome. The location of 45S rDNA sites was different in the analyzed karyotypes, corroborating with what was found in the distinct phylogenetic groups of Boana. We presented the first description of 5S rDNA in a Boana species, which showed markings resulting from transposition/translocation mechanisms. In situ localization of microsatellite loci proved to be a helpful marker for karyotype comparison in Boana, commonly with cis accumulation in the heterochromatin. On the other hand, genomic dispersion of microsatellites may be associated with hitchhiking effects during the spreading of transposable elements. The obtained results corroborated the independent diversification of these lineages of species from three distinct phylogenetic groups of Boana.
布埃纳属包含多种新热带树蛙，目前已重新划分为七个分类物种组。尽管细胞遗传学研究已证明其代表物种具有多样性，但重复DNA序列的染色体定位研究仍然较少。在本研究中，对白点布埃纳树蛙、费氏布埃纳树蛙和翡翠布埃纳树蛙进行了不同重复DNA单元的原位定位，以评估该属的染色体进化趋势。费氏布埃纳树蛙和翡翠布埃纳树蛙有2n = 24条染色体，而白点布埃纳树蛙有2n = 22条染色体，且存在个体内与一条B染色体的有无相关的变异。在所分析的核型中，45S rDNA位点的位置不同，这与在布埃纳不同系统发育组中发现的情况一致。我们首次描述了布埃纳属一个物种中的5S rDNA，其显示出由转座/易位机制产生的标记。微卫星位点的原位定位被证明是布埃纳属核型比较的一个有用标记，通常在异染色质中呈顺式积累。另一方面，微卫星的基因组分散可能与转座元件传播过程中的搭便车效应有关。所得结果证实了布埃纳三个不同系统发育组中这些物种谱系的独立分化。
