Carvalho K A, Garcia P C A, Recco-Pimentel S M
Departamento de Anatomia, Biologia Celular e Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil.
Genet Mol Res. 2009 Dec 18;8(4):1498-508. doi: 10.4238/vol8-4gmr697.
Four species of Aplastodiscus and two species of Hypsiboas were cytogenetically compared. Aplastodiscus perviridis, A. cochranae, H. albomarginaus, and H. faber had 2n = 24 chromosomes, while A. albosignatus and A. leucopygius had 2n = 20 and 2n = 18 chromosomes, respectively. Aplastodiscus perviridis and A. cochranae had identical karyotypes, as indicated by their chromosomal morphology, the location of the nucleolus organizer region (NOR) on chromosome pair 12, and the heterochromatin pattern. The NOR-bearing chromosomes of A. albosignatus and A. leucopygius (pair 9) were very similar in size and morphology (metacentric) when compared to A. perviridis and A. cochranae (pair 12) and to H. faber (pair 11); the NOR of these chromosomes also occurred in the same region, suggesting that these chromosomes are homologous. Although H. albomarginatus differs from the other species with regard to the location of its NOR on pair 2, this species had the same diploid number and a chromosomal morphology similar to that of A. perviridis and A. cochranae. Chromosomal differentiation among the species appears to have occurred by reduction in chromosome number.
对四种泡蟾属物种和两种叶泡蛙属物种进行了细胞遗传学比较。绿泡蟾、科氏泡蟾、白缘叶泡蛙和费氏叶泡蛙有2n = 24条染色体，而白线泡蟾和白腰泡蟾分别有2n = 20条和2n = 18条染色体。绿泡蟾和科氏泡蟾具有相同的核型，这从它们的染色体形态、第12对染色体上核仁组织区（NOR）的位置以及异染色质模式可以看出。与绿泡蟾和科氏泡蟾（第12对）以及费氏叶泡蛙（第11对）相比，白线泡蟾和白腰泡蟾的含NOR染色体（第9对）在大小和形态（中着丝粒）上非常相似；这些染色体的NOR也出现在同一区域，表明这些染色体是同源的。尽管白缘叶泡蛙的NOR位于第2对染色体上，与其他物种不同，但该物种的二倍体数目相同，且染色体形态与绿泡蟾和科氏泡蟾相似。物种间的染色体分化似乎是通过染色体数目的减少而发生的。
