Daniel-Silva M F Z, Almeida-Toledo L F
Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, SP, Brazil.
Cytogenet Genome Res. 2005;109(4):497-501. doi: 10.1159/000084209.
A comparison of R-banding patterns obtained by 5-bromodeoxyuridine incorporation was made between the chromosomes of two fish species of the genus Astyanax (Characiformes: Tetragonopterinae), A. altiparanae with 2n = 50 chromosomes, and A. schubarti with 2n = 36 chromosomes. The two species present the highest and the lowest chromosome numbers found in this fish genus, respectively, for which the modal chromosome number is 50. R-band homeology was detected, involving eleven chromosomes of A. schubarti and seventeen chromosomes of A. altiparanae, indicating a close chromosomal relationship between the two species, in spite of their great difference in chromosome number. A chromosome fusion in the past history of the group was hypothesized as a possible cause of the discrepant chromosome numbers of the two species.
通过5-溴脱氧尿苷掺入获得的R带模式，在丽脂鲤属（脂鲤目：四方丽脂鲤亚科）的两种鱼类染色体之间进行了比较，即具有2n = 50条染色体的高鳍丽脂鲤和具有2n = 36条染色体的舒氏丽脂鲤。这两个物种分别呈现出该鱼类属中发现的最高和最低染色体数，其众数染色体数为50。检测到R带同源性，涉及舒氏丽脂鲤的11条染色体和高鳍丽脂鲤的17条染色体，这表明尽管这两个物种的染色体数差异很大，但它们之间存在密切的染色体关系。推测该类群过去的历史中发生过一次染色体融合，这可能是两个物种染色体数不同的原因。
