Karyotypic differentiation through chromosome fusion and number reduction in Imparfinis hollandi (Ostariophysi, Heptapteridae)

Genetics and Molecular Biology

Vladimir Pavan Margarido²  Orlando Moreira-filho¹ 

[1] ,Universidade Estadual do Oeste do Paraná Centro de Ciências Biológicas e da Saúde Cascavel PR ,Brazil

关键词: Siluriformes;    chromosome banding;    chromosomal rearrangements;    (TTAGGG)n;   

DOI  :  10.1590/S1415-47572008000200012

来源: SciELO

【 摘 要 】

The Neotropical Heptapteridae fish Imparfinis hollandi, endemic to the Iguaçu River Basin (Brazil), was cytogenetically analyzed and the diploid chromosome number of 2n = 42 chromosomes was determined (22m + 10sm + 10st), the lowest diploid number in this genus and family. Like other Heptapteridae species, only one NOR-bearing chromosome pair was detected by silver nitrate staining. Dark heterochromatic blocks were visualized in only three chromosome pairs, and chromomycin A3+ bands were coincident with Ag-NORs. Although no intercalary (TTAGGG)n sequence was observed through FISH with a telomere probe, an asymmetric karyotype showing four large chromosome pairs with diploid chromosome number reduction suggests that tandem chromosome fusions probably occurred during the karyotypic differentiation of Imparfinis hollandi.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License