Comparative Cytogenetics of Hoplerythrinus unitaeniatus (Agassiz, 1829) (Characiformes, Erythrinidae) Species Complex from Different Brazilian Hydrographic Basins

作者：Martinez Juliana F^*; Lui Roberto L; Traldi Josiane B; Blanco Daniel R; Moreira Filho Orlando

来源：Cytogenetic and Genome Research, 2016, 149(3): 191-200.

DOI：10.1159/000448153

• Chromosome banding
• Fish cytogenetics
• Fish cytotaxonomy
• NORs
• rDNA FISH

Chromosomal characteristics of Hoplerythrinus unitaeniatus populations from 5 Brazilian river basins, namely Arinos (Amazonas basin), Araguaia, Paraguai, Alto Parana, and Sao Francisco were analyzed by conventional Giemsa staining, C-banding, silver nitrate impregnation, and fluorescence in situ hybridization (FISH) with 185 and 55 rDNA and telomeric sequence (TTAGGG)(n) probes. The diploid chromosome number was 2n = 48 in representatives of the populations from Paraguai and Alto Parana River basins and 2n = 52 for those from the Arinos and Araguaia River basins. The Sao Francisco population had individuals with 2n = 50 and 52 occurring in sympatry. C-banding showed heterochronnatic blocks mainly located at interstitial and pericentromeric positions in most of the chromosomes. Silver nitrate impregnation demonstrated simple NORs for representatives from Arinos and Araguaia River populations and multiple NORs for specimens from Paraguai, Alto Parana, and Sao Francisco River populations. FISH with 185 and 5S rDNA probes revealed many chromosomes carrying these cistrons, with up to 21 chromosomes bearing 18S rDNA sites (Alto Rio Parana basin) and up to 12 chromosomes with 5S rDNA sites (Paraguai basin), besides the occurrence of colocalization in all populations. FISH with telomeric sequence (TTAGGG)(n), detected sites in the terminal portion of the chromosomes in all populations, These data reinforce the idea that H. unitaeniatus is a species complex. Evolutionary and biogeographical aspects of the group in the Neotropical region are discussed.

• 出版日期2016