Abstract
Abstract
Cytogenetic studies in fish of the Rineloricaria genus have already shown a high variation in diploid number (2n). Along with fusion/fission events for 2n alteration, inversions contribute to the diversification of chromosome formulae within this group. The present study assessed different populations/species of the Rineloricaria aiming to describe the karyotype organization of its members and understand the mechanisms that lead to the variation of chromosome numbers. Cytogenetic data showed distinct karyotype organization among Rineloricaria populations/species studied, ranging in diploid number from 46 to 64 chromosomes, syntopic species and two karyomorphs in Rineloricaria pentamaculata. Using ribosomal DNAs (rDNAs) and TTAGGGn probes by fluorescence in situ hybridization in species with low diploid numbers, we detected sites of 18S rDNA, 5S rDNA, and TTAGGGn in centromeric regions of metacentric chromosomes, which participated in chromosome rearrangements like centric fusions. In species with high 2n, centric fissions probably occurred in karyotypic diversification. In this study, we assessed the telomeric instability, chromosomal breaks, and rearrangements due to interstitial telomeric site vestiges detection, in addition to the probable role of rDNAs in chromosome fusions in karyotypic diversification of this group.
Get full access to this article
View all access options for this article.
References
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
