New cases of supernumerary chromosomes in characiform fishes

Pedro Manoel Galetti Junior,Carlos Suetoshi Miyazawa,Paulo Cesar Venere

doi:10.1590/s1415-47571999000300010

Pedro Manoel Galetti Junior, Carlos Suetoshi Miyazawa

Open Access

https://doi.org/10.1590/s1415-47571999000300010

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Abstract

Supernumerary chromosomes were described for five species of Neotropical characiform fishes. These extra chromosomes were small, acrocentric and fully heterochromatic in Leporinus friderici from two different localities as well as in Leporinus sp., but metacentric and fully heterochromatic in Cyphocharax modesta and Prochilodus nigricans. In Characidium cf. zebra, this element was small, acrocentric and euchromatic. GC-rich DNA blocks were observed in the supernumerary chromosome of Leporinus sp. using chromomycin A3. The widespread occurrence of these extra chromosomal elements suggests their independent origins.

Highlights

Among vertebrates there are several descriptions of extra or supernumerary chromosomes, mainly in amphibians, reptiles and mammalians (Jones and Rees, 1982, for review)
Of L. friderici in which the extra chromosomes whenever detected were present in 100% of the analyzed cells, in Leporinus sp. it was observed in about 80% of the cells
In the genus Prochilodus two other species share the presence of extra chromosomes

Summary

Introduction

Among vertebrates there are several descriptions of extra or supernumerary chromosomes, mainly in amphibians, reptiles and mammalians (Jones and Rees, 1982, for review). Their occurrence can be only related to sporadic events, and additional chromosomes might be an individual trait among the remaining individuals of a population. Other cases of extra chromosomes in fish are well known (Venere and Galetti, 1985; Hochberg and Erdtmann, 1988; Oliveira et al, 1988; Foresti et al, 1989; Fenocchio and Bertollo, 1990; Oliveira and Foresti, 1993; Pastori et al, 1997). In some of the B-bearing populations of A. scabripinnis, the B chromosomes appear to be constrained to the highest altitude along the extent of the stream where these fishes inhabit (Vicente et al, 1996)

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