SciELO - Scientific Electronic Library Online

 
vol.23 issue2Aspects of gene regulation in the diploid and tetraploid Odontophrynus americanus (Amphibia, Anura, Leptodactylidae)Study of the karyotype of Oryzoborus maximiliani (Passeriformes - Aves) using young feather pulp cultures author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Genetics and Molecular Biology

Print version ISSN 1415-4757On-line version ISSN 1678-4685

Abstract

MAISTRO, Edson Luis; OLIVEIRA, Claudio  and  FORESTI, Fausto. Sympatric occurrence of two cytotypes of Astyanax scabripinnis (Characiformes, Characidae). Genet. Mol. Biol. [online]. 2000, vol.23, n.2, pp.365-369. ISSN 1415-4757.  https://doi.org/10.1590/S1415-47572000000200021.

Among four specimens of Astyanax scabripinnis sympatrically collected from the Tamanduá stream (State of São Paulo, Brazil), three, named cytotype I, had 2n = 50 chromosomes (6M + 26SM + 4ST + 14A) and a fundamental number (FN) of 86, and one specimen, named cytotype II, had 2n = 48 chromosomes (6M + 28SM + 4ST + 10A) and FN = 86. Besides the difference in diploid number, the cytotypes showed a clear difference in the distribution of constitutive heterochromatin. One NOR-bearing chromosome pair was detected in both cytotypes and one specimen of cytotype I had multiple NORs (tree chromosome pairs). Robertsonian translocations and an increase or loss of heterochromatin are proposed to explain the karyotypic divergence observed. Some aspects related to the chromosome evolution of Astyanax scabripinnis are discussed.

        · abstract in Portuguese     · text in English     · English ( pdf )

 

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