title: Coexistence of cytotypes and chromosomal mosaicism in Hoplias malabaricus (Characiformes, Erythrinidae).
abstract: Karyotypes of seventeen Hoplias malabaricus specimens, collected in the fish culture station of UNOPAR (University of Northern Paraná), were analyzed. The station is in the Claro River system in the Tibagi River basin. Two distinct and coexistent karyotype forms (cytotypes) were identified, comprising either 42 chromosomes (cytotype A) or 40 chromosomes (cytotype C), both presenting metacentric and submetacentric chromosomes. In two specimens, one male and one female, it was not possible to characterize a modal diploid number because different cell lines were observed, with a predominance of 2n=41 and 2n=42 chromosomes at a frequency of 38.24% and 41.12%, respectively. The karyotype with 2n=41 showed some putative monosomic and trisomic chromosomes, while the karyotype with 2n=42 showed 21 chromosomal pairs, similar to cytotype A. RAPD analysis showed that these two specimens have the same band pro file of cytotype A (Nei's genetic identity=92%), discarding a possible hybridization between both cytotypes and supporting the mosaicism hypothesis. These findings corroborate the isolation between cytotypes A and C.
authors.affiliation: Departamento de Biología Geral, Universidade Estadual de Londrina, CEP 86051-990, Caixa Postal 6001, Londrina, Paraná, Brasil.
authors.forename: Renata
authors.initials: R
authors.lastname: Da Rosa
authors.forename: Marceléia
authors.initials: M
authors.lastname: Rubert
authors.forename: Luiz A C
authors.initials: LA
authors.lastname: Bertollo
authors.forename: Isabel C
authors.initials: IC
authors.lastname: Martins-Santos
authors.forename: Lucia
authors.initials: L
authors.lastname: Giuliano-Caetano
mesh_terms: D000818:Animals; D005260:Female; D005399:Fishes / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D009030:Mosaicism / Q000662:veterinary*; D019105:Random Amplified Polymorphic DNA Technique