Intrapopulation chromosomal polymorphism in mazama gouazoubira (Cetartiodactyla; Cervidae): The emergence of a new species?

Mazama gouazoubira is a small deer species widely distributed in South America. Previous studies have shown that this species presents intraspecific chromosomal polymorphisms, which could affect fertility due to the effects of chromosomal rearrangements on gamete formation. Important aspects regardi...

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Detalhes bibliográficos
Autores: Valeri, Mirela P. [UNESP], Tomazella, Iara M. [UNESP], Duarte, José M.B. [UNESP]
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2018
País:Brasil
Recursos:Universidade Estadual Paulista (UNESP)
Repositório:Repositório Institucional da UNESP
Idioma:inglês
OAI Identifier:oai:repositorio.unesp.br:11449/176181
Acesso em linha:http://dx.doi.org/10.1159/000488377
http://hdl.handle.net/11449/176181
Access Level:Acceso aberto
Palavra-chave:B chromosome
Centric fusion
G-banding
Gray brocket deer
Descrição
Resumo:Mazama gouazoubira is a small deer species widely distributed in South America. Previous studies have shown that this species presents intraspecific chromosomal polymorphisms, which could affect fertility due to the effects of chromosomal rearrangements on gamete formation. Important aspects regarding the karyotype evolution of this species and the genus remain undefined due to the lack of information concerning the causes of this chromosomal variation. Nineteen individuals belonging to the Mazama gouazoubira population located in the Pantanal were cytogenetically evaluated. Among the individuals analyzed, 9 had B chromosomes and 5 carried a heterozygous centric fusion (2n = 69 and FN = 70). In 3 individuals, the fusion occurred between chromosomes X and 16, in 1 individual between chromosomes 7 and 21, and in another individual between chromosomes 4 and 16. These striking polymorphisms could be explained by several hypotheses. One is that the chromosome rearrangements in this species are recent and not fixed in the population yet, and another hypothesis is that they represent a balanced polymorphism and that heterozygotes have an adaptive advantage. On the other hand, these polymorphisms may negatively influence fertility and raise questions about sustainability or reproductive isolation of the population.