Independent fusions and recent origins of sex chromosomes in the evolution and diversification of glass knife fishes (Eigenmannia)
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
20/10/2012
20/10/2012
2011
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Resumo |
The genus Eigenmannia comprises several species groups that display a surprising variety of diploid chromosome numbers and sex-determining systems. In this study, hypotheses regarding phylogenetic relationships and karyotype evolution were investigated using a combination of molecular and cytogenetic methods. Phylogenetic relationships were analyzed for 11 cytotypes based on sequences from five mitochondrial DNA regions. Parsimony-based character mapping of sex chromosomes confirms previous suggestions of multiple origins of sex chromosomes. Molecular cytogenetic analyses involved chromosome painting using probes derived from whole sex chromosomes from two taxa that were hybridized to metaphases of their respective sister cytotypes. These analyses showed that a multiple XY system evolved recently (<7 mya) by fusion. Furthermore, one of the chromosomes that fused to form the neo-Y chromosome is fused independently to another chromosome in the sister cytotype. This may constitute an efficient post-mating barrier and might imply a direct function of sex chromosomes in the speciation processes in Eigenmannia. The other chromosomal sex-determination system investigated is shown to have differentiated by an accumulation of heterochromatin on the X chromosome. This has occurred in the past 0.6 my, and is the most recent chromosomal sex-determining system described to date. These results show that the evolution of sex-determining systems can proceed very rapidly. Heredity (2011) 106, 391-400; doi:10.1038/hdy.2010.82; published online 23 June 2010 State of Sao Paulo Research Foundation (FAPESP)[02/09717-0] Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) State of Sao Paulo Research Foundation (FAPESP)[05/51629] Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) National Council for Research and Development (CNPq) German Academic Exchange Program (DAAD) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Brazilian National Counsel of Scientific and Technologic Development (CNPq)/German Academic Exchange Program (DAAD) Deutsche Forschungsgemeinschaf (DFG) Deutsche Forschungsgemeinschaft (DFG) |
Identificador |
HEREDITY, v.106, n.2, p.391-400, 2011 0018-067X http://producao.usp.br/handle/BDPI/27483 10.1038/hdy.2010.82 |
Idioma(s) |
eng |
Publicador |
NATURE PUBLISHING GROUP |
Relação |
Heredity |
Direitos |
restrictedAccess Copyright NATURE PUBLISHING GROUP |
Palavras-Chave | #cross-species chromosome painting #mtDNA #divergence times #Gymnotiformes #partitioned Bayesian analysis #MUS-MUSCULUS-DOMESTICUS #MITOCHONDRIAL GENOME #Y-CHROMOSOME #RATES #GENE #DIFFERENTIATION #REARRANGEMENTS #GYMNOTIFORMES #TELEOSTEI #MEDAKA #Ecology #Evolutionary Biology #Genetics & Heredity |
Tipo |
article original article publishedVersion |