Comparação cariotípica entre Mazama gouazoubira e Mazama nemorivaga (Artiodactyla; Cervidae) por meio de marcadores citogenéticos clássicos, fish telomérica e pintura cromossômica
Data
2012-10-30
Autores
Resende, Juliana Pinho de Almeida [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
As espécies Mazama gouazoubira e Mazama nemorivaga, por muito tempo trouxeram dúvidas quanto à sua classificação e atualmente são descritas como espécies diferentes. A constituição cariotípica de M. gouazoubira (2n=70 e NF=70) é similar à de M. nemorivaga (2n=67 a 69 e NF=69 a 72), o que as difere são o número de cromossomos B e o cromossomo X. O objetivo deste trabalho foi analisar as diferenças cariotípicas, identificando os rearranjos cromossômicos que diferenciaram as espécies. Amostras de sangue e pele foram coletadas de 23 animais (15 M. gouazoubira e 08 M. nemorivaga) e as preparações cromossômicas foram submetidas aos bandamentos (C, G e coloração Ag-RON) e a hibridização in situ fluorescente. Dos 15 M. gouazoubira 02 foram variantes e dos 8 M. nemorivaga 4 foram variantes. A banda C mostrou que nas duas espécies as regiões centroméricas e pericentroméricas de todos os cromossomos são heterocromáticas, exceto o Y que é eucromático. As regiões organizadoras do nucléolo ativas foram localizadas nos mesmos pares cromossômicos (1 e 2) nas duas espécies. Sinais teloméricos foram localizados nas extremidades de todos os cromossomos e na região mediana do X nas duas espécies foi detectado um sinal telomérico intersticial. Os machos M. nemorivaga apresentaram um cromossomo sem par homólogo a metade distal do braço q do cromossomo X. A pintura cromossômica mostrou total homeologia da sonda do cromossomo X de M. gouazoubira com o braço p e com a metade proximal do braço q do X de M. nemorivaga. A metade distal do cromossomo X não apresentou sinal de hibridização e foi originada por uma fusão em tandem de um autossomo acrocêntrico, diferenciando o sistema sexual de M. nemorivaga
The taxonomic classification of Mazama gouazoubira and Mazama nemorivaga has been uncertain, but nowadays they are described as distinct species. The standard karyotype constitution of M. gouazoubira (2n=70 and FN=70) is similar to M. nemorivaga (2n=68 and FN=70) and the differences between them are the number of B chromosomes and the morphology of X chromosome. This study aimed to analyze the karyotypic differences between M. gouazoubira and M. nemorivaga species identifying the chromosomal rearrangements that distinguished them. Blood and skin samples were collected from 23 animals (15 M. gouazoubira and 08 M. nemorivaga) and chromosomal preparations were submitted to G and C banding, Ag-NOR staining and to fluorescent hybridization in situ. From 15 M. gouazoubira analyzed here, two of them showed variants karyotypes while from eight M. nemorivaga, 4 of them were variants. The analysis of C-bands showed all centromeric and pericetromeric regions were heterochromatic, except the Y chromosome. In both species the actives nucleolar organizer regions were observed in the terminal position of chromosome pairs 1 and 2. The telomeric sites were located at all the chromosomes ends and at the half of X-chromosome q arm in both species. The males of M. nemorivaga showed one acrocentric chromosome without its corresponding pair, but it was homologous to distal half of q arm of X-chromosome. The chromosome painting analysis showed total homeology of the X-chromosome M. gouazoubira probe with the whole p arm and proximal half of q arm of X-chromosome from M. nemorivaga. The distal half of X-chromosome did not show hybridization signal and it was originated by tandem fusion of a small acrocentric, resulting in a different sexual system for M. nemorivaga
The taxonomic classification of Mazama gouazoubira and Mazama nemorivaga has been uncertain, but nowadays they are described as distinct species. The standard karyotype constitution of M. gouazoubira (2n=70 and FN=70) is similar to M. nemorivaga (2n=68 and FN=70) and the differences between them are the number of B chromosomes and the morphology of X chromosome. This study aimed to analyze the karyotypic differences between M. gouazoubira and M. nemorivaga species identifying the chromosomal rearrangements that distinguished them. Blood and skin samples were collected from 23 animals (15 M. gouazoubira and 08 M. nemorivaga) and chromosomal preparations were submitted to G and C banding, Ag-NOR staining and to fluorescent hybridization in situ. From 15 M. gouazoubira analyzed here, two of them showed variants karyotypes while from eight M. nemorivaga, 4 of them were variants. The analysis of C-bands showed all centromeric and pericetromeric regions were heterochromatic, except the Y chromosome. In both species the actives nucleolar organizer regions were observed in the terminal position of chromosome pairs 1 and 2. The telomeric sites were located at all the chromosomes ends and at the half of X-chromosome q arm in both species. The males of M. nemorivaga showed one acrocentric chromosome without its corresponding pair, but it was homologous to distal half of q arm of X-chromosome. The chromosome painting analysis showed total homeology of the X-chromosome M. gouazoubira probe with the whole p arm and proximal half of q arm of X-chromosome from M. nemorivaga. The distal half of X-chromosome did not show hybridization signal and it was originated by tandem fusion of a small acrocentric, resulting in a different sexual system for M. nemorivaga
Descrição
Palavras-chave
Veado, Cervídeo, Cariotipos, Cromossomos, Citogenética animal, Animal genetics
Como citar
RESENDE, Juliana Pinho de Almeida. Comparação cariotípica entre Mazama gouazoubira e Mazama nemorivaga (Artiodactyla; Cervidae) por meio de marcadores citogenéticos clássicos, fish telomérica e pintura cromossômica. 2012. 53 p. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, 2012.