Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from Brazil
The karyotypes of 85 specimens of Oligoryzomys nigripes (Rodentia, Sigmodontinae) collected in the Cerrado and Atlantic Forest of seven states of Brazil were analyzed. Eighty four specimens presented a karyotype with 2n = 62 and one individual had 2n = 61 due to a monosomy of the X chromosome. High...
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Sociedade Brasileira de Genética
2007-01-01
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doaj-6a5f070f60e74a7e92413eb8d01b5ec52020-11-25T01:25:20ZengSociedade Brasileira de GenéticaGenetics and Molecular Biology1415-47571678-46852007-01-01301435310.1590/S1415-47572007000100010Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from BrazilRoberta ParesqueMaria José de Jesus SilvaYatiyo Yonenaga-YassudaValéria FagundesThe karyotypes of 85 specimens of Oligoryzomys nigripes (Rodentia, Sigmodontinae) collected in the Cerrado and Atlantic Forest of seven states of Brazil were analyzed. Eighty four specimens presented a karyotype with 2n = 62 and one individual had 2n = 61 due to a monosomy of the X chromosome. High levels of intra- and inter-population karyotypic variability, due to sex chromosomes heteromorphisms and pericentric inversions in four autosomes (pairs 2, 3, 4 and 8), led to a variation of the autosomal arm numbers (fundamental number, FN) from 78 to 82. Synaptonemal complex analyses revealed normal meiosis in males heterozygous for pericentric inversions. We found 39 different cytotypes, 27 of which are herein described for the first time. A literature survey revealed 46 described karyotypes for O. nigripes. We tested the hypothesis that chromosomal variants frequencies are dependent on geographical distribution and we propose a model for the karyotypical evolution of Oligoryzomys nigripes with 2n = 62/FN = 78-82.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100010pericentric inversionOryzomyiniOligoryzomys nigripesRodentiaclinal variation |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Roberta Paresque Maria José de Jesus Silva Yatiyo Yonenaga-Yassuda Valéria Fagundes |
spellingShingle |
Roberta Paresque Maria José de Jesus Silva Yatiyo Yonenaga-Yassuda Valéria Fagundes Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from Brazil Genetics and Molecular Biology pericentric inversion Oryzomyini Oligoryzomys nigripes Rodentia clinal variation |
author_facet |
Roberta Paresque Maria José de Jesus Silva Yatiyo Yonenaga-Yassuda Valéria Fagundes |
author_sort |
Roberta Paresque |
title |
Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from Brazil |
title_short |
Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from Brazil |
title_full |
Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from Brazil |
title_fullStr |
Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from Brazil |
title_full_unstemmed |
Karyological geographic variation of Oligoryzomys nigripes Olfers, 1818 (Rodentia, Cricetidae) from Brazil |
title_sort |
karyological geographic variation of oligoryzomys nigripes olfers, 1818 (rodentia, cricetidae) from brazil |
publisher |
Sociedade Brasileira de Genética |
series |
Genetics and Molecular Biology |
issn |
1415-4757 1678-4685 |
publishDate |
2007-01-01 |
description |
The karyotypes of 85 specimens of Oligoryzomys nigripes (Rodentia, Sigmodontinae) collected in the Cerrado and Atlantic Forest of seven states of Brazil were analyzed. Eighty four specimens presented a karyotype with 2n = 62 and one individual had 2n = 61 due to a monosomy of the X chromosome. High levels of intra- and inter-population karyotypic variability, due to sex chromosomes heteromorphisms and pericentric inversions in four autosomes (pairs 2, 3, 4 and 8), led to a variation of the autosomal arm numbers (fundamental number, FN) from 78 to 82. Synaptonemal complex analyses revealed normal meiosis in males heterozygous for pericentric inversions. We found 39 different cytotypes, 27 of which are herein described for the first time. A literature survey revealed 46 described karyotypes for O. nigripes. We tested the hypothesis that chromosomal variants frequencies are dependent on geographical distribution and we propose a model for the karyotypical evolution of Oligoryzomys nigripes with 2n = 62/FN = 78-82. |
topic |
pericentric inversion Oryzomyini Oligoryzomys nigripes Rodentia clinal variation |
url |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000100010 |
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