Synaptic behaviour and morphological modifications of the X and Y chromosomes during pachytene in three species of Ctenomys (Rodentia, Caviomorpha, Ctenomyidae).
Genome
; 45(6): 1110-5, 2002 Dec.
Article
em En
| MEDLINE
| ID: mdl-12502256
Synaptic behaviour and the progression of morphological differentiation of the XY chromosome pair during pachytene was studied for the first time in three species of the South American subterranean rodents of the genus Ctenomys (tuco-tucos). In general, synapsis progression in the sex pair could be subdivided into four substages: (i) initial partial synapsis of the X and Y chromosome axes and beginning of the differentiation of the unsynapsed regions; (ii) complete or almost complete synapsis of the Y axis accompanied with morphological differentiation of the unsynapsed region of the X chromosome; (iii) a novel stage exclusive to Ctenomys perrensi consisting in a retraction of the free X axis, associated with the formation of a homogeneous and dense structure along the synaptic region, which leads to the achievement of full synapsis between sex chromosomes; or (iv) an increase in morphological complexity involving extreme splitting of the XY pair. The implications of the peculiar synaptic behaviour displayed by sex chromosomes in C. perrensi, a species complex highly polymorphic for Robertsonian translocations, are discussed in relation to both the triggering of the pachytene checkpoint and the avoidance of non-homologous associations between sex chromosomes and the asynaptic pericentromeric regions of trivalents in translocation heterozygotes.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Roedores
/
Cromossomo X
/
Cromossomo Y
/
Pareamento Cromossômico
Limite:
Animals
Idioma:
En
Revista:
Genome
Assunto da revista:
GENETICA
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Canadá