Influence of stages anestrous and diestrus in chromatin configuration in germinal vesicle of canine oocytes

In canine specie, oocyte maturation rates are low and the percentage of oocytes that remain in the stage of germinal vesicle (GV) regardless of culture conditions is high. During maturation oocyte undergoes modification and the GV chromatin remodeling manifested by changes in the configuration and p...

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Detalhes bibliográficos
Autores: Pereira, Leda Maria Costa, Bersano, Paulo Ricardo de Oliveira, Lopes, Maria Denise
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:Brasil
Recursos:Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo (FMVZ-USP)
Repositorio:Brazilian Journal of Veterinary Research and Animal Science
Idioma:portugués
OAI Identifier:oai:revistas.usp.br:article/55590
Acesso em linha:https://www.revistas.usp.br/bjvras/article/view/55590
Access Level:acceso abierto
Palavra-chave:Oócito
Cromatina
Vesícula germinativa
Cadelas
Oocyte
Chromatin
Germinal vesicle
Bitches
Descrição
Resumo:In canine specie, oocyte maturation rates are low and the percentage of oocytes that remain in the stage of germinal vesicle (GV) regardless of culture conditions is high. During maturation oocyte undergoes modification and the GV chromatin remodeling manifested by changes in the configuration and positioning. The objective of this work is to evaluate the configuration and positioning of chromatin of oocytes in GV stage during anestrus and diestrus bitches. The ovaries of 33 females (20 bitches in anestrous and 13 in diestrus) were isolated, sliced and only cumulus-oocyte complexes (COCs) grade 1 were subjected to solution of 0.2% hyaluronidase for release in cumulus cells. After this process, the selected oocytes were stained and evaluated. From a total of 920 oocytes, 566 were classified as grade 1 and the stages of chromatin configuration identified as GV-1, GV-2, GV-3 and GV-4. The observed changes in chromatin configuration been characterized as a transition dispersed chromatin (GV-1, GV-2) for partially condensed (GV-3) until it reaches a fully condensed stage (GV-4). The data analyzed from the chromatin configuration showed a significant difference between the stages with a higher proportion of GV-1 and GV-2 for the anoestrus and GV-3 and GV-4 during diestrus. There is need for further studies to be able to have a proper understanding of the influence of chromatin configuration of oocytes in GV stage in resumption of meiosis and consequently in oocyte meiotic competence.