Canine cumulus-oocyte complexes (COC) were recovered from ovaries of post-pubertal animals (1–3, 4–6 and 7–10 years old) at different ovarian estrous phases (anestrus and diestrus). The number of COCs, and the number and nuclear maturity of highquality (grade-1) oocytes were assessed. For all animals, no significant differences were found between the two reproductive phases relatively to the total number of COCs and grade-1 oocytes recovered. However, significant higher numbers of COCs were recovered from young than from elderly animals, and the proportion of grade-1 oocytes was also significantly higher in the younger group than in the other two age-groups. Of 226 grade-1 oocytes, 73% were at the germinal vesicle stage (GV), 10% had resumed meiosis (9% at germinal vesicle breakdown; 1% at metaphase-I) and 17% were degenerated. A significant effect of the reproductive phase on oocyte nuclear maturity was found only for adult animals, with a higher number of GVoocytes being found at anestrous (79%) due to higher rates of meiosis resumption (34%) at diestrous. The high number of grade-1 oocytes with meiosis resumption and fragmented or unidentified nuclear contents, indicates that current criteria for the selection of viable canine COCs are not optimized and need a new definition.
|Titolo:||Recovery rate, morphological quality and nuclear maturity of canine cumulus-oocyte complexes collected from anestrous or diestrous bitches of different ages|
LUVONI, GAIA CECILIA (Penultimo)
|Parole Chiave:||Canine ; Cumulus-oocyte complexes ; Estrous cycle ; Age ; Oocyte quality|
|Settore Scientifico Disciplinare:||Settore VET/10 - Clinica Ostetrica e Ginecologia Veterinaria|
|Data di pubblicazione:||2007|
|Digital Object Identifier (DOI):||10.1016/j.theriogenology.2007.06.011|
|Appare nelle tipologie:||01 - Articolo su periodico|