Recovery rate, morphological quality and nuclear maturity of canine cumulus-oocyte complexes collected from anestrous or diestrous bitches of different ages
Articolo
Data di Pubblicazione:
2007
Citazione:
Recovery rate, morphological quality and nuclear maturity of canine cumulus-oocyte complexes collected from anestrous or diestrous bitches of different ages / G. Lopes, M. Sousa, G.C. Luvoni, A. Rocha. - In: THERIOGENOLOGY. - ISSN 0093-691X. - 68:6(2007), pp. 821-825.
Abstract:
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.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Canine ; Cumulus-oocyte complexes ; Estrous cycle ; Age ; Oocyte quality
Elenco autori:
G. Lopes, M. Sousa, G.C. Luvoni, A. Rocha
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