Effects of follicular phase and oocyte-cumulus complexes quality on the protein profile and in vitro oocyte meiosis competence in Cebus apella.
OBJECTIVE
To study the protein profile of oocytes and cumulus cells from different sized follicles throughout the follicular phase and to asses the ability of oocytes to progress from the dictyate to metaphase II (MII) stage.


METHODS
Animal model study.


METHODS
Five academic basic research laboratories and the National Primate Centre.


METHODS
Eleven normal, cycling capuchin monkey (Cebus apella) females.


METHODS
Cumulus-oocyte complexes and denuded oocytes were recovered by antral follicle aspiration.


METHODS
Protein profile analysis of denuded or intact oocytes.


RESULTS
The protein profiles of 25 denuded or intact oocytes recovered on days 5 (six denuded, five intact), 7 (four denuded, four intact), or 9 (one denuded, five intact) of the menstrual cycle were analyzed; in a second experiment, 40 intact oocytes were cultured for 24 (n = 20) or 36 hours (n = 20). The oocytes were denuded, fixed, stained, and microscopically examined to reveal the meiotic stage. The protein profile in each compartment within the cumulus-oocyte complex varied along the follicular development with a predominance of low-molecular-weight proteins in both oocyte and cumulus cells at final stages. No differences were found in the protein profile among oocytes pertaining to different sized follicles that were in the same day of the follicular phase. Oocyte MII competence was achieved only after incubation for 36 hours, and the highest maturation rate occurred in those becoming from dominant follicles.


CONCLUSIONS
Our study shows, for the first time in a New World primate species, that the proteins contained in oocytes and cumulus cells reach an identical profile in the late follicular phase. This phenomenon could be related to the oocyte's ability to progress to the MII stage.
Domingues
Sheyla F S
SF
Laboratory of Wild Animal Biology, Federal University of Pará, Belém, Pará, Brazil. shfarha@ufpa.br
Caldas-Bussiere
Maria C
MC
Petretski
Marilvia D
MD
Ohashi
Otávio M
OM
Lima
Julianne S
JS
Santos
Regiane R
RR
Cordeiro
Marcela S
MS
Gomes de Castro
Paulo H
PH
D000818:Animals; D002428:Cebus; D002478:Cells, Cultured; D054885:Cumulus Cells / Q000378:metabolism*; D005260:Female; D005498:Follicular Phase / Q000378:metabolism*; D008540:Meiosis; D009865:Oocytes / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D013997:Time Factors
D011506:Proteins