Improving in vitro maturation and cleavage rates of buffalo oocytes

Ano: 2009 | Volume: 6 | Número: 2

Autores: A.O. Hegab, A.E. Montasser, A.M. Hammam, E.M.A. Abu El-Naga, S.M. Zaabel

Palavras-chave: buffalo, cleavage, ivf, ivm, oocytes

Resumo Inglês:

The aim of the present study was to improve in
vitro maturation and cleavage rates of buffalo oocytes.
Good quality oocytes were divided into two
experiments. In Experiment 1 oocytes were cultured for
24 h in a CO2 incubator at 38.5oC either in TCM-199,
Ham’s F-10, MEM or FertiCult medium supplemented
with either 10% FCS or 0.3% BSA. Experiment 2 was
carried out to investigate the effect of different hormones
(either 50 μg/ml eCG, 50 μg/ml FSH or 1 mg/ml E2)
added to four of the afore mentioned media enriched
with 10% FCS at the same culture conditions. Matured
oocytes were fertilized in vitro using frozen thawed
semen capacitated with heparin and caffeine. The
sperm-oocytes were co-cultured for 22 h in BO or
TALP medium. The fertilized oocytes were cultured in
either BO or TALP medium for an additional five days
at the same culture conditions and checked daily for
cleavage. Addition of FCS to all media led to a higher
maturation rate, without any significant variation,
than BSA did (75.6 vs. 71.3%). Although no
influence on the maturation rate was observed,
addition of eCG to TCM-199, Ham’s F-10 or MEM
media resulted in a non-significant increase of in vitro
maturation rate of buffalo oocytes compared to other
hormonal additives to the same media. Furthermore,
supplementation of maturation media with eCG resulted
in a non-significant higher in vitro maturation rate of
buffalo oocytes compared to FSH and E2 (80.4% for
eCG supplemented media vs. 74.0% and 73.0% for FSH
and E2, respectively). There was a non-significant
difference in the cleavage rate of buffalo oocytes
matured in TCM-199 supplemented with either sera or
hormones and fertilized either in BO or TALP medium.
However, the highest non-significant cleavage rate was
achieved when oocytes were matured in TCM-199
supplemented with eCG and fertilized in TALP medium
(50%). The overall cleavage rate was not significantly
greater in TALP than in BO medium (33.7 vs. 15.5%).
It could be concluded that supplementation of
maturation media with FCS and/or eCG could
successfully improve IVM rate of buffalo oocytes.
Furthermore, high cleavage rate could be achieved when
oocytes were matured in TCM-199 supplemented with
FCS and eCG and fertilized in TALP medium.