Zygotes without cumulus cells
were washed in M16 medium containing 25mM H2O2 three times and then cultured in the same medium at 37AdegC in a humidified atmosphere of 5% CO2 in air for 30 min.
CHARACTER OF THE CUMULUS CELLS
IN OOCYTE MATURATION
COCs with oocytes surrounded by at least three layers of compact cumulus cells
and uniform cytoplasm were selected for further experiments.
have shown a methylated type of PGC1[alpha] promoter found in the leukocytes of PCOS patients, but to our knowledge no previous study has assessed transcript level of PGC1[alpha]/FNDC5 axis in cumulus cells
surrounding the oocytes.
Literature showed that lncRNA in reproductive cumulus cells
may contribute to the regulation of oocyte maturation, fertilization, and embryo development.
The culture conditions used for in vitro maturation (IVM), which include various media types and hormone supplements, as well as the presence of cumulus cells
, can significantly influence maturation rates and subsequent embryo development [14, 17-19].
In cattle, batches of miRNAs are present in the ovary (Hossain et al., 2009), and miRNAs demonstrate spatio-temporal expression in oocytes, granulosa cells (GCs), cumulus cells
, and preimplantation embryos (Abd El Naby et al., 2013).
GV oocytes with or without cumulus cells
were subjected to IVM in either ESCM, Embryonic Stem Cell Growth Medium (ESGM), or [alpha]-minimum essential medium ([alpha]-MEM).
Apoptotic index within cumulus cells
is a questionable marker of meiotic competence of bovine oocytes matured in vitro.
Interestingly, SOD3 can be translocated from cumulus cells
into oocytes under certain conditions .
Progesterone (P4) and estradiol-17beta (E2) are steroid hormones that regulate important phases of the reproductive cycle including oocyte growth and maturation and follicle development from the preantral to antral stage, as well as differentiation of follicular theca, granulosa, and cumulus cells
. Both of these steroids act via specific nuclear receptors that form specific complexes that bind to promoter response elements and regulate target gene expression.