In vitro culture of secondary follicles and prematuration of cumulus–oocyte complexes from antral follicles increase the levels of maturation‐related transcripts in bovine oocytes

Abstract

This study evaluates the levels of messenger RNA (mRNA) for eIF4E, PARN, H1FOO, cMOS, GDF9, and CCNB1 in oocytes from secondary and antral follicles at different stages of development. The effects of in vitro culture, in vitro prematuration, and in vitro maturation on the expression of these genes on oocytes were also analyzed. The results showed that mRNA levels for H1FOO, GDF9, and PARN were higher in oocytes from small, medium, and large antral follicles, respectively, than those seen in secondary follicles. Oocytes from small, medium, and large antral follicles had higher levels of CCNB1 than oocytes from secondary follicles. Oocytes from cultured secondary follicles had higher levels of GDF9, CMOS, PARN, eIF4E, CCNB1, and H1FOO than before culture. Prematured oocytes from small antral follicles had higher levels of mRNA for GDF9, PARN, and eIF4E than before culture. In addition, higher levels of cMOS and H1FOO were identified in prematured oocytes from medium antral follicles. In conclusion, follicular growth is associated with an increase in the expression of H1FOO, GDF9, CCNB1, and PARN. The culture of secondary follicles, prematuration, and maturation of oocytes from antral follicles increase the expression of eIF4E, PARN, H1FOO, cMOS, GDF9, and CCNB1.

Effects of oocyte-derived growth factors on the growth of porcine oocytes and oocyte–cumulus cell complexes <i>in vitro</i>

“…In the present study, the expression levels of GDF9 and BMP15 mRNAs did not change significantly during antral follicle development. In previous reports, the mRNA levels of GDF9 were higher in bovine oocytes in antral follicles than in oocytes in secondary follicles [49]. Furthermore, GDF9 and BMP15 mRNAs were expressed constantly in bovine oocytes throughout the antral follicle stage [50].…”