DEVELOPMENTAL CAPACITY OF IN-VITRO MATURED AND FERTILIZED OOCYTES FROM PREPUBERTAL AND ADULT GOATS

The developmental competence of oocytes from prepubertal and adult goa ts was studied through in vitro maturation, fertilization and embryo c ulture up to the blastocyst stage. Oocytes were recovered from antral follicles of prepubertal and adult goat ovaries, with or without ovari an stimulation with exogenous FSH. The effect of different sources of granulosa cells during IVM on the developmental competence of prepuber tal goat oocytes was also noted. Oocytes were matured for 27 h at 38.5 degrees C in 5% CO2 in air in 50-mu l microdrops in TCM199 supplement ed with 20% estrus goat serum, FSH LH and estradiol-17 beta or in 2 ml of the same medium supplemented with granulosa cells. Matured oocytes were inseminated with freshly ejaculated spermatozoa following capaci tation At 24 h postinsemination, the oocytes were transferred to a gra nulosa cell monolayer, and early embryo development was evaluated unti l Day 10. Results show that the developmental ability of embryos from prepubertal goats after IVM and IVF is similar to those from adult goa ts. Treatment of the prepubertal and adult goats with FSH did not impr ove the developmental capacity of the resulting embryos. On studying t he addition of different sources of granulosa cells to a maturation sy stem of 2 mi of medium, a significantly positive effect of the cells f rom primed females was observed on the percentage of maturation, on em bryo cleavage and on the percentage of embryos that overcame the in vi tro developmental block from 8 to 16 cells. (C) 1997 by Elsevier Scien ce Inc.