In vitro studies of meiosis in developing goat oocytes
1996
Rajikin, M.H. (Kebangsaan Malaysia Univ., Kuala Lumpur (Malaysia). Medical Faculty. Dept. of Physiology)
The aim of this was to investigate the process of meiosis in goat oocyte cultured in vitro. A total of 836 oocytes, comprising 675 cumulus-oocyte complexes (COCs) and 161 cumulus-free oocytes (CFOs) were incubated in microdroplets of TCM 199 medium at 39 degree C in 5 percent CO2 in air for 0, 20 to 30 and 40 to 48 hr. The states during the nuclear maturation process were determined based on chromosomal configuration changes as germinal vesicle breakdown (GVBD), leptotene, zygotene, pachtene, diplotene, diakinesis, metaphase I (MI) and metaphase II (MII). At 0 hr, most of the oocytes remained at prophase, with the majority at pachytene for both COCs and CFOs. At 20 to 30 hr, 55.1 percent COCs attained MII, compared to only 20 percent CFOs (P less than 0.05); the majority of CFOs (40.0 percent) remained in the GVBD state. At 40 to 48 hr, 58.5 percent COCs and 57.6 percent CFOs developed into MII. There was a significant increase (P less than 0.001) in matured COCs at 20 to 30 hr compared to 0 hr interval, however, the difference among CFOs for the same incubation times was not significant. Between 20 to 30 and 40 to 48 hr, CFOs continually underwent maturation (P less than 0.001) whereas the percentage of COCs reaching MII was not different between the two periods of incubation. The present study indicated that the highest percentage of MII stage attained among CCOs was between 20 to 30 hr incubation in vitro
显示更多 [+] 显示较少 [-]