Rat Oocyte Maturation: Effects of Protein Synthesis Inhibitors

Calcium and meiotic maturation of the mammalian oocyte

“…Spontaneous GVBD in rodent oocytes will occur within 2-4 hr of follicular release (mouse, Donahue, 1968;rat, Dekel and Beers, 1978;Ekholm and Magnusson, 1979;hamster, Racowsky, 19861, whereas sheep and cow oocytes will not undergo GVBD until 6-9 hr later (sheep, Moor and Crosby, 1986;cow, Motlik et al, 1978;Suss et al, 1988;Homa, 1988;Sirard et al, 1989). Pig oocytes require between 12 and 16 hr of culture before the majority of oocytes undergo GVBD (Motlik and Fulka, 1976;McGaughey and Van Blerkom, 1977;Kaufman and Homa, 1993) and in the human, it may take up to 25 hr culture until GVBD is observed (Edwards, 1965b;Zamboni et al, 1972;Suzuki et al, 1981;Homa and Kaufman, unpub.…”

Mammalian oocyte maturation

“…This is the case when meiosis resumes very rapidly as in rodent oocytes. In fact, Ekholm and Magnusson (1979) (Golbus and Stein, 1976). Moroever Clarke andMasui (1983, 1985) demonstrate that the block at metaphase II also needs active protein synthesis, whereas in presence of puromycine, M I (Clarke and Masui, 1986 Cortical and perinuclear distribution also of the Golgi elements varies during the maturation processes.…”

Effect of cycloheximide upon maturation of bovine oocytes

“…This means that cattle oocytes belong to the group of mammals in which GVBD is protein synthesis-dependent (pig; Fulka Jr. et al, 1986; sheep : Moor & Crosby, 1986). As has been shown in the rat GVBD inhibition is possible only after previous preincubation of these oocytes in dbcAMP + cycloheximide-supplemented medium and subsequent culture in the presence of protein synthesis inhibitor (Ekholm & Magnusson, 1979 (Fulka Jr., unpublished results). It is clear that the mouse is the only mammalian species of all those species studied so far shown to be independent of protein synthesis for GVBD.…”

“…In the rat, GVBD occurs in the presence of cycloheximide; however, when these oocytes are cultured in dbcAMP and cycloheximide-supplemented medium and thereafter in only cycloheximide-supplemented medium, the process of GVBD is significantly reduced (Ekholm & Magnusson, 1979). These results indicate the existence of short-lived proteins necessary for meiosis resumption.…”