“…Germinal vesicle (GV) transfer techniques have represented useful tools for studying the interaction between the nucleus and the cytoplasm in the oocyte maturation process in mammals (Chiang et al, 2012;Cohen et al, 1997;Dekel and Beers, 1978;Fulka et al, 1998Fulka et al, , 2001Heacox and Schroeder, 1981;Levron et al, 1996;Li et al, 2001;Liu et al, 1999Liu et al, , 2000Zhang et al, 1999). Furthermore, GV transfer between different mammalian species has demonstrated that cytoplasmic factors regulating the progression of the first and the second meioses are not species-specific in mammalian oocytes and that these factors are located in the meiotic apparatus and/or its surrounding cytoplasm at the MII stage (Li et al, 2001).…”