Effect of medium-199 and fetal calf serum on in vitro maturation of domestic cat oocytes

In vitro maturation (IVM) and fertilization are potentially useful for propagating threatened or endangered species. The domestic cat is currently used in this field as an experimental model for studies aimed at non-domestic Felidae. At present optimal conditions for obtaining IVM of cat oocytes have not yet been completely defined. The aim of this study was to evaluate two parameters derived from the procedures that currently ensure high maturation rates in domestic ruminants: (1) the suitability of a complex medium (M-199) for IVM of cat oocytes; (2) the effect of different concentrations of fetal calf serum in the culture medium with or without the addition of gonadotrophins. The maturation rate at two different intervals from the onset of culture (24 and 48 h) was also evaluated. The use of M-199 allowed resumption of meiosis in 4.3-18.7% of cat oocytes, according to the supplements and culture periods used. No significant differences were recorded among the treatment groups (P > 0.05). Meiosis was completed in 90.9% of cases within 24 h with no significant differences between the three treatment groups (P > 0.05). A 3.2% rate of parthenogenesis was observed at the end of the maturation period with no significant differences between the culture systems (P > 0.05). However, the percentage cleavage of oocytes was much higher (29%) when correlated with the percentage that had matured. In this case significant differences among treatments were also observed (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)