Growth of anuran oocytes in serum-supplemented medium
Reproduction nutrition development (Print)
Appropriately-sized oocytes from Xenopus laevis can be grown in vitro in vitellogenin-containing serum for up to 2 weeks. The source of serum appears to be unimportant. Rates of oocyte growth are somewhat better than those achieved in the presence of vitellogenin alone. Rana pipiens oocytes grow about twice as fast as X. laevis oocytes under identical conditions. The oocyte culture conditions described appear to be applicable to amphibian oocytes in general. Introduction. We have recently
... have recently described the growth and differentiation of Xenopus laevis oocytes in a defined medium . The essential features of our procedure included (1) manual dissection of oocytes from their outer follicular layers, and (2) incubation of the isolated oocytes in an appropriate nutrient medium containing vitellogenin, the macromolecular precursor to yolk proteins. No serum supplement was used, since we found in our initial explorations that it did not seem to be particularly beneficial . One of the prerequisites for oocyte culture, therefore, was the isolation of vitellogenin from the blood of X. laevis. Large-scale isolation and purification of vitellogenin may prove difficult or inconvenient for some who lack the appropriate facilities. Furthermore, most workers will probably not require a defined medium for the purpose of their research. We have, therefore, re-explored the use of vitellogenin-containing serum as a simplified procedure for culturing the oocytes of X. laevis and those of a distantly related anuran, Rana pipiens. We document here some of our findings, including the optimum conditions for oocyte growth. Materials and methods. Animals and chemicals. -X. laevis males and females were obtained from South Africa (South African Snake Farm, Fish Hœk, Cape Province), and R. pipiens females were purchased from the Amphibian Facility (University of Michigan, Ann Arbor, Mi).