The ultrastructural characteristics of the bovine preantral follicles isolated freshly;

Isolation and culture of preantral follicles from buffalo fetal, heifer and adult cow ovaries;

Progress in the research on preantral follicles of animals;

The Study on the distributing and histomorphology of buffalo preantral follicles;

Study on the isolation of buffalo and mouse preantral follicles;

Effect of nerve growth factor on in vitro development of bovine preantral follicle;

This article introduces the research in advance in vitro maturation of mammal oocytes derived from small antral follicles,and analysed the factors which influenced in vitro maturation of small antral follicular oocytes such as pick-up methods,culture period,serum,hormones and so on.

Intact goat small antral follicles were dissected from ovaries by a microsurgical method and cultured individually in 24—well tissue culture plate.

Goat ovaries were collected at breediiig and nonbreeding seasons，The oocytes derived from large（LAF，3-6mm）and small antral follicles（SAF，＜2 mm）were recovered and used for matturation and fertilization in vitro, The results are as follows：①in vitro maturation rate of LAF and SAF oocytes is significantly higher at breeding seasons(68．4％，27.

5μg/mL transferring, 100ng/mL insulin and 4ng/mL selenium for culture of bovine preantral follicles were developed Under conditions of 250μl McCoy s 5a culture medium in each well of 96-well cuture plates and one follicle in each well, the effects of NGF on in Vitro Development of Preantral Follicles were studied, The results showed that different concentrations of NGF.

Studies on the IVM and IVF of Small Antral Follicular Oocytes in Nanyang Cattle;