The results showed that Nodal was mainly distributed in granulosa cells close to the follicle cavity.

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.

Study on in vitro maturation of bovine oocytes derived from antral follicles;

Comparison in dynamic patterns of ovarian antral follicles between natural and superovulated estrous rats;

Study on Maturation and Fertilization in Vitro of Bovine Oocytes Derived from Antral Follicles;

The hircine nonantral follicle oocytes were proved in the present experiment to survive and grow in DMEM supplemented with HEPES (20 mmol/L), FCS(10%), FSH(40 mg/L), hypoxanthine (2 mmol/L), dbcAMP(2 mmol/L), IGF1(50 g/L), hydrocortisone(40 g/L) and ITS(50 g/L).