Caracterização da população de foliculos ovarianos pré-antrais de fetos bovinos e cultivo in vitro de tecido ovariano associado a proteína morfogenética óssea 9

Abstract

Increasing the efficiency of in vitro culture of preantral follicles is still a major challenge as in vivo development conditions involve several unknown factors. For this purpose, it is necessary researches aiming to improve and simplify the methodology and conditions of cell culture during the various stages of the process. Due to these reasons, this thesis is composed of three chapters, that had as main objective to evaluate the in vitro development of preantral follicles of bovine fetuses included in fragments, in culture media supplemented with bone morphogenetic protein 9 (BMP-9) at three concentrations (50, 100 and 200 ng/ml) for 7 days. The first chapter addresses general considerations regarding the topics covered in the other chapters. The second chapter aimed to characterize histologically the ovarian development of bovine fetuses, analyzing the morphological and quantitative aspects of the follicular population, to serve as reference for the experiment described in the final chapter. This proposed a culture medium to support the growth of preantral follicles of bovine fetuses. Bone morphogenetic protein 9 (BMP-9) was added to the medium and its effects on the histological characteristics and survival and in vitro viability of bovine preantral follicles were measured. We conclude that bovine fetuses from the age of four months present a population of preantral follicles formed with associated follicular activation processes, and can be used in biotechniques. It was also concluded that the addition of 50 ng/ml of BMP-9 to the culture medium exerts a beneficial effect in preserving the viability of primordial follicles, in addition to an inhibitory effect on follicular activation during the culture period.