Data/hora: 21/09/2024 18:11:58

Biblioteca(s): 	Embrapa Caprinos e Ovinos.	
Data corrente: 	09/01/2013	
Data da última atualização: 	13/07/2016	
Autoria: 	FIGUEIREDO, J. R. de; CELESTINO, J. J. de H.; FAUSTINO, L R.	
Título: 	Advances in artificial ovary in goats.	
Ano de publicação: 	2010	
Fonte/Imprenta: 	Acta Scientiae Veterinariae, Porto Alegre, v. 38, p. s417-424, 2010. Suplemento 2. Edição dos anais da 24. Reunião Anual da Sociedade Brasileira de Tecnologia de Embriões, Porto de Galinhas, PE, 2010.	
Idioma: 	Inglês	
Conteúdo: 	Background: In livestock including goats, the modern assisted reproductive technologies are being used for the improvement and preservation of livestock genetics and the enhancement of reproductive efficiency. It is well known that mammalian ovaries contain many thousands of immature oocytes enclosed predominantly in preantral follicles (PF). However, more than 99.9% of follicles will not ovulate but instead they will be eliminated by a physiological process called atresia. The rescue of PF from the ovaries follow by the development of in vitro culture systems (artificial ovary) which allow the in vitro growth and maturation (IVGM) of their enclosed immature oocytes up to maturation stage by preventing follicular atresia could have a major impact on the in vitro embryo production in the future. In vitro studies have demonstrated satisfactory results with laboratory animals. The birth of a mouse from primordial follicles grown, matured and fertilized in vitro was obtained. Despite the good results in mice, in other animals, including livestock, at most a few embryos have been produced from IVGM oocytes from in vitro grown oocytes.

Review: The in vitro culture of preantral follicle, also called artificial ovary, is an important step of the Manipulation of Oocytes Enclosed in Preantral Follicles (MOEPF). It aims to create in vitro an appropriated culture system which allows the survival, grow, maturation and further fertilization of small oocytes from preantral follicles, by preventing the follicular atresia that occurs abundantly in the ovaries. This article emphasizes the different steps of the MOEPF, its importance and finally, the main results obtained by our research team related to the in vitro culture of caprine preantral follicles. Our group has developed research with PF including isolation, conservation (cooling and cryopreservation) and in vitro culture of PF, focus on caprine species. In our laboratory, it was established efficient protocols for the isolation and conservation of PF, being the in vitro culture of PF up to maturation stages the major limitation at present. The types of in vitro culture systems available for preantral follicles include the culture of whole ovary, ovarian cortical slices and mechanically and/or enzimatically isolated follicles. We have been tested the effects of several substances including coconut water solution, antioxidants, serum, different types of hormones and growth factors on in vitro culture of preantral follicles enclosed in ovarian fragments. The early work of our group with culture of isolated secondary follicles were conducted involving the basic conditions of culture, i.e., ideal oxygen tension, regime of medium change, and how to culture the isolated follicles, individual or group, with or without FSH, in the presence or absence of antral follicles. The basic culture system for the in vitro culture of caprine PF which maintains follicular survival is well established. Primordial follicle activation and their further growth up to secondary stage in vitro were achieved. Isolated primary follicles can growth up to antral stage although this rate is still low. Antrum formation and fully grown oocytes were obtained from in vitro culture of large secondary follicles even yielding a few mature oocytes and embryos. Conclusion: In vitro embryo production from caprine preantral follicles grown in vitro was successfully achieved by our research group. At present, the key challenge for researchers in this important field of reproduction is to increase the rates of maturation and in vitro production of embryos from oocytes	
Palavras-Chave: 	Folículos pré-antrais; MOIFOPA.	
Thesagro: 	Caprino; Cultura In Vitro; Ovário; Ovino; Reprodução Animal.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Caprinos e Ovinos (CNPC)