Effect of bone morphogenetic protein-7 (BMP-7) on in vitro survival of caprine preantral follicles

Abstract

305Pesq. Vet. Bras. 30(4):305-310, abril 2010 RESUMO.-[Efeito da Proteína Morfogenética Óssea 7 (BMP-7) para a sobrevivência in vitro de folículos pré-antrais caprinos.] O presente trabalho foi conduzido de modo a se verificar o efeito de diferentes concentrações da BMP-7 no desenvolvimento in vitro de folículos pré-antrais caprinos. Fragmentos de tecido cortical ovariano caprino foram cultivados por 1 ou 7 dias em Minimum Essential Medium (MEM + ) suplementado com diferentes concentrações de BMP-7 (1, 10, 50 ou 100ng/ml). Os fragmentos não cultivados ou aqueles cultivados por 1 ou 7 dias foram processados para histologia clássica e microscopia eletrô-nica de transmissão (TEM), sendo avaliados parâmetros morfológicos indicativos de viabilidade, ativação e crescimento. Os resultados mostraram que o percentual de folículos morfologicamente normais diminuiu significativamente em todos os tratamentos quando comparados ao controle, exceto na concentração de 1ng/ml por 1 dia de cultivo. Já no D7 todos os tratamentos reduziram significativamente os percentuais de folículos morfologicamente normais. Utilizando 10ng/ml de BMP-7 foi observado um ) supplemented with different concentrations of BMP-7 (1, 10, 50 or 100ng/ml). Noncultured fragments or those cultured for 1 or 7 days were processed for classical histology and transmission electron microscopy (TEM). Parameters such as follicular survival, activation and growth were evaluated. The results showed that, after 1 or 7 days of culture, the percentage of morphologically normal follicles was significantly reduced in all treatments when compared with fresh control, except at 1ng/ml of BMP-7 for 1 day. In addition, the concentration of 10ng/ml of BMP-7 significantly increases follicular diameter from day 1 to 7 of culture. There was no influence of the other concentrations of BMP-7 regarding to the follicular and oocyte diameter. Ultrastructure studies confirmed follicular integrity after 7 days of culture in 1ng/ml BMP-7. In conclusion, small concentrations of BMP-7 can improve the survival and growth of caprine preantral follicles during in vitro culture.INDEX TERMS: Ovary, preantral follicles, growth factor, bone morphogenetic protein-7, BMP-7, goats.Pesq. Vet. Bras. 30(4):305-310, abril 2010 Valdevane R. Araújo et al. 306 aumento significativo no diâmetro folicular quando comparados os diferentes períodos de cultivo. Não houve influên-cia das demais concentrações de BMP-7 quando avaliados além do diâmetro folicular o diâmetro oocitário. A aná-lise por TEM confirmou a integridade ultra-estrutural nos folículos após 7 dias de cultivo com 1ng/ml de BMP-7 . Em conclusão, o BMP-7 em baixas concentrações pode melhorar a sobrevivência e o crescimento durante o cultivo in vitro de folículos pré-antrais caprinos.TERMOS DE INDEXAÇÃO: Ovário, folículos pré-antrais, fator de crescimento, proteína morfogenética óssea 7, BMP-7, caprinos.

First characterization of preantral follicles in the ovaries of adult alpaca

“…The proportions of primordial, transitional, primary and secondary follicles were determined in the present study. Interestingly, the percentages of primordial (71.23%) and transitional follicles in alpaca were similar to those reported for small ruminants (goat (6) and ewe (7)), while the proportion of the primary follicles (6.05%) corresponded to the findings in bovines (5). Also, Arias et al (8), in their analysis of ovarian samples of the llama species (Lama glama), found that most preantral follicles were in the primordial state.…”

“…Their activation and arrest stages during folliculogenesis are poorly understood (4). Considering the significance of the preantral follicles in assisted reproductive techniques, several studies have been conducted to describe their morphometric aspects in cow, goats, ewe and llamas (5)(6)(7)(8). However, to the best of our knowledge, no reports are yet available regarding the ovarian preantral follicles in the alpaca.…”

Influence of Insulin-like Growth Factor I (IGF-I) on the survival and the in vitro development of caprine preantral follicles

“…Several studies have emphasized the importance of ultrastructural analysis after the in vitro culture of preantral follicles (cow: Van Den Hurk et al 1998;mouse: Salehnia et al 2002, goat: Matos et al 2007a, Araújo et al 2010. In the present study, the cultured follicles were characterized by a large number of vacuoles, absence of organelles in the cytoplasm, as well as the nuclear envelope and the cytoplasmic membrane presenting irregularities or fragmentation.…”

“…The more the cell needs energy to perform its vital functions, it will produce more mitochondria. The addition of pyruvate (0.23mM) to the culture medium has been frequently performed in several researches, with positive results (Araújo et al 2010, Martins et al 2010. Studies have demonstrated that the activation of primordial follicles can occur "spontaneously", that is, without the addition of growth factors or hormones (Eppig & O'Brien 1996).…”

Effect of Somatotropin and Thyroxine on the in Vitro Development of Bovine Preantral Follicles

“…Ultrastructural analysis was performed in PAOF cultured for seven days (Figure 2). This evaluation was performed since some conditions presented by the follicles can only be observed at ultrastructure level, as the presence of cytoplasmic organelles, the condition of GC, the quantity of cytoplasmic vacuoles, and the integrity of cell membranes after in vitro culture (33) .…”