Transforming growth factor-β (TGF-β) maintains follicular ultrastructure and stimulates preantral follicle growth in caprine ovarian tissue cultured in vitro

O objetivo desse estudo foi investigar se o TGF-β afeta a sobrevivência, ativação e crescimento de folículos primordiais caprinos inclusos no córtex ovariano após o cultivo in vitro. Ovários de cabras foram coletados em abatedouro e fragmentos de tecido ovariano foram cultivados por um e sete dias em meio essencial mínimo alfa (α-MEM+) sozinho ou suplementado com TGF-β (1, 5, 10 ou 50ng/mL). Fragmentos ovarianos não cultivados e cultivados foram processados para análise histológica e ultraestrutural. Os resultados mostraram que, comparado ao controle fresco, houve diminuição no percentual de folículos morfologicamente normais em todos os tratamentos somente após sete dias de cultivo. O TGF-β não afetou a ativação folicular independente da concentração testada, contudo, o diâmetro folicular foi superior (P<0.05) no tratamento com 10ng/mL de TGF-β quando comparado ao controle fresco e aos demais tratamentos. Além disso, essa mesma concentração manteve a ultraestrutura normal dos folículos após sete dias de cultivo. Em conclusão, o TGF-β apresentou efeito adicional no crescimento folicular e na manutenção da integridade ultraestrutural de folículos pré-antrais caprinos inclusos no tecido ovariano quando utilizado na concentração de 10ng/mL durante sete dias de cultivo.The objectives of this study were to investigate whether TGF-β affect the survival, activation and further growth of goat primordial follicles enclosed in ovarian cortex after in vitro culture. Goat ovaries were collected from an abattoir and pieces of ovarian tissues were cultured for one or seven days in a supplemented alpha Minimum Essential Medium, alone or containing TGF-β (1, 5, 10 or 50ng/mL). Ovarian tissues from the fresh control as well as those cultured were processed for histological and ultrastructural studies. The results showed that when compared with fresh control, there was decrease in the percentages of histologically normal follicles in all treatments only after seven days culture. TGF-β did not affect the activation of preantral follicles regardless of its concentration, however, larger follicles diameter (P<0.05) was observed using 10ng/mL TGF-β than in the fresh control and other treatments. Moreover, this concentration maintained the normal ultrastructure after seven days of culture. In conclusion, TGF-β showed additional effect on the follicle growth and the maintenance of ultrastructural integrity of goat preantral follicles enclosed in ovarian tissue when used at 10ng/mL during seven days of culture

Histological and ultrastructural feature and nitrite production of caprine preantral follicles in vitro cultured in the presence or absence of serum

Avaliou-se o efeito da adição de diferentes tipos e concentrações de soro sobre o desenvolvimento e a sobrevivência de folículos ovarianos pré-antrais (FOPA) caprinos in vitro. Além disso, verificou-se a relação entre as concentrações de nitrito presentes no meio de cultivo e a viabilidade folicular. Cada par ovariano foi dividido em 29 fragmentos, sendo um destinado ao controle. Os fragmentos foram cultivados por um ou sete dias em meio essencial mínimo suplementado (MEM+) ou MEM+ com diferentes concentrações (10 ou 20%) de soro fetal bovino (SFB), soro de cabra em estro (SCE) ou soro de cabra em diestro (SCD). Na análise morfológica após sete dias, apenas o tratamento com 10% de SFB apresentou percentual de FOPA normais similar ao MEM+ (P>0,05). A análise ultra-estrutural dos folículos cultivados por sete dias com MEM+ ou MEM+ com 10% de SFB mostrou danos oocitários, porém células da granulosa normais. A análise do meio de cultivo revelou correlação positiva entre a viabilidade folicular e a produção de nitrito. A suplementação com soro não melhorou a viabilidade de FOPA e a concentração de nitrito no meio de cultivo funcionou como um indicador da viabilidade das células da granulosa de FOPA caprinos cultivados in vitro. ______________________________________________________________________________________________________________ ABSTRACTThe effect of the addition of different types and concentrations of sera on the viability and development of caprine preantal follicles (PAF) in vitro cultured was analyzed. In addition, it was evaluated the correlation between nitrite concentrations in culture medium and folicular viability. Each ovarian pair was divided in 29 fragments and one was used as control. The fragments were cultured for one or seven days in minimal essential medium (MEM+) or MEM+ with different concentrations of (10 or 20%) bovine fetal serum (BFS), estrous goat serum (EGS), or diestrous goat serum (DGS). After seven days, the morphological analysis showed that only the treatment with 10% BFS maintained the percentage of normal PAF similar to MEM+ (P>0.05). The ultrastructural analysis of follicles cultured for seven days in MEM+ or MEM+ with 10% BFS showed some oocyte damage, although the granulosa cells were normal. Analysis of culture medium revealed a positive correlation between follicular viability and nitrite production. Supplementation with serum did not improve the viability of PAF and nitrite levels in culture medium served as an indicator of viability of granulose cells from caprine PAF in vitro cultured

Bayesian analysis of lamb survival using Monte Carlo numerical integration with importance sampling

Approximate and exact Bayesian analyses of survival from birth to weaning measured as an "all or none" trait were conducted on 2,554 Rambouillet lambs using an asymptotic normal approximation and Monte Carlo numerical integration with importance sampling, respectively. A linear logistic model was used to assess the effects of year, age of dam, sex of lamb, and type of birth on the survival probability. A least squares analysis of the data, ignoring their discrete nature, was also performed. The Bayesian analyses were compared by plotting the marginal posterior distributions and by constructing 95% highest-posterior-density regions for some parameters of interest. The analyses were repeated for a reduced data set consisting of 300 observations selected at random from the original file. For all practical purposes, the Bayesian and non-Bayesian analyses yielded identical results despite their different interpretations. Also, the asymptotic normal approximations to the true posterior distributions were excellent. Undoubtedly, this is because the likelihood functions contained a large amount of information about the parameters. Four-year-old ewes produced lambs with greater survival rates than either younger or older ewes. Female and male lambs had similar rates, and single-born lambs had a 10% higher survival rate than multiple-born lambs

Recursos genéticos animais e sistemas de exploraçao tradicionais em Portugal

In Portugal, there are 13 beef cattle breeds, 12 sheep breeds, 5 goat breeds, 2 swine breeds and 3 horse breeds identified, with total numbers of registered females, in 1999, of 70000, 136176, 43700, 6 520 and 8600, respectively. Despite the high genetic diversity represented by these native breeds, their relative contributions for national herds are only 24 p.100 for beef cattle, 6 p.100 for sheep, 7.8 p.100 for goats, 2 p.100 for swine and 15.2 p.100 for horses. The vast majority of animals raised in Portugal are crossbreds, as a result of continued crossbreeding practices with exotic germplasm. Farm size, climatic, soil and cultural diversity are the main factors influencing production systems. The extensive production system is the most typical in Portugal, namely for ruminant species. However, in terms of average herd sizes, use of products and type of enterprise, there is a clear distinction between the North and the South of Portugal. While in the North, family based enterprises are the most common, in the South, herd sizes and enterprises are larger, and generally more competitive. Approximately 40 p.100 of total native breeds have less than 5000 registered females. According to FAO standards, these breeds are in various degrees of endangerment and genetic conservation programs, as well as actions for their future utilization and management, need to be implemented

Recursos genéticos animais e sistemas de exploraçao tradicionais em Portugal

In Portugal, there are 13 beef cattle breeds, 12 sheep breeds, 5 goat breeds, 2 swine breeds and 3 horse breeds identified, with total numbers of registered females, in 1999, of 70000, 136176, 43700, 6 520 and 8600, respectively. Despite the high genetic diversity represented by these native breeds, their relative contributions for national herds are only 24 p.100 for beef cattle, 6 p.100 for sheep, 7.8 p.100 for goats, 2 p.100 for swine and 15.2 p.100 for horses. The vast majority of animals raised in Portugal are crossbreds, as a result of continued crossbreeding practices with exotic germplasm. Farm size, climatic, soil and cultural diversity are the main factors influencing production systems. The extensive production system is the most typical in Portugal, namely for ruminant species. However, in terms of average herd sizes, use of products and type of enterprise, there is a clear distinction between the North and the South of Portugal. While in the North, family based enterprises are the most common, in the South, herd sizes and enterprises are larger, and generally more competitive. Approximately 40 p.100 of total native breeds have less than 5000 registered females. According to FAO standards, these breeds are in various degrees of endangerment and genetic conservation programs, as well as actions for their future utilization and management, need to be implemented