957 resultados para equine oocyte maturation


Relevância:

80.00% 80.00%

Publicador:

Resumo:

The aim of this study was to evaluate the suitability of a commercial kit for bovine embryo vitrification for cryopreserving cat oocytes and to evaluate comparatively the effects of its use with slow freezing procedure on cryotolerance in terms of morphology and oocyte resumption of meiosis. Germinal vesicle stage oocytes isolated from cat ovaries were either vitrified (n=72) using a vitrification kit for bovine embryo or slow frozen (n=69) by exposing oocyte to ethylene glycol solution before being transferred to a programmable embryo freezer. After thawing and warming, oocytes were cultured for 48h and then were examined for meiosis resumption using bisbenzimide fluorescent staining (Hoechst 33342). Fresh immature oocytes (n=92) were used as the control group. The proportion of oocytes recovered in a morphologically normal state after thawing/warming was significantly higher in frozen oocytes (94.5%) than in the vitrified ones (75%, p<0.01). Morphological integrity after culture was similar in vitrified (73.6%) and slow frozen oocytes (76.8%); however, only 37.5% of the morphologically normal oocytes resumed meiosis after vitrification compared to 60.9% of those submitted to slow freezing procedure (p<0.01). Fresh oocytes showed higher morphological integrity (91.3%) and meiosis resumption rates (82.6%, p<0.002) than cryopreserved oocytes, irrespective of the procedure used. These results suggest that immature cat oocytes vitrified with a kit for bovine embryos retain their capacity to resume meiosis after warming and culture, albeit at lower rates than slow frozen oocytes. Vitrification and slow freezing methods show similar proportions of oocytes with normal morphology after culture, which demonstrate that thawed and warmed oocytes that resist to cryodamage have the same chances to maintain their integrity after 48h of culture. © 2012 Blackwell Verlag GmbH.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Pós-graduação em Ciência Animal - FMVA

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Pós-graduação em Medicina Veterinária - FCAV

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

In vitro-produced bovine embryos become infected after exposure to bovine Herpesvirus type 5 (BoHV-5), yet no changes in developmental rates, mitochondrial activity and inhibition of apoptosis are detected in comparison to unexposed embryos. Thus, the aim of the present study was to assess the transcription of mitochondria-mediated apoptosis genes using TaqMan real-time polymerase chain reaction. Transcripts of mcl-1, caspase-2, -3, Apaf-1 and Bax genes were measured after exposure to BoHV-5 in vitro. Mitochondrial dehydrogenase activity was evaluated by MIT test and compared between groups of exposed and unexposed embryos, at day 7 of development. The rate of oocyte maturation was assessed by the extrusion of the first polar body. In summary, BoHV-5 exposed embryos retained their viability, mitochondrial dehydrogenase activity and displayed up-regulation of transcription of survival mcl-1 gene and down-regulation of Bax transcription in relation to mitochondria-mediated pathway which might improve embryo viability. These findings demonstrate that BoHV-5 exposed embryos maintain their viability and mitochondrial dehydrogenase activity with no compromise of embryos produced in vitro. (c) 2013 Elsevier Ltd. All rights reserved.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The Brazilian livestock stands out for having the world largest commercial herd of cattle and leads meat exportation and production of bovine embryos. The in vitro production (IVP) of embryos is considered an effective option to overcome problems such as infertility in cows with high economic value and also for genetic improvement of cattle. The in vitro oocyte maturation is an essential step to the success of IVP, but is still considered poor when compared to in vivo maturation. Recent studies have suggeested an important role of Fibroblast Growth Factor 10 (FGF10) on the in vitro maturation of oocytes, which favored the expression of genes related to oocyte maturation and cumulus cell expansion. Aware that maturity stage influences the final production of blastocysts, we aimed study to verify if the addition of FGF10 into the maturation medium is able to affect positively the IVP of bovine embryos. Hence, FGF10 was added to maturation in five different concentrations: 0.5 ng/mL (group 0.5), 2.5 ng/mL (group 2.5), 5 ng/mL (group 5), 10 ng/mL (group 10) and 50 ng/mL (group 50). Additionally, two other maturation groups were used, group BSA (Bovine Serum Albumin, 4 mg/mL) and group FCS (Fetal Calf Serum, 10%). The rates of cleavage, morula and blastocyst were analyzed by Analysis of Variance (ANOVA), differences of P<0.05 were considered significant. Cleavage rates did not differ between the seven groups. On the other hand, morula rate on FCS group was higher than groups BSA, 0.5, 10 and 50 (P<0.05), but did not differ among groups treated with intermediate doses of FGF10 (2.5 and 5). FCS group presented higher blastocyst rate compared to all other groups that were well below the FCS group (P<0.0001). Therefore, the use of FGF10 during oocyte maturation did not affect positively embryo development on the IVP of bovine embryos

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Pós-graduação em Medicina Veterinária - FCAV