Universidad de Buenos Aires Facultad de Ciencias...
The in vitro embryo production is inefficient in swine. This comprises several reproductive biotechniques such as: In vitro maturation (IVM), in vitro Fertilization (IVF), embryo culture (EC). Nuclear and cytoplasmic maturation of oocytes are essential to attain a good performance. In recent years t...
Guardado en:
| Autor principal: | |
|---|---|
| Otros Autores: | |
| Formato: | Tesis de maestría acceptedVersion |
| Lenguaje: | Español |
| Publicado: |
Universidad de Buenos Aires. Facultad de Ciencias Veterinarias
2016
|
| Materias: | |
| Acceso en línea: | http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avemaster&cl=CL1&d=HWA_1461 https://repositoriouba.sisbi.uba.ar/gsdl/collect/avemaster/index/assoc/HWA_1461.dir/1461.PDF |
| Aporte de: |
| Sumario: | The in vitro embryo production is inefficient in swine. This comprises several reproductive biotechniques such as: In vitro maturation (IVM), in vitro Fertilization (IVF), embryo culture (EC). Nuclear and cytoplasmic maturation of oocytes are essential to attain a good performance. In recent years the IVM has been properly accomplished, but cytoplasmic maturation has not. The consequence is the low rate of male pronuclei (MPN) and high polyspermy, suggesting that IVM technique should be improved. For this specific purposes, the study of the oocyte cumulus complex (OCC) requirements in in vitro environment are necessary. Glucose is fundamental for in vitro maturation; being metabolized in cumulus cells through different metabolic pathways. However the excess of glucose can cause unwanted lipid and protein glycosylations and affect OCC functionality. Glucose uptake by cells occurs through specific transporters (GLUT) including GLUT 4, insulin dependent glucose transporter. Gonadotropins and Insulin are hormones frequently used in IVM, but their individual effects have not been completely studied yet. The goal of this work was to study glucose intake to the porcine OCC during in vitro maturation and their possible hormonal regulation. The effect of gonadotropins (FSH and LH) and insulin on glucose intake and consumption in the pig OCC during IVM and the hormonal influence on nuclear and cytoplasmic oocyte maturation was analysed. The presence of GLUT 4 was also determined. The OCCs were matured under three treatments: gonadotropins, insulin and both combined. The percentage of nuclear maturation, glucose uptake and incorporation of a non-metabolizable analogue (6-NBDG) was evaluated. To analyse cytoplasmic maturation IVF was conducted. The presence of GLUT 4 was determined on immature and mature OCCs by immunocytochemistry.\nThe percentage of oocytes nuclearly mature increased significantly by gonadotropins (FSH and LH) and gonadotropins combined with insulin (p <0.0001). Meanwhile, insulin alone had no effect on nuclear maturation. However, a significant increase was observed on cytoplasmic maturation in OCC matured with insulin, gonadotropin and the combination of both (p <0.0001). Gonadotropins showed a positive effect on glucose uptake, but Insulin had no (p <0.0001). Localization of GLUT 4 in porcine oocyte and cumulus cells was also determined. Both hormones kept the presence of GLUT 4 during IVM. However, neither insulin nor gonadotropins showed effect on the incorporation of 6-NBDG the OCC (p> 0.05).\nIn conclusion, gonadotropins and insulin showed different effects during in vitro maturation, the first ones increases the maturation rate and glucose consumption, but do not regulate the incorporation rate of sugar. Meanwhile insulin improves cytoplasmic maturation, probably as a trophic factor without effect on glucose consumption and intake. The presence of GLUT 4 persists with both hormones and this effect might become relevant during embryo culture. |
|---|