Estudio de las fracciones proteínicas del fluido folicular porcino en la maduración, fertilización in vitro y polispermia de ovocitos de cerdo
In vitro maturation and fertilization (IVM, IVF) programs in pigs have some problems, these are low rates of cytoplasmic maturation and high percentages of polyspermy. To the present time, it is not clear if these difficulties are related to culture conditions during maturation. It has been shown th...
| Autor: | |
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2004 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:7h149q43m |
| Acceso en línea: | https://doi.org/10.24275/uami.7h149q43m |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Fertilization in vitro info:eu-repo/classification/LEM/Swine -- Reproduction info:eu-repo/classification/LEM/Cerdos -- Reproducción info:eu-repo/classification/LEM/Fertilización in vitro info:eu-repo/classification/cti/3 |
| Sumario: | In vitro maturation and fertilization (IVM, IVF) programs in pigs have some problems, these are low rates of cytoplasmic maturation and high percentages of polyspermy. To the present time, it is not clear if these difficulties are related to culture conditions during maturation. It has been shown that porcine follicular fluid (pFF) increases the oocyte nuclear and cytoplasmic maturation, evaluated by the development of the male pronucleus (mPN) after IVF. However, there is controversy about its effects, depending on the follicular size from where the pFF is obtained. The objective of this study was to evaluate the effect of complete and fractionated pFF, on IVM, IVF and polyspermy, when added to the maturation medium. Porcine oocytes were collected from prepuberal gilts. The pFF was obtained by puncture of follicles smaller than 5 mm (pFF1) and from 5.1 to 8 mm in diameter (pFF2), the pFF from both categories showed a protein concentration of 60 ± 5 mg/ml. The negative control was normalized as 100%. Both pFF1 and pFF2 when added to the IVM medium and in the presence of LH, FSH and EGF increased nuclear maturation (80%), cytoplasmic maturation increased between 371 and 400%, fertilization increased between 165 and 183% and polyspermy between 57 and 73%, as compared to the negative control. Since no significant differences were found between pFF of the two follicular types, pFF1 was selected to be fractionated by anionic exchange chromatography. Five fractions were obtained (R1, R2, R3, R4, R5), those with the most important effect were R1, R3 and R5. R1 increased fertilization by 30% and decreased polyspermy also by 30%, the latter one in the same manner as the complete pFF. R3 had an inhibitory effect on nuclear and cytoplasmic maturation. R5 increased the reinitiation of meiosis (29%), nuclear maturation (20%) and mPN development (32%).The fractions were analyzed by electrophoresis in polyacrylamide gel in presence of SDS to relate the protein band pattern to the effect on maturation, fertilization and polyspermy. In R1 a band of Mr from 45-46 kDa was found, this did not appear in other pFF fractions, for which it may be related to the reduction of polyspermy. R3 showed 2 bands (71 and 19 kDa) not present in the other regions, which may be related with its inhibitory effect. R5 showed two bands of 139 and 124 kDa not found in other fractions, these proteins may be implicated with the positive effect on maturation observed in pFF and in this region. This study shows that the protein components of pFF are relevant for the IVM, IVF and polyspermy of the porcine oocyte. It is required to perform analyses to identify the proteins that compose these fractions, so that in an isolated manner its effect can be tested in maturation media on IVM, IVF and polyspermy. Key words: in vitro maturation, in vitro fertilization, follicular fluid, follicular fluid protein fractions, porcine oocytes. |
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