The principal aim of this stugy is to increase the percentage of viable blastocysts produced in vitro. The in vitro embryo production and gamete and ambryo cryopreservation techniques are eddential technologies for the ex situ conservation of animal genetic cources, so in wild as and domestic animals. This project is a contunation of prior studies which conclusions were a low nmber of blastocyts (12%) caused by two kind of anomalies: non decondensation of sperm heads and a high percentage of polyspermic fertilisation, producing haploid embryos. Presumably, the cause of these anomalies is a deficient cytoplasmatic maturatiion of prepubertal oocytes (Khatir er al.1998b). Yohida er al. (1993) showed in porcine oocytes that intracytoplasmic glutation affect sperm head decondensation. The objectives of this project are: 1)Study about precursos of cytoplasmic glutation in IVM medium: cystein, cysteamine, cystine, N-acetyl cysteine and mercptoethanol and growth factors (EGF, GH). 2) Analysis of cytoplasmic proteins (MPF complex) involved in IVM. 3)Microscopic study of cytoplasmic organelles: cortical granules, ribosomes and mitochondria during the in vivo and in vitro oocyte maturation. 4) Using the ICSI (Intracytoplasmic Sperm injection) as a way to obtain monospermic fertilization. These studies will be also performed with ovulated oocytes used as control. The importance of the in vitro embryo production is: a) Studies of biotechnology, where the number of embryos needed is high and expensive using embryos produced in vivo. b) Intensification of genetic selection due to an increase of number of born animals from selected males and females, and c) to reduce the generational time allowing born of animals from prepubertal females.
|Effective start/end date||9/07/01 → 9/07/04|