Production Of FSH Transgenic Pigs

China is the largest pigs producing and pork consuming country in the world, and the pig industry plays an important role in the national economy of China. Reproductive traits are economically important traits in pig industry, which have low heritability and are controlled by complicated polygenes, environment, nutrition, age, etc. Litter size is an important index for measuring the sow fertility, which is influenced by ovulation rate, conception rate, embryo surviving rate, environmental effect etc., and this performance is hardly improved by traditional approaches. Since Gurdon firstly produced transgenic mouse at 1980, transgenic technologies have been gradually applied to improve production performances, including reproductive traits in farm animals. Previous reports showed that FSH is a major gene underlying litter size in pigs. This study aimed to produce FSH transgenic pig by using somatic cell nuclear Transfer (SCNT).In this study, the FSHα-BAC vector from Erhualian pig was modified by defectiveλprophage-mediated homologous recombination. First, the Neo gene was inserted into the BAC to produce anti-G418 vector. Second, the reconstructed BACs (FSH a-loxp-Neo-loxp-BAC) and FSH (3-loxp-Neo-loxp-BAC were electrically transferred into the Large White fetal fibroblast cells together. Third, transgenic cells were microinjected into the MⅡphase oocytes when stable expression of transgenic cells after G418 selection was obtained. Thereafter, electric fused and active were performed in the fused embryos, and chemically auxiliary activated for 3～4h. Lastly,2～4 cells stage embryos were transplanted into the deep part of oviduct by surgery. In this study, BAC-mediated transgenic technology overcomed the problems such as the higher copy number of trans-gene and uncovered elements of gene. And high denucleation rates were obtained via Spindle-view denucleation system. The results paved the crucial road to produce FSH transgenic pigs with desirable reproductive traits.