Induction Of Expression Of HOXa-10 Gene By Progesterone And Establishment Of Transgenic Pigs

Litter size in the sow that is a key factor of pig productivity. The traditional breeding has limititons in improving porcine reproductive traits, which is time consuming, and not accurate. More efficient, more accurately, more proactive transgenic technology can greatly shorten the breeding cycles, accelerate the process of breeding. Previous studies showed that the HOXa-10 gene plays important roles in development of the female reproductive system, construction of endometrial morphology, embryonic development, establishment of endometrial receptivity, embryonic orientation and adherence. Meanwhile, it is regulated by many factors such as estrogen, progesterone, leukemia inhibitor factor(LIF), and other factors. This study is to investigate the induction of expression of the HOXa-10 gene by progesterone and establishment of transgenic. The main results were listed as follows:1. The expression change of HOXa-10 in pregnant mice through injection of progesterone. Pregnant mice were injected by progesterone through peritoneum. The expression level of HOXa-10 gene in endometrium tissues of mice treated was detected with RT-PCR. On the 4th day, the expression level of HOXa-10 gene between mice that were injected by 2mg progesterone and untreated was not significant (p>0.05). On the 5th day, the expression level of HOXa-10 gene in mice that were injected by 2mg and 4mg progesterone is significantly higher than those of untreated (p<0.05). On the 6th day, the expression level of HOXa-10 gene in mice treated and untreated was not significant (p>0.05). These results showed that HOXa-10 expression was accurately induced by progesterone in pregnancy mice at 5th day, which is at implantation. Overexpression of HOXa-10 in the mice endometrium during implantation was induced of increasing progesterone concentration. When embryo implantation was finished, expression of HOXa-10 mice embryo implantation was not induced ofafter increasing progesterone concentration.2. HOXa-10 transgenic pigs were established by pronuclear microinjection. To get more embryos, donor pigs were treated for superovulation. Receptors were transplanted embryos by surgery. A total of 13 receptor sows were tranfered with 328 embryos. There are 2601-cells and 68 2-cells. There are 25.23 embryos in per receptor. At last, we got 3 pregnant sows, and 19 piglets were born. There are 3 weak pigs and 1 dead pigs. The pregnancy rate was about 23.08%, and the embryo survival rate was about 5.79%.3. It was identified to carry the HOXa-10 gene by PCR analysis and Southern blot analysis. We got 1 pig carrying the HOXa-10 gene.