[Exogenous pGH gene localization on chromosomes of the transgenic pigs].

ABSTRACT

The pUC19-OMT plasmids were cut by Ssp 1 and the products in 900 bp were recovered from low-melting agarose gel and used as probes which were labeled by Digoxigenin. After being denatured, the probes were dropped on the chromosome samples which were also denatured to anneal with them. The anti-digoxigenin antibodies labeled with colloidal gold were used to act with the chromosome samples. In order to localize the exogenous pGH genes(porcine growth hormone gene) on chromosomes detected with optical microscope and improve the sensitivity, digoxigen gold signals are amplified by silver precipitation. After calculating the number of silver grains on every chromosome under the optical microscope, we analyzed the data with statistical methods. The results show that the integrating sites of exogenous pGH genes are very different among the positives. However, it is clear that the exogenous genes in one are always of the tendency to integrate in one specific site on a certain chromosome. These data are of great significance for studying the site-specific integration and the expression efficiency of exogenous genes in the future research.