Selection of in vitro produced, transgenic embryos by nested PCR for efficient production of transgenic goats

The production of valuable pharmaceutical proteins using transgenic animals as bioreactors has become one of the goals of biotechnology, However, the efficiency of producing transgenic animals by means of pronuclear microinje ction is low, This may be attributed in part to the low integration rate of foreign DNA. Therefore, a large number of recipients are required to produ ce transgenic animals. We recently developed a transgenic procedure that co mbined the techniques of goat oocyte in vitro maturation (IVM), in vitro fe rtilization (IVF), microinjection, preimplantation selection of the transge nic embryos with nested PCR and transferring the transgenic embryos into th e recipient goat uterus to produce transgenic goats. Thirty-seven transgeni c embryos determined by nested PCR were transferred to thirty-two recipient goats. In the end, four live-born kids were produced. As predicted, all th e live kids were transgenic as identified by PCR as well as Southern blot h ybridization, The integration rate was 100% (4/4) which was completely in a ccordance with the results of embryo preimplantation detection. The results showed a significant decrease in the number of recipients required as only 8 recipients (32/4) were needed to obtain one live transgenic goat. We sug gest that the transgenic system described herein may provide an improved wa y to efficiently produce transgenic goats on a large scale. (C) 2001 by Els evier Science Inc.