ABSTRACT
This chapter reviews the strategies that have been used to investigate the detection of transgenes in early embryos and discusses these finding in relation to future progress in transgenic embryo selection and animal biotechnology. Fluorescent in situ hybridisation techniques have been developed over recent years to give rapid and reliable diagnoses of the chromosome complement of human preimplantation stage embryos and blastomere biopsies. Embryo explant cultures from 12 embryos that survived in culture for a further week were found not to carry exogenous DNA. The microinjection of DNA into the pronuclei of 1-cell embryos still remains the most efficient means to produce transgenic animals. In mouse, the production of transgenic offspring is now an established laboratory procedure, in which ∼ 15% of first generation offspring will carry integrated transgenes. The stability of pronuclear injected DNA may result from the rapid concatomerization of the microinjected construct.
