Germline transmission of exogenous genes in chickens using helper-free ecotropic avian leukosis virus-based vectors

Abstract
We have used vectors derived from avian leukosis viruses to transduce exogenous genes into early somatic stem cells of chicken embryos. The ecotropic helper cell line, Isolde, was used to generate stocks of NL-B vector carrying theNeo r selectable marker and theEscherichia coli lacZ gene. Microinjection of the NL-B vector directly beneath unincubated chicken embryo blastoderms resulted in infection of germline stem cells. One of the 16 male birds hatched (6.25%) from the injected embryos contained vector DNA sequences in its semen. Vector sequences were transmitted to G1 progeny at a frequency of 2.7%.Neo r andlacZ genes were transcribedin vitro in chicken embryo fibroblast cultures from transgenic embryos of the G2 progeny.