Germline Transmission of Exogenous Genes in the Chicken

Abstract

Difficulties associated with in vitro manipulation and culture of the early chicken embryo have restricted generation of transgenic chickens to approaches that use replication-competent retroviruses. The need to produce transgenic chickens in the absence of replicating virus prompted development of a new method of gene transfer into the chicken. Microinjection of the replication-defective reticuloendotheliosis virus (REV) vector ME111 beneath unincubated chicken embryo blastoderms results in infection of germline stem cells. This vector contains genetic information exogenous to the chicken genome, including both the herpes simplex virus type 1 thymidine kinase gene and the Tn5 neomycin phosphotransferase gene. About 8 percent of male birds hatched from injected embryos contained vector DNA in their semen. All four positive males tested passed vector sequences onto their progeny. Analysis of G1 offspring showed that gonads of G0 male birds were mosaic with respect to insertion of vector provirus. Thus, primordial germ cells present in the unincubated chicken embryo blastoderm are susceptible to infection by defective REV vectors.

Generation of tissue-specific transgenic birds with lentiviral vectors

“…Foreign DNA can be efficiently introduced into avian genomes by infecting the early embryo with oncoretroviral vectors (3). A number of groups have successfully produced transgenic chickens using this general method (4,5,6).…”

Status of transgenic chicken models for developmental biology

“…Retroviral gene transfer techniques have been used the most frequently to generate transgenic chickens (Bosselman et al, 1989a(Bosselman et al, ,b, 1990Harvey et al, 2002a,b;Harvey and Ivarie, 2003;McGrew et al, 2003;Mozdziak et al, 2003), because high retroviral titers make it possible to transfer the gene of interest to many cells. Briefly, retroviruses have an RNA genome encased in a protein core containing integrase, reverse transcriptase, and protease.…”

“…Chen et al (1990) reported that a modified form of the Rous sarcoma virus containing bovine growth hormone can enter the chicken germ line. In other studies, transgenic chickens have been produced by using a replication-defective REV vector that carries an inserted growth hormone gene (Bosselman et al, 1989a(Bosselman et al, ,b, 1990. The investigators injected approximately 2,599 embryos to generate 33 males that carried that vector sequences in their semen.…”

“…The investigators injected approximately 2,599 embryos to generate 33 males that carried that vector sequences in their semen. The G0 birds transmitted the vector to the G1 progeny at a rate between 2% and 8% (Bosselman et al, 1989a). Transgenic birds carrying the lacZ gene have been produced by infecting primordial germ cells with a replication defective spleen necrosis-derived retroviral vector encoding the lacZ gene and transplanting the transformed primordial germ cells into early recipient embryos (Vick et al, 1993).…”

Successful Production of Transgenic Chicken by DNA Injection into Germinal Crescent Region (GCR) of Chicken Embryos

“…In the 1980's, on the one hand, transgenic chickens had also been produced successfully by using retroviruses as a vector (Bosselman et al,1989). Since then, other methods such as sperm vector (Nakanishi and Iritani, 1993;Hasebe et al, 1998), microinjection (Naito et al, 1991; and gene gun (Muramatsu et al, 1998) were tried to produce transgenic birds.…”