Int. J. Dev. Biol. 35: 69 - 75 (1991)

Vol 35, Issue 2

Embryonic expression of beta-actin-lacZ hybrid gene injected into the fertilized ovum of the domestic fowl

Published: 1 June 1991

M Naito, K Agata, K Otsuka, K Kino, M Ohta, K Hirose, M M Perry and G Eguchi

National Institute of Animal Industry, Ibaraki, Japan.

Abstract

An experiment was carried out to investigate the expression of cloned DNA injected into the germinal disc of the chick fertilized ovum. The beta-actin-lacZ hybrid gene, MiwZ, was injected, in the closed circular form, into the cytoplasm of the germinal disc at the single-cell stage. The embryos were cultured in vitro, then in recipient eggshells up to day 4 of incubation. The survival rate of the embryos at day 4 was 42% (55/130), and the rate of embryos expressing MiwZ was 64% (35/55). Twenty-two embryos expressed the MiwZ in both embryonic and extraembryonic tissues, while the remainder expressed the MiwZ in only extraembryonic tissues. Mosaic expression was observed in most of the embryos expressing MiwZ in embryonic tissues. Expression throughout all tissues of the embryo including blood cells occurred in one case. In this case, the injected DNA was assumed to have integrated at an earlier stage. The results indicate that it is now possible to investigate the promoter activities of introduced exogenous genes as well as the effect of introduced genes on embryogenesis in early chick embryos. This technique may also facilitate the production of transgenic chicks.