EXPRESSION OF THE CMV-LACZ-GENES AND RSV- LACZ-GENES IN TRANSGENIC FISH AND MOUSE EMBRYOS

The bacterial gene for beta-galactosidase under the control of LTR fro m either human cytomegalovirus (CMV-lacZ) or the Rous sarcoma virus (R SV-lacZ) was injected into fertilized eggs of Misgurnus fossilis L. le aches and F-1 hybrid mice (CBA x C57B1). Expression of the CMV-lacZ wa s observed in almost 100% of the leach embryos and larvae for two mont hs following the first day of embryonic development. In some cases, ex pression points were located only on either the right or the left side of a fish, The spectrum of tissues expressing CMV-lacZ was decreased during embryonic development: CMV-lacZ was expressed only in fin and b ody muscles of 6- to 8-week-old leaches. In mice, the RSV-lacZ gene wa s expressed in ectoderm- and mesoderm-derived tissues of a 13-day-old embryo, and the CMV-lacZ gene was expressed in tissues derived from va rious blastophylli of a 14-day-old embryo. Distrubution of transgene e xpression is discussed with regard to authors' and published data.