[Expression of the beta-galactosidase gene in transgenic embryos of the loach Misgurnus fossilis L].

In order to study the topological characteristics of transgene expression in individuals, early loach embryos were injected with recombinant plasmid fragment, containing lacZ gene under the control of Raus sarcoma virus LTR. The expression of RSV-lacZ construct was found out in 80% of twenty-hours' embryos, 100% 2-3 days' embryos and 40% of 6-8 days' frys. Point and dot expression was observes on the surface of the head, muscle segments, the yolk sac, in the yolk, on the caudal fin. The number, size and intensity of expression dots varied in different individuals and decreased in the course of embryo development. The presence of RSV-lacZ sequences was found in 57% of 19 days frys. The variegation causes of transgene expression are discussed.