Germ Line Transmission of Carp α-Globin Gene Introduced in Rainbow Trout

Abstract

Carp α-globin gene (CαG) was introduced in rainbow trout by microinjection. Thirteen months after fertilization, 4 transgenic males matured and spermiated. Sperm from each male was used to inseminate eggs stripped from a normal rainbow trout female. Fertilization and early survival rates were equal to those of the control using a normal male. DNA was extracted from the sperm of father fish and 30-day-old embryos derived from the 4 transgenic males, and analyzed by PCR and Southern blot hybridization to determine the presence of CαG. In all the transgenic males examined, CαG was integrated into the genome of the sperm. Seven offspring out of 30 derived from the 1 male carried CαG, but no CαG was detected in offspring derived from the other males. In one of these seven offspring, about 50 copies of CαG were integrated into the genome, forming head-to-tail, head-to-head, and tail-to-tail concatemers. However, in the other 6 offspring, CαG formed only head-to-tail concatemers were observed. These findings suggest that CαG-integrated cells co-existed with non-integrated cells mosaically in the father transgenic rainbow trout. Furthermore, 2 types of CαG-integrated cells existed in them.