Tg(Lck-Egr1)40Tmiy

A 2.3-kb genomic DNA fragment containing all coding exons and intron 1, but no 3' noncoding sequence, of the 129X1/SvJ mouse early growth response 1 gene was inserted into an expression cassette containing 3.2 kb of 5' proximal sequence from the mouse lymphocyte protein tyrosine kinase gene and the polyadenylation signal and 3'untranslated region from the human growth hormone gene. This promoter directs expression primarily to immature thymocytes. Northern blot analysis demonstrated much higher than endogenous expression in thymi of transgenic mice, but detected no transgene-derived mRNA in spleen or lymph nodes. (J:111094)