ZFIN ID: ZDB-PUB-021016-60
Artificial chromosome transgenesis reveals long-distance negative regulation of rag1 in zebrafish
Jessen, J.R.
Date: 1999
Source: Ph.D. Thesis : (Thesis)
Registered Authors: Jessen, Jason R.
Keywords: none
MeSH Terms: none
PubMed: none
Despite the essential roles played by the recombination activating genes (rag1 and rag2 ) during V(D)J recombination, the mechanisms that restrict their expression to lymphoid cells are undefined. Using a novel approach to achieve artificial chromosome transgenesis in zebrafish, we demonstrate that distal regulatory elements are critical to suppress rag1 expression in inappropriate tissues. In contrast to smaller reporter gene constructs, 125 and 75 kb artificial chromosomes containing the zebrafish rag genomic locus directed GFP expression in a pattern reflective of endogenous rag1. Mapping experiments identified a positive element 5? of rag1 that enhances GFP expression in both lymphoid and non-lymphoid tissues and a negative element 5? of rag1 that specifically suppresses GFP expression in the skeletal muscle. Our transgenic zebrafish also express GFP in olfactory neurons which we show represent an authentic rag1 expression site in zebrafish.
Ph.D. Thesis, Medical College of Georgia