Ma. Lee et al., CHARACTERIZATION OF RAINBOW-TROUT CDNAS ENCODING A SECRETED AND MEMBRANE-BOUND IG HEAVY-CHAIN AND THE GENOMIC INTRON UPSTREAM OF THE 1ST CONSTANT EXON, Molecular immunology, 30(7), 1993, pp. 641-648
Two different rainbow trout cDNA sequences encoding a heavy chain secr
eted Ig (Hs) and a part of a membrane-bound heavy chain Ig (Hm) are re
ported. The sequences were most similar to those encoding the Ig heavy
chains (IgH) of other teleost fish. As in the Hm of the other teleost
fish the rainbow trout Hm results from the splicing of the 3' end of
the third constant exon (CH3) to the sequence encoding the membrane-bo
und domain. Analysis of a rainbow trout IgH genomic clone revealed tha
t a joining heavy chain (JH) segment, different to the one observed in
the cDNA, is located 825 bp 5' of the CH1 exon. The sequence also con
tains possible enhancer-like and octamer-like motifs.