The upstream cis-elements controlling the retina-specific expression of car
p rhodopsin gene were fully characterized in vivo. Transgenic studies demon
strated that both carp neural retina leucine zipper response-like element (
cNRE, within nucleotides (nt) -63 to -75) and carp-specific element (CSE, n
t -46 to -52) were crucial to reporter gene expression in medaka retinae. T
he retina-specific expression rates of embryos injected with nt -1 to -641
and longer fragments were much higher than those of embryos injected with n
t -1 to -138 and shorter fragments, indicating that an enhancer is located
in the nt -138 to -641 region. Retinal extracts and the probe BAT-1 (nt -90
to -120) formed two DNA-protein complexes, B1 and B2. Retinal extracts and
the probes cNRE and CSE formed the complexes N1 and C1, respectively. The
protein factors in BI and C1 were mammal-like cone-rod homeobox proteins. (
C) 2001 Federation of European Biochemical Societies. Published by Elsevier
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