Structural characterization and transcriptional pattern of two types of carp rhodopsin gene

This work characterizes the genomic structures of two types of carp (Cyprin us carpio) rhodopsin (cRh) gene, i.e. type I (cRh-I) and type II (cRh-II). Two types of cRh gene share only 45.6% polynucleotide identity in the upstr eam region from nucleotide - 3436 to + 97. However, three conserved regions are found. Homologies to the consensus recognition sites for transcription factors, Crx and Nrl, which are involved in photoreceptor-specific express ion, are also observed in cRh genes. With specific polymerase chain reactio n (PCR) primers, the two types of cRh gene can be clearly discriminated fro m each carp genome. Most carps exhibit both types of cRh gene, however, the re are still carps possessing either cRh-I or cRh-II. Both cRh-I and cRh-II mRNAs are expressed at an approximately equal level in both eyes extracted from a carp carrying both types of cRh gene. (C) 2000 Elsevier Science Inc . All rights reserved.