Gene structure of RBM12 and CPNE1 and sharing of promoter and non-coding exons between the two genes in human, mouse and zebrafish. A. Human. Representative cDNAs are [GenBank: NM_152927] for CPNE1, and [GenBank: NM_006047] for RBM12; B. Mouse. Representative cDNAs are [GenBank: NM_170588] for CPNE1, and [GenBank: NM_029397] for RBM12; C. zebrafish. There are two copies for each gene in the zebrafish genome, arranged in a head-to-head direction. The duplicated copies of the genes in zebrafish may pose problem to knock-out experiments in the species. D. partial sequence alignment between zebrafish RBM12 [GenBank: EB783076] and zebrafish CPNE1 [GenBank: NM_199699], labelled as "copine III, like" in NCBI) for the non-coding exon 1 and succeeding sequences. The one nucleotide difference (indicated by arrow) could be due to either polymorphism on the site or a sequencing error. Other sequences that share first exon with [GenBank: EB783076], and therefore may also share promoters with CPNE1 cDNA [GenBank: NM_199699] include: [GenBank: EB832449, DT271069, DT222776 and EB775439] etc.