Comparative genomics reveals gene-specific and shared regulatory sequences in the spermatid-expressed mammalian Odf1, Prm1, Prm2, Tnp1, and Tnp2 genes

The comparative genomics of the Odf1, Prm1, Prm2, Tnp1, and Tnp2 genes in 13-21 diverse mammalian species reveals striking similarities and differences in the sequences that probably function in the transcriptional and translational regulation of gene expression in haploid spermatogenic cells, spermatids. The 5′ flanking regions contain putative TATA boxes and cAMP-response elements (CREs), but the TATA boxes and CREs exhibit gene-specific sequences, and an overwhelming majority of CREs differ from the consensus sequence. The 5′ and 3′ UTRs contain highly conserved gene-specific sequences including canonical and noncanonical poly(A) signals and a suboptimal context for the Tnp2 translation initiation codon. The conservation of the 5′ UTR is unexpected because mRNA translation in spermatids is thought to be regulated primarily by the 3′ UTR. Finally, all of the genes contain a single intron, implying that retroposons are rarely created from mRNAs that are expressed in spermatids.