hnRNP proteins are involved in many cell functions, primarily in pre-mRNA processing.We report here a comparative analysis of the genes
of the 2xRBD members of the hnRNP family and of their expression products. Starting from the seven well characterized hnRNP members
of human and murine origin (A0, A1, A2/B1, A3, AB, D and DL) and the three MuSashI-like proteins with related RBD tandems (MSI1,
MSI2 and DAZAP1), we identified through BLAST search 12 homologous genes in the genome of Danio rerio and 10 in the genome of
Takifugu rubripes, which can be divided into three subgroups, each with its highly conserved exon/intron structure, matching perfectly the
exon/intron structures found in human and mouse genes. An exception is the gene of hnRNP A0, which is intronless consistently in all the
four species. The analysis has been supported also at the level of cDNA and EST databases and extended in this respect to other vertebrate
species, namely chicken, Xenopus laevis and Silurana tropicalis. PHYLIP 3.62 package (SEQBOOT, PROTDIST/DNADIST, NEIGHBOR,
CONSENSE) was used for all the proteins and their CDSs and human RBDs I and II to infer relevant aspects of the phylogenesis of these
proteins. Some clues to the evolution of introns in these genes have come from the analysis of their distribution in homologous genes of other
eukaryotes, namely Ciona, Drosophila, Caenorhabditis, Saccharomyces and Arabidopsis.