Differential expression of Hox genes during murine liver regeneration

In order to infer the Hox code during liver regeneration, Hox gene expression pattern was analyzed during liver regeneration after partial hepatectomy in mice. Total RNAs and proteins have been prepared from the liver tissues at various times after regeneration (0 h, 4 h, and 3 d) following partial hepatectomy. Using degenerate RT-PCR, cloning, and sequencing technique, expressed Hox genes were analyzed. The Hox genes belonging to the paralogous groups VIII, IX and X manifested themselves in a peculiar way during regeneration process with stage specific characteristics: Hox genes belonging to the paralogous groups IX and X were almost exclusively expressed during regeneration whereas the paralogous group VIII, especially Hoxb8 and -c8 were strongly expressed in normal liver. The proteom analysis revealed that almost 21% of the differentially expressed proteins (6 out of 29 differentially expressed protein spots) during liver regeneration turned out to be Hox genes. Furthermore, Hoxa10 and- d10 belonging to the AbdB type paralogous group X were upregulated during regeneration. These results altogether indicate that Hox genes seemed to be differentially expressed during murine liver regeneration at the transcriptional as well as translational level. Especially the Hox genes belonging to the paralogous group X such as Hoxa10 and Hoxd10 seemed to be a pail of Hox code for the murine liver regeneration.