cDNA cloning of mouse BLM gene, the homologue to human Bloom's syndrome gene, which is highly expressed in the testis at the mRNA level.

We cloned a cDNA encoding the mouse homologue to human Bloom's syndrome gene (BLM). The deduced amino acid sequence of mouse Blm showed 76% identity to the human sequence with very high homology in seven consecutive domains characteristic of DNA and RNA helicases. The expression of mBLM mRNA was examined in various tissues. Extremely high expression was observed in the testis as compared with other tissues. The mBLM mRNA level in the testis began to increase 12-14 days after birth, corresponding to the appearance of cells in the pachytene phase.