Molecular cloning of a novel cDNA from Mus muscular BALB/c mice encoding glycosyl hydrolase family 1: a homolog of human lactase-phlorizin hydrolase.

OBJECTIVE

To study the mechanism of lactose intolerance (LI) by cloning the mouse lactase cDNA and recombining a vector. METHODS Total murine RNA was isolated from the small intestine of a 4-week-old BALB/c mouse (d). Gene-specific primers were designed and synthesized according to the cDNA sequences of lactase-phlorizin hydrolase (LPH) in human, rat, and rabbit. A coding sequence (CDS) fragment was obtained using RT-PCR, and inserted into a clone vector pNEB-193, then the cDNA was sequenced and analyzed using bioinformatics.

RESULTS

The cDNA from the BALB/c mouse with 912 bp encoding 303 amino acid residues. Analysis of the deduced amino acid sequence using bioinformatics revealed that this cDNA shared extensive sequence homology with human LPH containing a conserved glycosyl hydrolase family 1 motif important for regulating lactase intolerance.

CONCLUSION

BALB/c mouse LPH cDNA (GenBank accession No: AY751548) provides a necessary foundation for study of the biological function and regulatory mechanism of the lactose intolerance in mice.