The normal mouse genomic DNA (deoxyribonucleic acid) has two EcoRI sites that encodes the enzyme tyrosinase. After the digestion with EcoRI, three various sized fragments hybridize to cDNA clone.
In this way, when an albino mice genomic DNA is subjected to similar study. It results that no DNA fragments have complementary sequences to the same cDNA. This is because there is no genomic DNA that binds to the probe. Then the aimed sequences should be absent, which denotes the albino mice are deficient to produce tyrosinase.
Thus, one possible reason is that the albino mice are lacking the portion of DNA, due to the deletion of the region that is associated to albino phenotype.