Molecular cloning and phylogenetic analysis of canine beta-casein

A canine beta -casein cDNA was isolated from mammary tissue by polymerase c hain reaction (PCR) using degenerate primers. It encodes 250 amino acids pr otein containing the conserved sequence motif of beta -casein. It showed th e highest homology with snow-leopard (Uncia uncia) (55-62 % identity). It a lso showed 44-53% identity with human, 33-42 % identity with mouse, 29-37% identity with rat, 43-53 % identity with rabbit, 41-48% identity with pig, 44-51% identity with cattle and 44-50 % identity with sheep. A 1.2-kb mRNA was detected in mammary tissue by Northern blot analysis. Phylogenetic anal ysis revealed that canine beta -casein formed a branch with lesser panda an d snow leopard, which were grouped into carnivore.