Figure 3.

Phylogenetic trees for EMPs and casein-salivary proteins. MEGA II was used to construct gene trees based on the neighbor-joining method and to calculate substitution rates and bootstrap values. Both trees were drawn based on the timing of the inferred first gene duplication. (A) A phylogenetic tree for the three EMPs was constructed based on the amino acid sequences coded by exons 2–4, which are conserved among all EMP genes. The topology was the same when using sequences coded by exons 2 and 3. (B) A phylogenetic tree for Ca-sensitive CSN and three salivary protein genes was constructed based on the nucleotide sequences of the last exons (3′ UTR): exon 16 of CSN1S1, exon 18 of bovine CSN1S2 (human has two pseudogenes), exon 9 of CSN2, and exon 6 of STATH/HTNs. The same topology was obtained when using human CSN1S2L2. No ubiquitous repeat sequences were identified in these regions.