Molecular evolution in the hypervariable regions of fetuin: Comparison between human and African green monkey fetuin

Sequences of fetuin cDNA and its deduced amino acid residues from the Afric an green monkey cell line Vero were found to differ by 7.3% and 12.9%, resp ectively, from the corresponding human sequences. Most amino acid substitut ions were clustered within a small segment of the third domain (D3). Calcul ations of nonsynonymous and synonymous nucleotide substitution rates sugges t that this small segment was mutated under positive selection. cDNAs encod ing alpha(1)-antitrypsin, beta-actin and the sequences of intron 4 of alpha (1)-antitrypsin gene in human liver and Vero cells were also investigated. The results substantiated the positive selection imposed on the D3 segment.