Sequence variability of 28 actin genes from various species has been examined by pairwice comparison.
The nucleotide replacement ratio β and the amino acid mutation ratio α were calculated using sequence information analysis program AUTO developed by us for 16-bit personal computer.
It was found that, 1) nucleotide replacements occurred mainly at the third letter positions in codons, 2) about l0% of gene nucleotides has been replaced between actins with identical amino acid sequences.