Comparison of the nucleotide sequences from the coding regions of the four mammalian β-globin genes shows that different parts of these genes have evolved at two different rates. Those codons designating amino acids 1-20, 41-91 and 109-146 have accumulated substitutions in a random fashion as the molecular clock hypothesis would predict. The codons at positions 21-40 and 91 to 108 behave as if they evolved at a much slower rate. Each of the slowly evolved regions contains an intron. Conservation of the coding sequences flanking the introns are hypothesized to be the result of cross-species gene exchange.
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Immunology and Microbiology(all)
- Applied Mathematics
- Modeling and Simulation
- Statistics and Probability