Concerted evolution of the cow epsilon 2 and epsilon 4 beta-globin genes

The nucleotide sequences of the cow epsilon 2 and epsilon 4 globin geneswere determined. The sequences were 95% identical. These genes arose via afour-gene block duplication that also gave rise to the bovine fetal (gamma)and adult (beta) genes. Their deduced amino acid sequences are unlike anypreviously reported fetal or adult globins; rather, comparison to othermammalian globin genes indicates that they are embryonic in nature. Thesequence data indicate that these two genes have converted each otherduring evolution. Pairwise comparison to the corresponding goat genes showsgreater similarity between paralogues than between more directly relatedorthologues. This is in direct contrast to the situation between the cowand goat fetal and adult genes. These observations suggest that thefrequency of DNA conversion or the fixation of conversion events may varyin different locations of the cow beta-globin cluster.