Histone H2B variants from the erythrocytes of an amphibian, a reptile and a bird

Histones H2B have been isolated from the terminally differentiated diploid erythrocytes of three different classes, amphibia (Xenopus laevis), reptilia (Crocodilus niloticus) and aves (Gallus domesticus). Partial amino acid sequences revealed three regions of sequence variation, each variant involving a single amino acid substitution.