The divergence between human and baboon globin genes.

Complementary DNA (cDNA) was prepared with viral RNA-directed DNA polymerase from purified baboon globin messenger RNA (mRNA). Homologous and heterologous hybrids between human and baboon mRNAs and cDNAs were compared for extent of hybridisation and thermal stability. Higher mRNA inputs to the hybridizations were required to reach saturation in the heterologous cases. The melting temperature of the heterologous hybrid was 5 degrees C lower than the homologous hybrid. Between these two primates, divergence has occurred in the globin gene to a smaller extent than that possible from third position changes in the coding sequences of the divergence of total DNA. Globin cDNA prepared from baboon will not in general be useful as a probe for human globin mRNA or human globin gene sequences.