Silent delta-globin gene in Old World monkeys.

Area of Science:

• Evolutionary biology
• Primate genetics
• Molecular anthropology

Background:

• Delta polypeptide chains are a component of adult hemoglobin in higher primates.
• Old World monkeys are unique among higher primates in lacking delta polypeptide chains.
• This suggests a recent evolutionary loss of delta globin synthesis.

Purpose of the Study:

• To investigate the presence and genetic organization of the delta globin gene in Old World monkeys.
• To determine if the absence of delta globin is due to gene deletion or other genetic alterations.
• To understand the evolutionary implications of delta globin loss in primates.

Main Methods:

• Southern blot hybridization using human globin cDNA probes.
• Restriction endonuclease digestion of genomic DNA from rhesus monkeys and baboons.
• Comparative restriction mapping of primate globin gene regions.

Main Results:

• The delta globin gene was detected in both rhesus monkeys (Macaca mulatta) and baboons (Papio papio).
• Restriction mapping of the rhesus monkey delta- and beta-globin genes revealed an organization similar to humans.
• No evidence of large DNA deletions or additions was found in the globin gene regions of these Old World monkeys.

Conclusions:

• The delta globin gene is present in Old World monkeys, despite the absence of the protein product.
• The loss of delta globin synthesis is likely due to recent evolutionary events, not large-scale gene loss.
• This finding provides insights into the evolutionary dynamics of globin gene expression in primates.