Inactivation of CMP-N-acetylneuraminic acid hydroxylase occurred prior to brain expansion during human evolution.

ABSTRACT: Humans are genetically deficient in the common mammalian sialic acid N-glycolylneuraminic acid (Neu5Gc) because of an Alu-mediated inactivating mutation of the gene encoding the enzyme CMP-N-acetylneuraminic acid (CMP-Neu5Ac) hydroxylase (CMAH). This mutation occurred after our last common ancestor with bonobos and chimpanzees, and before the origin of present-day humans. Here, we take multiple approaches to estimate the timing of this mutation in relationship to human evolutionary history. First, we have developed a method to extract and identify sialic acids from bones and bony fossils. Two Neanderthal fossils studied had clearly detectable Neu5Ac but no Neu5Gc, indicating that the CMAH mutation predated the common ancestor of humans and the Neanderthal, approximately 0.5-0.6 million yea

SUBMITTER: Chou HH 

PROVIDER: S-EPMC129338 | biostudies-literature | 2002 Sep

REPOSITORIES: biostudies-literature