At this point in human evolution, a certain gene, known as CMAH, that allows for the synthesis of a sugar called Neu5Gc, went missing.
University of Nevada, Reno researchers, led by College of Science Assistant Professor David Alvarez-Ponce, have analyzed 322 animal genome sequences from the National Center for Biotechnology Information looking for animals that show the presence of active CMAH genes.
Birds also lack active CMAH genes, implying that consuming animals like chicken, turkey, and geese is not associated with the harmful side effects.
Aside from dietary issues, the CMAH gene also proves to be a major factor in whether or not a transplanted organ from an animal would be accepted by a human because of the gene.
To test the feasibility of using these knockout cell enrichment approaches for pig fibroblast cells, we used ZFNs targeting CMAH
exon 6 (Figure 1a) and surrogate reporters containing either the eGFP gene alone (eGFP reporter) or eGFP and a truncated H-2Kk surface marker (MACS reporter), whose expression in cells can be recovered by a ZFN-induced frameshift mutation in CMAH
Researchers compared two groups of mice: one with a functional CMAH gene, the other with an altered CMAH gene similar to the human mutation.
However, only mice with the CMAH gene mutation experienced pancreatic beta cell failure - the cells that make and release insulin, a hormone that controls blood sugar levels.