Our paper (led by Erica – Yay), a close collaboration with the ever-wise Stefan Ruhl, on the complex evolution of the smaller one of the two salivary mucins, MUC7, is now published – It is open access and here is the link.
Our great press office, particularly Charlotte Hsu made a nice summary of the work. Here is the link.
This is an abundant, saliva specific protein – It is known to interact with microbes. And it is a mucin, meaning that it has these characteristics subexonic repeats that are highly glycosylated. What we found is an extraordinary, recurrent and adaptive variation in the copy number of these repeats among primates.
From an evolutionary point of view, the most interesting issue for me is the apparent “modularity” of the individual repeats. These repeats, by expanding and shrinking from one lineage to another, seem to adjust the glycosylation potential of the protein.
From an anthropological point of view, two interesting questions have emerged. First, has the adaptive variation in MUC7 subexonic repeat copy number evolved to cope with pathogenic pressures or changes in diet or both? Second, what is happening within species and especially among humans (wink wink nudge nudge, next paper!!!).
Exciting times! Many thanks to all involved, including our very smart undergraduates who did some of the grunt work for this study.