One of the Demodex specimens we collected (Photo credit: Dan Fergus)
Our subject: Demodex mites, the microscopic parasites living in the hair follicles of numerous mammals, including humans.
We’re interested in studying the evolution and diversification of Demodex mites – particularly the two species associated with humans, Demodex folliculorum and Demodex brevis. Specifically, we want to use the information encoded in Demodex DNA to map the mites’ “family tree” and see how closely that tracks our own human family tree.
Our first task was to physically collect the critters – something we knew would be tricky. Although previous research (based on human cadavers) suggests that all adults have them, most researchers have only been able to collect mites off of 15% of the people they sampled when gently expressing sebum from pores (much like what an aesthetician does during a facial).
Sure enough – after sampling 223 volunteers during public events like the Science Online 2013 reception, Darwin Day, and Science Thursdays – we were able to successfully collect mites from 33 people (and surprise, surprise at a recovery rate of 15%).
Anecdotally, our mites seem to be patchily distributed – If we find one mite on a person, we often find several. In fact, we’ve collected over 60 mites from those 33 individuals. Some of us also think there might be a correlation between alcohol consumption and mite recovery – we noticed that we tend to collect mites from more individuals when we sample at events where people have been imbibing alcoholic beverages. Then again, this observation could easily be confounded with time of day – those events all occurred in the evening, when mites are more active and in quest of mates. We could easily parse out these effects, though, if anyone is up for an experiment…
But we digress… We took pictures of each and every mite we collected during these events and today are pleased to share with you our face mite photo gallery: http://mymites.yourwildlife.org/ (Note each photo is labeled with a unique participant number to protect participants’ privacy – if you participated in the project and can’t remember your number, drop us an email and we can remind you!)
In the gallery, we invite you to behold the splendor of the face mite – Check out the subtle differences in their size, shape and texture. Watch them wriggle their cute little legs on the posted videos.
And what’s next for Meet Your Mites? Our team has been busy at the lab bench refining methods for extracting and sequencing mite DNA, in preparation for building the mite family tree. To date, we’ve sequenced DNA from six mites and have 19 more in queue. We’re hoping to expand our sample collection to include volunteers from a diverse number of countries — Check out our map of participants who’ve dropped by the Museum so far – we’re not doing so bad…