Published on 06/22/2022 06:00
(credit: University of Reading/Disclosure)
While we sleep, microorganisms are frantically active in our facial hair follicles, nipples, and in our eyelashes. At night, they move from follicle to follicle in search of mating. Our skin is the ideal environment for abundant nourishment: it eats the natural sebum that cells secrete. Contrary to what was supposed, these animals, invisible to the human eye, have an anus. These and other discoveries about mites were revealed by the first genetic sequencing of the species Demodex follicurum, made by scientists from the University of Reading and Bangor University in the UK, with the help of the University of Valencia (Spain), the University of Vienna (Austria) and San Juan National University (Puerto Rico). The study was published in the journal Molecular Biology and Evolution.
British University Professor of Invertebrate Biology and co-author of the paper, Alejandra Perotti, explained to Curio the importance of sequencing. “We have been able to understand, in greater detail, by revealing the mites’ DNA, how they interact with the human species on a daily basis. For example, we now know that they are very active while we sleep,” he said in an email interview.
According to Beiruti, the study’s most important conclusion relates to the synchrony between mites and humans. “It appears that they are using our own melatonin, and they cannot produce their own melatonin. This allows them to be active and reproduce while we sleep. The skin secretes the hormone at dusk and makes us sleep. The effect in small animals, such as mites, is exactly the opposite,” the expert noted.
Adaptation
Also according to Beiruti, research has shown that mites have no UV protection. “This is because they have adapted to stay inside our pores during sunlight. These are the animals that have the fewest protein genes, with a very small genome.” These organisms, isolated within our pores, do not expose themselves to external threats, nor do they need to compete for host invasion. Hence, they became very simple organisms, endowed with tiny legs fueled by only three single-celled muscles.
The scientists also found that one of the dream genes was reversed. Adaptation gave them a special arrangement of the prominent mouthparts for collecting animals. These animals have more cells at younger ages than those in adulthood—contrary to the previous assumption that parasites reduce cell numbers early in their development. “Mites have been blamed for many things. Their long association with humans may suggest that they may also have minor but important beneficial roles, for example in keeping facial pores unclogged.”
