TY - JOUR
T1 - Global divergence of the human follicle mite Demodex folliculorum
T2 - persistent associations between host ancestry and mite lineages
AU - Palopoli, Michael F.
AU - Fergus, Daniel J.
AU - Minot, Samuel
AU - Pei, Dorothy T.
AU - Simison, W. Brian
AU - Fernandez-Silva, Iria
AU - Thoemmes, Megan S.
AU - Dunn, Robert Roberdeau
AU - Trautwein, Michelle
PY - 2015
Y1 - 2015
N2 - Microscopic mites of the genus Demodex live within the hair follicles of mammals and are ubiquitous symbionts of humans, but little molecular work has been done to understand their genetic diversity or transmission. Here we sampled mite DNA from 70 human hosts of diverse geographic ancestries and analyzed 241 sequences from the mitochondrial genome of the species Demodex folliculorum. Phylogenetic analyses recovered multiple deep lineages including a globally distributed lineage common among hosts of European ancestry and three lineages that primarily include hosts of Asian, African, and Latin American ancestry. To a great extent, the ancestral geography of hosts predicted the lineages of mites found on them; 27% of the total molecular variance segregated according to the regional ancestries of hosts. We found that D. folliculorum populations are stable on an individual over the course of years and that some Asian and African American hosts maintain specific mite lineages over the course of years or generations outside their geographic region of birth or ancestry. D. folliculorum haplotypes were much more likely to be shared within families and between spouses than between unrelated individuals, indicating that transmission requires close contact. Dating analyses indicated that D. folliculorum origins may predate modern humans. Overall, D. folliculorum evolution reflects ancient human population divergences, is consistent with an out-of-Africa dispersal hypothesis, and presents an excellent model system for further understanding the history of human movement.
AB - Microscopic mites of the genus Demodex live within the hair follicles of mammals and are ubiquitous symbionts of humans, but little molecular work has been done to understand their genetic diversity or transmission. Here we sampled mite DNA from 70 human hosts of diverse geographic ancestries and analyzed 241 sequences from the mitochondrial genome of the species Demodex folliculorum. Phylogenetic analyses recovered multiple deep lineages including a globally distributed lineage common among hosts of European ancestry and three lineages that primarily include hosts of Asian, African, and Latin American ancestry. To a great extent, the ancestral geography of hosts predicted the lineages of mites found on them; 27% of the total molecular variance segregated according to the regional ancestries of hosts. We found that D. folliculorum populations are stable on an individual over the course of years and that some Asian and African American hosts maintain specific mite lineages over the course of years or generations outside their geographic region of birth or ancestry. D. folliculorum haplotypes were much more likely to be shared within families and between spouses than between unrelated individuals, indicating that transmission requires close contact. Dating analyses indicated that D. folliculorum origins may predate modern humans. Overall, D. folliculorum evolution reflects ancient human population divergences, is consistent with an out-of-Africa dispersal hypothesis, and presents an excellent model system for further understanding the history of human movement.
KW - Coevolution
KW - Demodex
KW - Phylogeography
KW - Symbiosis
U2 - 10.1073/pnas.1512609112
DO - 10.1073/pnas.1512609112
M3 - Journal article
C2 - 26668374
AN - SCOPUS:84952683497
SN - 0027-8424
VL - 112
SP - 15958
EP - 15963
JO - Proceedings of the National Academy of Science of the United States of America
JF - Proceedings of the National Academy of Science of the United States of America
IS - 52
ER -