Mitochondrial Diversity of Human Head Lice (Pediculus humanus capitis) Across the Americas

A poster presentation of mitochondrial diversity of human head lice across Americas. 

Background

•Sucking lice (Phthiraptera: Anoplura) are permanent and obligate ectoparasites of eutherian mammals. These highly specialized blood-sucking insects live in close association with their hosts where they complete their entire life cycle. This relationship has led to coevolution in which parasite diversification parallels that of the host (Figure 3 of poster).

• The human head louse has coevolved with humans over millions of years (Figure 1, Figure 2 of poster). Therefore, louse molecular data is valuable for studying the evolutionary history of lice and their human hosts.

•Human head lice are genetically diverse and have 3 deeply divergent mitochondrial (mtDNA) clades, named A, B, and C.

•Clothing lice (clade A) has been known to carry three bacterial pathogens. Genotypic louse data would be valuable to determine which clades of head lice have the potential to be carriers in order to combat resistance to pediculcides.

•Previous studies suggest that the three head louse clades have different evolutionary histories. Clade A appears to be uniquely linked to its Homo sapiens host (modern humans). Clade B, however, appears to have evolved on an archaic hominin in Europe (possibly H. neanderthalensis) and later switched to modern H. sapiens. Clade C appears to have evolved on an archaic hominin in Asia (possibly H. erectus) or Africa.