If you have ever had hair lice and have tried to get rid of the nits, you know well how difficult it is. The female lice effectively cement their eggs to human hair, and it is a herculean task to dislodge them. However, a recent study has revealed something astonishing about the glue used by the lice to stick stubbornly to the head. Just in the way Jurassic Park portrayed the DNA of dinosaurs being preserved by mosquitos that had sucked their blood, the cement used by the lice to stick to the head preserved high quality ancient DNA from the hosts of the lice, the research said. The research, which is published in the journal Molecular Biology and Evolution, was concluded after a study of Argentinean mummies that were 2000 years old. For the study, the University of Reading collaborated with scientists at the National University of San Juan in Argentina, Bangor University in Wales, the Oxford University Museum of Natural History, and the University of Copenhagen in Denmark.
Cement secretion from glands of female lice had created eggs that attached to ancient humans thousands of years ago and trapped the skin cells from the scalp into the cement. Senior author of the article and associate professor of invertebrate biology, Alejandra Perotti, and her team sequenced genomes from the skin cells to discover that these ancient inhabitants originally came from rainforests in southern Venezuela and Colombia.
Even so, the quality of the DNA in the glue was as good as DNA retrieved from teeth and even better than that of other sources like the petrous bone of the skull. This implies that lice from ancient clothes, textile and hair would be priceless in terms of providing us with a good DNA sample of humans whose remains have long vanished.
“If you have hair, or if you have clothing, you can find nits attached,” said Perotti according to The Guardian. “We can study thousands of years of the hosts’, and lice’s natural and evolutionary history just by examining the DNA trapped in the cement.”
Examination of the ancient DNA trapped in the glue revealed genetic signatures of Merkel Cell Polyomavirus, which proves to be the earliest record of the virus.