mefi 
27.02.2021, 03:48:38.
Humble dung beetles may be ideal DNA detectors for animal surveys
Biologists wanting to identify the resident creatures of a location, be it nearby woods or a distant mountainside, could soon have new assistants to help them vacuum up a surrounding’s DNA: dung beetles. The guts of these unfussy eaters contain species-identifying mammalian DNA, a study has found, and could provide an easy, low-tech way to catalog regional biodiversity.
Using insects to sample biodiversity is “a super idea,” says Elizabeth Hadly, an environmental biologist at Stanford University who was not involved in the study. “Dung beetles are everywhere.”
Attempts to figure out a region’s biodiversity through environmental DNA (eDNA) samples are only a few decades old. Scientists sift through dirt, soil, and especially water to find loose skin flakes, mucus, and other body fluids; then, they screen these for traces of identifiable DNA to determine which animals live in the region. So far, marine science has been the biggest beneficiary of eDNA techniques, also known as DNA barcoding. DNA can persist in water for several days, allowing scientists to simply filter samples from, say, a pond to get a rough estimate of which species are present.
Rosie Drinkwater, a molecular biologist and postdoc at Queen Mary University of London, decided to test another widespread connoisseur of DNA-rich body material: the dung beetle. These invertebrates, which comprise thousands of different species within the family Scarabaeidae, feed on other animals’ feces. There are dung beetles on every continent except Antarctica, and they make their homes in environments from deserts to forests to oil palm plantations, Drinkwater says.
Dung passes through dung beetles relatively quickly, within about 48 hours. Although that’s a short window of opportunity, Drinkwater explains, it has an upside: If you get a dung beetle–gut DNA hit on a species, you can be relatively certain that animal was nearby recently.
Drinkwater cautions that the study has not yet undergone peer review, and more work is needed to test the strategy in different environments and using different beetles. Still, “Dung beetles are a smart addition to the arsenal” of eDNA tools, says Michael Kinnison.
Zdroj: Michael Price, Fri, 19 Feb 2021, 3:00 PM
https://www.sciencemag.org/news/2021/02/humble-dung-beetles-may-be-ideal-dna-detectors-animal-surveys?utm_campaign=news_daily_2021-02-23&et_rid=742570496&et_cid=3676471
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