We’ve updated our Privacy Policy to make it clearer how we use your personal data.

News   Sep 09, 2020
| Original story from Cornell University

A locally disappeared tree frog species from Parque Nacional da Serra dos Órgãos, Brazil, which has not been registered since 1977, and was rediscovered by eDNA. Credit: Leo Malagoli.

Scientists have detected signs of a frog listed extinct and not seen since 1968, using an innovative technique to locate declining and missing species in two regions of Brazil.The frog, Megaelosia bocainensis, was among seven total species – including four other declining species, and two that had disappeared locally for many years – that were detected. The findings appeared in a paper, “Lost and Found: Frogs in a Biodiversity Hotspot Rediscovered with Environmental DNA,” published in August in Molecular Ecology.

In the study, the researchers collected and screened environmental DNA (eDNA) in the biodiverse Atlantic Coastal Forest and Cerrado grasslands of Brazil.

The eDNA technique offers a way to survey that can confirm the presence of species undetected by traditional methods, providing a tool for conservation scientists to evaluate the presence of threatened species, especially those with low population densities and those not seen in years.

After careful research to identify species at various levels of threat in these regions of Brazil, the researchers used the eDNA method to search for 30 target amphibian species in six localities where the frogs were known to previously live.

“Little bits of DNA in the environment don’t tell us about how many individuals there are or whether those individuals are healthy, but it does tell us that the species is still present,” said senior author Kelly Zamudio, the Goldwin Smith Professor of Ecology and Evolutionary Biology in the College of Arts and Sciences.

“This is one more kind of survey data, and for species that are declining or locally disappeared, it not only means they are there, but there’s now the potential to study them in more detail,” she said, noting that for many species, very little is known.

Around the world, conservationists have been challenged to keep pace with declining and disappearing amphibians. At the same time, living organisms leave DNA traces in the soil, water and air. Now, scientists are increasingly using highly sensitive sampling techniques to detect eDNA for conservation purposes.

In the study, the researchers targeted 13 frog species that have totally disappeared and are presumed extinct; 12 frogs that have disappeared locally but are still found in other parts of their range; and five species that were once very abundant and are still there but hard to find.

The researchers hiked into the sampling sites carrying battery packs, a shoebox-sized peristaltic pump and backpacks of sterile tubing. They used the pump and tubing to draw up to 60 liters of stream or pond water through a capsule fitted with a filter for capturing DNA. A buffer was then applied to stabilize and preserve the DNA on the filter.

Back in the lab, the researchers extracted the DNA, genetically sequenced it, weeded out genetic material from humans, pigs, chickens and other organisms until they could isolate all the frog DNA.

“Now you’ve got a subset of genetic sequences that we know only belong to frogs, and then it’s step by step, going finer and finer, until you get to the genus and species you are looking for,” Zamudio said.

Identifying M. bocainensis required clever detective work: The species disappeared long ago, and there were no tissues from which to extract DNA for comparison with the eDNA. But the researchers did have the sequences for all the sister species in the genus Megaelosia and they knew the ranges of the sister species and M. bocainensis.

“We know there’s a Megaelosia there,” Zamudio said, “we just don’t know which one it is, but the only one that has ever been reported there historically is the one that went missing. Do we believe it? That’s how far the analysis can take us.”ReferenceLopes CM, Baêta D, Valentini A, et al. Lost and found: Frogs in a biodiversity hotspot rediscovered with environmental DNA. Molecular Ecology. doi:10.1111/mec.15594This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source.

Children Exposed to Secondhand Smoke Spend More Time in Hospital

Children who are exposed to tobacco have higher rates of hospital admissions after visiting emergency departments or urgent care facilities, according to a new study.

A Genetically-Encoded Birth Control for Pest Organisms

Research approach provides the foundations for scientists to be able to prevent genetically modified organisms (GMOs) from reproducing with wild organisms.

Warming Waters Confuse and Threaten Many Shellfish

Ocean warming is paradoxically driving bottom-dwelling invertebrates – including sea scallops, blue mussels, surfclams and quahogs that are valuable to the shellfish industry – into warmer waters and threatening their survival.

Like what you just read? You can find similar content on the communities below.

To personalize the content you see on Technology Networks homepage, Log In or Subscribe for Free

Webinar

Source: https://www.technologynetworks.com/applied-sciences/news/extinct-frogs-rediscovered-thanks-to-environmental-dna-analysis-340252

Frogs, Environmental DNA, Species, Extinction, Natural environment

World news – US – “Extinct” Frogs Rediscovered Thanks to Environmental DNA Analysis

En s’appuyant sur ses expertises dans les domaines du digital, des technologies et des process , CSS Engineering vous accompagne dans vos chantiers de transformation les plus ambitieux et vous aide à faire émerger de nouvelles idées, de nouvelles offres, de nouveaux modes de collaboration, de nouvelles manières de produire et de vendre.

CSS Engineering s’implique dans les projets de chaque client comme si c’était les siens. Nous croyons qu’une société de conseil devrait être plus que d’un conseiller. Nous nous mettons à la place de nos clients, pour aligner nos incitations à leurs objectifs, et collaborer pour débloquer le plein potentiel de leur entreprise. Cela établit des relations profondes et agréables.

Nos services:

  1. Création des sites web professionnels
  2. Hébergement web haute performance et illimité
  3. Vente et installation des caméras de vidéo surveillance
  4. Vente et installation des système de sécurité et d’alarme
  5. E-Marketing

Toutes nos réalisations ici https://www.css-engineering.com/en/works/

LEAVE A REPLY

Please enter your comment!
Please enter your name here