Skip to main content
Premium Trial:

Request an Annual Quote

Sea of Shark DNA

By collecting ocean water where whale sharks had been spotted, researchers from the University of Copenhagen were able to able to retrieve and analyze DNA from that shark population, the Los Angeles Times reports.

The team led by Copenhagen's Philip Francis Thomsen collected 20 seawater samples from near the Al Shaheen oil field that's located offshore of Qatar. Whale sharks had recently been seen aggregating there seasonally. As the researchers report in Nature Ecology & Evolution this week, they sequenced mitochondrial DNA obtained from these samples and compared them to tissue samples that had been previously collected from 61 sharks at that same location. The mtDNA haplogroups found in the environmental DNA samples included the ones from the tissue samples, plus a few additional ones.

Through a principal components analysis of these haplogroups, Thomsen and his colleagues found that this population of whale sharks was more closely related to populations in the Indian and Pacific Oceans than ones in the Atlantic Ocean.

Along with the whale shark DNA, the researchers also picked up mackerel tuna DNA. As the LA Times notes, the two seemed correlated: when the seawater samples had high levels of shark DNA, it also had high levels of mackerel tuna DNA, and samples with low levels of shark DNA also had low mackerel tuna DNA levels. "We argue that this result most probably reflects the predator–prey relationship observed between the two species," Thomsen and his colleagues write.

The Scan

RNA Editing in Octopuses Seems to Help Acclimation to Shifts in Water Temperature

A paper in Cell reports that octopuses use RNA editing to help them adjust to different water temperatures.

Topical Compound to Block EGFR Inhibitors May Ease Skin Toxicities, Study Finds

A topical treatment described in Science Translational Medicine may limit skin toxicities seen with EGFR inhibitor therapy.

Dozen Genetic Loci Linked to Preeclampsia Risk in New GWAS

An analysis of genome-wide association study data in JAMA Cardiology finds genetic loci linked to preeclampsia that have ties to blood pressure.

Cancer Survival Linked to Mutational Burden in Pan-Cancer Analysis

A pan-cancer paper appearing in JCO Precision Oncology suggests tumor mutation patterns provide clues for predicting cancer survival that are independent of other prognostic factors.