Connect with us

Healthcare

Deep-sea Mussels Still Show Biological Rhythms Tracking Sunlight, Tides

Published

on

ROV Victor6000 samples mussels under red light at 1688 meters depth. Researchers found that deep-sea mussels follow rhythms of the tides and can perceive light. Image credit: Ifremer/Victor6000/Momarsat 2017

Like many land animals, marine organisms follow daily and seasonal clocks—in the water, those clocks are set by the cadence of the sun and the moon. But researchers hadn’t known if deep-sea creatures also exhibit biological rhythms, tucked away in remote and sunless environments. They do, confirms a recent study in Nature Communications. Observations of deep-sea mussels, both at depth and in the lab, confirm regular and rhythmic patterns in their behavior and their gene expression, for instance, tracking the roughly 12-hour cycles of the tides.

Until submersible exploration in the 1970s, “people thought the deep sea was dark, extreme, with no life,” says coauthor Audrey Mat, a marine biologist and chronobiologist who led the new work as a postdoc working jointly with Université de Bretagne Occidentale and Ifremer, France. The 1977 discovery of hydrothermal vents upended conventional visions of a desolate deep sea, suggesting one rich in biomass. But researchers still know little about how life in these ecosystems changes over daily or seasonal timeframes, nor what environmental cues could drive biological cycles such as migration or spawning.

Mat and coauthors probed these questions through both field and lab work. First, they used video recordings of deep-sea mussels to look for cues of possible rhythmic behavior. The recordings, collected between July and August 2014, showed the mussels opening and closing in a regular pattern, roughly every 12 hours. The team then used a remotely operated submersible to collect mussels from a hydrothermal vent nearly 1,700 meters deep. The sub collected and preserved mussels on the seafloor under red light roughly every two hours over the course of about 24 hours. Back onshore, the researchers compared each time stamped sample to see how gene expression changed over the course of the day. They observed regular oscillations in gene expression every 12 hours and 24 minutes, aligned with the tides.

Then, in a second experiment, the team brought the same species of deep-sea mussels into aquariums in the lab and exposed them to 24-hour cycles of daylight and darkness over a 72-hour period. Again, they found regular oscillations in gene expression. But this time, the oscillations tracked day and night rather than the tides, Mat says, suggesting the mussels can perceive light.

Researchers launch the ROV Victor6000 to collect deepwater samples. Image credit: Audrey Mat/Momarsat 2017

In addition to confirming that these organisms follow biological rhythms, the findings also suggest deep-sea mussels, thought to have evolved from a shallow-water ancestor, may have retained the ability to see light even as they moved into deeper water, Mat says. Importantly, the laboratory findings suggest that submersibles using a full-spectrum white light may disturb the animals’ rhythms; better to use red light as they did in this study.

Annie Mercier, a marine ecologist at Memorial University in Newfoundland, Canada, who was not involved in the new work, notes that these findings add to pioneering research over the last decade that’s already revealed biological rhythms in other deep-sea organisms, such as crustaceans, corals, and echinoderms. Evidence for deep-sea biological rhythms in general, she says, “has been gaining traction for a number of years already.” But the use of molecular tools to track these rhythms through gene expression is quite novel, Mercier says.

The fundamental question for the field now, she adds, is why marine organisms are rhythmic or periodic in the first place. Some benefits of life in rhythm are intuitive, such as males and females coordinating their spawning times. But whether rhythm genes in deep-sea mussels are a vestige of shallow-water evolution, or whether the mussels may actually be responding to something they perceive at depth besides light and tidal currents, has yet to be resolved. Teasing this out is one future research direction. “There could be cues,” Mercier says, “we’re not considering yet.”

Original Post: blog.pnas.org

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Healthcare

‘The Scientists, They’re Learning More’: a Defiant Biden Defends the CDC Amid Mounting Criticism

Published

on

WASHINGTON — President Biden on Wednesday defended the Centers for Disease Control and Prevention, amid mounting criticism of the agency’s repeated struggles to communicate basic public health guidance.

But instead of conceding that the agency is fundamentally flawed, or that his top health officials have underperformed, Biden attributed the communications issues to the ever-changing nature of the Covid-19 pandemic, and of science itself.

Read the rest…

Source: statnews.com

Continue Reading

Healthcare

Regenerative Med Biotech ProKidney Inks $825M Merger to Back CKD Cell Therapy

Published

on

ProKidney is going public in a SPAC merger that infuses the biotech with $825 million for Phase 3 tests and manufacturing of its autologous cell therapy for chronic kidney disease. More than slowing the decline in organ function, ProKidney says its cell therapy offers the potential to reverse injury caused by the condition.

Original Post: medcitynews.com

Continue Reading

Healthcare

Metabucks: Microsoft Offers $69 Billion to Buy Activision Blizzard

Published

on

By

Microsoft just announced its intention to buy video game developer, Activision Blizzard, for almost $70 billion. This has some people speculating about Microsoft’s future metaverse aspirations.

Source: choice.npr.org

Continue Reading

Trending

Top100Biz.com