Navigation Links
Sensing the light, but not to see
Date:2/6/2013

WOODS HOLE, MASS. -- Among the animals that are appealing "cover models" for scientific journals, lancelets don't spring readily to mind. Slender, limbless, primitive blobs that look pretty much the same end to end, lancelets "are extremely boring. I wouldn't recommend them for a home aquarium," says Enrico Nasi, adjunct senior scientist at the Marine Biological Laboratory (MBL). Yet Nasi and his collaborators managed to land a lancelet on the cover of the Journal of Neuroscience last December. These simple chordates, they discovered, offer insight into our own biological clocks.

Nasi and his wife, MBL adjunct scientist Maria del Pilar Gomez, are interested in phototransduction, the conversion of light by light-sensitive cells into electrical signals that are sent to the brain. The lancelet, also called amphioxus, doesn't have eyes or a true brain. But what it does have in surprising abundance is melanopsin, a photopigment that is also produced by the third class of light-sensitive cells in the mammalian retina, besides the rods and cones. This third class of cells, called "intrinsically photosensitive retinal ganglion cells" (ipRGCs), were discovered in 2002 by Brown University's David Berson and colleagues. Now sometimes called "circadian receptors," they are involved in non-visual, light-dependent functions, such as adjustment of the animal's circadian rhythms.

"It seemed like colossal overkill that amphioxus have melanopsin-producing cells," Nasi says. "These animals do nothing. If you switch on a light, they dance and float to the top of the tank, and then they drop back down to the bottom. That's it for the day." But that mystery aside, Gomez and Nasi realized that studying amphioxus could help reveal the evolutionary history of the circadian receptors.

As so it has. In 2009, Gomez and Nasi isolated the animal's melanopsin-producing cells and described how they transduce light. In their recent paper, they tackled the puzzling question of why the light response of these amphioxus cells is several orders of magnitude higher than that of their more sophisticated, presumed descendents, the ipRGCs. (In mammals, the ipRGCs relay information on light and dark to the biological clock in the hypothalamus, where it is crucial for the regulation of circadian rhythms and associated control of hormonal secretion.)

By detailing how the large light response occurs in the amphioxus cells, Gomez and Nasi could relate their observations to the functional changes that may have occurred as the circadian receptors evolved and "eventually tailored their performance to the requirements of a reporter of day and night, rather than to a light sensor meant to mediate spatial vision." The light-sensing cells of amphioxus, they discovered, may be the "missing link" between the visual cells of invertebrates and the circadian receptors in our own eyes.


'/>"/>

Contact: Diana Kenney
dkenney@mbl.edu
508-289-7139
Marine Biological Laboratory
Source:Eurekalert  

Related biology news :

1. Engineers use droplet microfluidics to create glucose-sensing microbeads
2. First evidence of fish sensing geomagnetic fields from a Czech Christmas market
3. Nutrient-sensing enzymes key to starvation response and survival in newborn mammals
4. Eddies, not sunlight, spur annual bloom of tiny plants in North Atlantic
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Sensing the light, but not to see
(Date:4/17/2017)... NXT-ID, Inc. (NASDAQ: NXTD ) ("NXT-ID" or the "Company"), ... Report on Form 10-K on Thursday April 13, 2017 with the ... The ... section of the Company,s website at http://www.nxt-id.com  under "SEC Filings," ... 2016 Year Highlights: Acquisition of ...
(Date:4/11/2017)... , April 11, 2017 Crossmatch®, a ... authentication solutions, today announced that it has been ... Research Projects Activity (IARPA) to develop next-generation Presentation ... "Innovation has been a driving force ... program will allow us to innovate and develop ...
(Date:4/11/2017)... MELBOURNE, Florida , April 11, 2017 ... "Company"), a security technology company, announces the appointment of independent ... John Bendheim to its Board of Directors, furthering the ... ... behalf of NXT-ID, we look forward to their guidance and ...
Breaking Biology News(10 mins):
(Date:8/16/2017)... ... August 16, 2017 , ... ... and Electrospraying line of nanofiber and nanoparticle fabrication instruments from ... lab to fully automated pilot plants and equipment for industrial manufacturing. All ...
(Date:8/16/2017)... ... August 16, 2017 , ... ... and Drug Administration (FDA) inspection at our Dilworth, MN site. The inspection took ... This inspection was conducted as part of a routine Bioresearch Monitoring Program (BIMO) ...
(Date:8/15/2017)... ... August 15, 2017 , ... Kapstone Medical is proud to ... helping medical technology companies and inventors develop and safeguard their latest innovations. The ... firm with a portfolio of clients in the United States and around the world. ...
(Date:8/15/2017)... Wisconsin (PRWEB) , ... August 15, 2017 , ... ... a new family of 6” modular downlights designed to stay tightly sealed and ... including areas where damp and wet location listings just aren't enough, such as: ...
Breaking Biology Technology: