Navigation Links
UC Santa Barbara researchers discover genetic link between visual pathways of hydras and humans

(Santa Barbara, Calif.) What good is half an eye? Evolutionary biologists studying the origins of vision get that question a lot, and new research out of UC Santa Barbara points to a possible answer. Findings appearing today in the journal BMC Biology indicate that, even in the absence of eyes altogether, some creatures display a light-sensitivity that uses the same visual pathway that allows humans to see.

Todd Oakley, professor in UCSB's Department of Ecology, Evolution, and Marine Biology, co-authored the paper about the genetic behavior of hydra, a freshwater polyp. Along with jellyfish, sea anemones, and corals, hydra are part of the animal family Cnidaria, who use stinging cells, or cnidocytes, to catch prey. Hydra tentacles contain barbed, poison-containing cnidocytes that they use to stun animals, such as water fleas and plankton, before eating them alive. They also use their cnidocytes for self-defense and locomotion.

The research conducted at UCSB revealed that light, or the lack thereof, has a direct effect on hydras' propensity to fire their stinging cells a discovery Oakley said "tells us something completely new about the biology of these animals, and we think this could extend to other cnidarians."

"Hydra stinging cells were already known to be touch sensitive and taste sensitive, but no one had ever thought before to look for light sensitivity probably because they don't have eyes," Oakley said. "We're the first to have found that. And we found not only that light-sensitivity genes are expressed near hydra stinging cells, but that under different light conditions, these cells have different propensities to be fired."

Studying the hydra in both bright and dim conditions, the researchers discovered that bright light actually inhibits the firing of the stinging cells possibly because their prey are more active at dusk and after sunset, said Oakley. He suggested that light could be acting as "a daily, rhythmic cue" that tells hydra when, and when not, to sting.

The research found that the light-sensitive protein opsin in sensory cells regulates the firing of the hydra's harpoon-like cnidocytes. These same cells are found in the mechanisms hydra use to grasp prey, and to summersault through the water.

The linking of opsin to the stinging cells helps explain how hydra can respond to light despite the absence of eyes, the scientists said, because the sensory neurons also contain the ion channels and additional proteins required for phototransduction the process by which light is converted to electric signals. Phototransduction in humans occurs in the retina.

"I wouldn't call this vision, because as far as we know the hydra are not processing information beyond what's light and what's dark, and vision is much more complicated than that. But these genes that we're studying are the keystones of vision," Oakley said. "For us, as evolutionists, the message is that photoreception can do other things besides just facilitate vision. It can do unexpected things. What good is half an eye? Even without eyes there are other functions for light sensitivity that we may not be thinking of."


Contact: Shelly Leachman
University of California - Santa Barbara

Related biology news :

1. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
2. UC Santa Barbara researchers new study may lead to MRIs on a nanoscale
3. University of California Santa Barbara study reveals how gas, temperature controlled bacterial response to Deepwater Horizon spill
4. Argentinas Santa Fe government reducing lead ammunition for sports hunters
5. New data published in Nature Genetics demonstrate that tiny LNA-based compounds developed by Santaris Pharma A/S inhibit entire disease-associated microRNA families
6. Marine Protected Areas Federal Advisory Committee meets Nov. 2-3 in Santa Barbara
7. Santa Fe homeowners weigh in on landscape preferences
8. Researchers study effect of yuma desalting plant on Cienega de Santa Clara
9. CNIC and Banco Santander set up research project on early cardiovascular risk factors
10. UC Santa Barbara and Burnham Institute for Medical Research announce director
11. Rudolfs kin more than just Santas ride
Post Your Comments:
Related Image:
UC Santa Barbara researchers discover genetic link between visual pathways of hydras and humans
(Date:11/16/2015)... Calif. , Nov 16, 2015  Synaptics ... of human interface solutions, today announced expansion of ... TouchView ™ touch controller and display driver ... revolution of smartphones. These new TDDI products add ... TD4100 (HD resolution), TD4302 (WQHD resolution), and TD4322 ...
(Date:11/10/2015)... 10, 2015  In this report, the ... of product, type, application, disease indication, and ... report are consumables, services, software. The type ... biomarkers, efficacy biomarkers, and validation biomarkers. The ... diagnostics development, drug discovery and development, personalized ...
(Date:11/2/2015)... 2, 2015  SRI International has been awarded a ... development services to the National Cancer Institute (NCI) PREVENT ... scientific expertise, modern testing and support facilities, and analytical ... and toxicology studies to evaluate potential cancer prevention drugs. ... PREVENT Cancer Drug Development Program is an NCI-supported pipeline ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... , Nov. 24, 2015  Asia-Pacific (APAC) holds ... organisation (CRO) market. The trend of outsourcing to ... margins but higher volume share for the region ... scale, however, margins in the CRO industry will ... Market ( ), finds that the ...
(Date:11/24/2015)... , Nov. 24, 2015 Cepheid (NASDAQ: ... be speaking at the following conference, and invited investors ... York, NY      Tuesday, December 1, 2015 at ... York, NY      Tuesday, December 1, 2015 at ... Healthcare Conference, New York, NY ...
(Date:11/24/2015)... 2015 /CNW/ - iCo Therapeutics ("iCo" or "the Company") ... for the quarter ended September 30, 2015. Amounts, ... and presented under International Financial Reporting Standards ("IFRS"). ... said Andrew Rae , President & CEO ... not only value enriching for this clinical program, ...
(Date:11/24/2015)... , ... November 24, 2015 , ... ... of the year and one of the premier annual events for pharmaceutical manufacturing: ... from 8–11 November 2015, where ISPE hosted the largest number of attendees in ...
Breaking Biology Technology: