(Press-News.org) In the absence of eyes, the fresh water polyp, Hydra magnipapillata, nevertheless reacts to light. They are diurnal, hunting during the day, and are known to move, looping end over end, or contract, in response to light. New research published in BioMed Central's open access journal BMC Biology shows that stinging cells (cnidocytes) in hydra tentacles, which the animals use for self protection and to catch prey, are linked via a simple nervous system to primitive light responsive cells that co-ordinate the animals' feeding behavior.
Hydra are members of a family of radially symmetric animals (Cnidaria), all of which use specialized cnidocytes to catch prey. This family also includes well-known creatures such as jellyfish and corals, which, like other cnidarians, have the simple design of a mouth surrounded by tentacles. Hydra tentacles contain barbed, poison containing cnidocytes that they use to stun animals like the water flea, Daphnia, before eating them alive, and to protect themselves from attack by other animals.
Researchers from the University of California lead by Dr David Plachetzki have discovered that the light sensitive protein opsin found in sensory cells is able to regulate the firing of harpoon-like cnidocytes. These light sensitive neurons are found integrated into arsenals that include the stinging cnidocytes as well as desmoneme cnidocytes, used to grasp prey, and sticky isorhiza, which help the hydra to summersault at 10cm a day.
The linking of opsin to cnidocytes explains how hydra are able to respond to light even though they do not have eyes. Dr Plachetzki described how other proteins necessary for phototransduction are also present in the sensory cells. "Not only did we find opsin in the sensory neurons that connect to cnidocytes in the hydra, but we also found other components of phototransduction in these cells. These included cyclic nucleotide gated ion channels (CNG) required to transfer the signal and a hydra version of arrestin, which wipes the phototransduction slate clean for a second signal."
Dr Plachetzki continued, "We were also able to demonstrate that cnidocyte firing itself is effected by the light environment and that these effects are reversed when components of the phototransduction cascade are turned off."
Cnidarians have been around for over 600 million years. However the hydra's simple approach to using light, to aid survival and increase their chances of catching prey, uses the same visual pathway as humans and hints at a common ancestor.
INFORMATION:
Notes to Editors
1. Cnidocyte discharge is regulated by light and opsin-mediated phototransduction
David C Plachetzki, Caitlin R Fong and Todd H Oakley
BMC Biology (in press)
Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.
Article citation and URL available on request on the day of publication.
2. BMC Biology is the flagship biology journal of the BMC series, publishing open-access, peer-reviewed research and methodology articles of special importance and broad interest in any area of biology, as well as reviews, opinion pieces, comment and Q&As on topics of special or topical interest.
3. BioMed Central (http://www.biomedcentral.com/) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.
Seeing without eyes: Hydra stinging cells respond to light
2012-03-05
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Does your mother know?
2012-03-05
Do your parents know where you are at night? According to 36 per cent of 15 year old boys and nearly a quarter of 15 year old girls the answer to that question, at least once a month, is no.
This is the finding from Understanding Society, a long term study of 40,000 UK households, which asked more than 2,000 10-15 year olds how frequently they stayed out past 9.00pm without their parents knowing where they were. The study, which is funded by the Economic and Social Research Council (ESRC), also found that staying out late without telling your parents is unrelated to ...
Escaping parasites and pathogens
2012-03-05
In nature, how do host species survive parasite attacks? This has not been well understood, until now. A new mathematical model shows that when a host and its parasite each have multiple traits governing their interaction, the host has a unique evolutionary advantage that helps it survive.
The results are important because they might help explain how humans as well as plants and animals evolve to withstand parasite onslaught.
The research, reported in the March 4 online edition of Nature, was supported by the National Institute for Mathematical and Biological Synthesis ...
X-rays reveal how soil bacteria carry out surprising chemistry
2012-03-05
Researchers working at the U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory have used powerful X-rays to help decipher how certain natural antibiotics defy a longstanding set of chemical rules – a mechanism that has baffled organic chemists for decades.
Their result, reported today in Nature, details how five carbon atoms and one oxygen atom in the structure of lasalocid, a natural antibiotic produced by bacteria in soil, can link into a six-membered ring through an energetically unfavorable chemical reaction. Unlocking this chemical pathway could ...
A new direction for game controllers
2012-03-05
SALT LAKE CITY – University of Utah engineers designed a new kind of video game controller that not only vibrates like existing devices, but pulls and stretches the thumb tips in different directions to simulate the tug of a fishing line, the recoil of a gun or the feeling of ocean waves.
"I'm hoping we can get this into production when the next game consoles come out in a couple of years," says William Provancher, an associate professor of mechanical engineering who is in Vancouver, British Columbia, demonstrating the new game controller with his students March 5-7.
They ...
New Michigan Cash for Clunkers Program
2012-03-05
Details about Michigan "Cash for Clunkers" payout program have been announced. Under the NEW "Cash for Clunkers Michigan" or "Michigan Clunkers" program, consumers will be guaranteed a minimum of $2,500 trade-in towards any nicer, newer vehicle from a participating new car dealer when they trade in their old vehicle and purchase a qualifying vehicle.
In order to be eligible for the program, the trade-in passenger vehicle must be in drivable condition and be continuously insured and registered to the same owner for the full year before the ...
Kids' abnormal breathing during sleep linked to increased risk for behavioral difficulties
2012-03-05
VIDEO:
Karen Bonuck, Ph.D., discusses her new research showing that young children with sleep-disordered breathing are prone to developing behavioral difficulties such as hyperactivity and aggressiveness, as well as emotional symptoms...
Click here for more information.
March 5, 2012 — (BRONX, NY) — A study of more than 11,000 children followed for over six years has found that young children with sleep-disordered breathing are prone to developing behavioral difficulties such ...
Prominence Treatment Center Offers Non 12-Step Treatment Programs for Alcohol and Drug Addiction
2012-03-05
Due to the ongoing coverage of celebrity deaths that involve drug or alcohol abuse, many of those that are struggling with their own addictions have begun exploring what options may be available to them. This first step is always daunting though, and many individuals may be uncomfortable joining a cookie-cutter program that may not exactly fit their own needs and concerns. This is why Non 12 step rehab center, Prominence Treatment Center, is now offering its services to anyone that would like a unique and personalized strategy to beat their own addiction.
Addiction can ...
Discovery of primary exhalative hydrothermal dolostone in the Santanghu area, Xinjiang
2012-03-05
The origin of dolomite has been hotly debated. There is still a lack of petrological evidence and theoretical support for the formation of primary dolomite in geological history because dolomite cannot be synthesized under normal laboratory conditions. Wright (2004) experimented with Kulong lake water under normal surface temperature and pressure conditions to precipitate dolomites. His study offered experimental petrological evidence for primary dolomite formation. However, examples of ancient primary dolomites are rare. A research group lead by Professor Liu at Northwestern ...
Working models for the gravitational field of Phobos
2012-03-05
Phobos is the larger and closer of the two natural satellites of Mars. Despite decades of Martian exploration, we still know very little about Phobos. Many fundamental properties of this small potato-shaped body stay vague, for example, its gravitational field. SHI Xian and coauthors from Shanghai Astronomical Observatory and Technical University Berlin recently updated working models for the gravitational field of Phobos. Their work, entitled "Working models for the gravitational field of Phobos", was published in SCIENCE CHINA Physics, Mechanics & Astronomy, 2012, Vol ...
Did You Know You Need Workers' Compensation Coverage if You Have a Nanny or Other Domestic Working for You?
2012-03-05
Pursuant to the New York State Workers' Compensation Law if you have a nanny who works for you for more than 40 hours a week you must have workers' compensation coverage for that person. That would include somebody who is a home attendant or a companion for an elderly parent or relative. Your homeowner's insurance policy does not cover the nanny or other domestic. You need a separate workers' compensation policy obtained from an insurance company such as the New York State Insurance Fund or other private carrier that writes workers' compensation coverage in New York.
If ...