Navigation Links
Brainy genes, not brawn, key to success on mussel beach
Date:10/9/2008

It's hard being a mussel: you have to worry about hungry starfish and even hungrier humans, not to mention an environment that can change your body temperature 50 degrees Fahrenheit in just a few hours.

"It's one of the most variable habitats on Earth," said USC biologist Andrew Gracey. "Mussels can spend part of the day bathed in cool Pacific seawater and the other part baked under the California sun."

Gracey led the first real-time molecular sampling of mussels in their natural habitat, the results of which appear online Oct. 9 in the journal Current Biology.

The researchers found that the hardy mollusks alternate between expressing genes associated with eating and genes associated with growing.

Scientists have thought that mussels survive their harsh home on the rocks by just being tough, but this study suggests a more sophisticated strategy.

"They spend part of the day respiring, and doing metabolic processes, and then the other part of the day switching to cell division," Gracey explained.

Because their environment is so unpredictableat low tide mussels could scorch on a sunny day and get soaked on a stormy onethese regular cycles were unexpected.

"To be honest, I first thought they'd be wasting their time to be constantly switching on this gene and switching off that gene," Gracey said.

The scientists also found that as the environment became harsherlike higher up the rocksthe oscillations in gene expression became more pronounced.

Mussels use genes to weather the heat

In addition to cyclic expression, the study found that mussels use two sets of genes to respond to heat stresssometimes reacting to temperature changes in seconds.

"Day-in, day-out, they switch on a particular set of genes associated with routine heat stress, but when the day got very hot we saw this other battery of genes dealing with really extreme temperatures," Gracey said.

The first set of genes triggers the formation of chaperones that prevent proteins from unraveling, while the second set creates proteins that shepherd damaged material away.

This could have implications for climate change and how a key species like musselsfundamental to the ecology of inter-tidal rocky zoneswould adapt to a hotter world.

In addition, there are implications for understanding sudden summer mortality syndrome, a mysterious die-off that can devastate oyster farms, and which is believed to be linked to a stress event like heat.

Gene oscillation as survival strategy

Expressing genes in waves appears to be a survival strategy, one that has been seen in lab experiments involving yeast.

"There are certain physiological processes that are fairly incompatible, like respiration and cell division," Gracey explained.

Respiration creates free radicals, and if an organism undergoes cell division at the same time, those free radicals could damage DNA. (This is partly why antioxidants in green tea and pomegranates are popular these days, since they remove free radicals.)

By keeping respiration and cell division separate, mussels can decrease the chances of such cell damagean advantage in such extreme conditions.

What controls the cycles?

In humans, the circadian rhythm is also a cycle that involves waves of gene expression, but unlike the mussel cycles, it has consistent intervals regulated by light.

"Periods are typically constant, and typically they're following something related to a 24-hour cycle," Gracey noted. "Our data doesn't conform to that."

It's not yet clear what is driving the cycles in mussels. It could be temperature, how much time is spent out of the water, or the opportunity to feedbut it's hard to pin down a single variable.

(A new grant from the National Science Foundation will help Gracey and colleagues tackle that question through lab simulations.)

Study methods

The scientists collected genetic material every three to four hours over three days, sampling mussel beds just south of the Monterey Bay Aquarium in California. They also installed "robo-mussels"chips sealed in siliconto record body temperature.

Back in the lab, the DNA was sequenced and bound to 10,000 points on a "gene chip," or DNA microarray.

They then extracted RNAthe messenger that commands expression of a certain genefrom the samples at the 20 successive time points.

RNA from two consecutive points was then converted to DNA, which was labeled with two different dyes. These two types of DNA were then allowed to bind with different points on the microarray, which correspond to different points on the mussel genome.

Thanks to the dyes, the scientists could then observe which sample from which time point bound relatively more to a specific part of the mussel genome.

When this was determined, the functions of those genes that were expressed more at that point in time could be inferred based on their similarity to genes in public databases.


'/>"/>

Contact: Terah DeJong
tdejong@usc.edu
213-740-8606
University of Southern California
Source:Eurekalert  

Related biology news :

1. NIHs Genes, Environment and Health Initiative adds 6 studies
2. Location, location, location important for genes, too
3. Researchers report the cloning of a key group of human genes, the protein kinases
4. Genes, Environment and Health Initiative invests in genetic studies, environmental monitoring
5. Gene regulation, not just genes, is what sets humans apart
6. University success at national engineering awards
7. Army can boost mission success by better managing
8. HPV DNA test identifies cervical pre-cancerous disease in developing countries with 90% success rate
9. Gap junction protein vital to successful pregnancy, researchers find
10. Successful series of measurements in Arctic sea ice
11. Dont count on long-term success in climate policy, warns paper in Decision Analysis
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Brainy genes, not brawn, key to success on mussel beach
(Date:2/8/2016)... February 8, 2016 Worldcore ... which presents innovation for clients, comfort and unbeatable ... VoiceKey. --> Worldcore is the ... for clients, comfort and unbeatable security, with a ... Worldcore is the first EU-regulated ...
(Date:2/3/2016)... , February 4, 2016 --> ... to SEK 1,351.5 M (105.0), up 1,187% compared with fourth quarter of ... amounted to SEK 517.6 M (loss: 30.0). Earnings per share ... activities was SEK 537.4 M (neg: 74.7). , ... , Revenues amounted to SEK 2,900.5 M (233.6), up 1,142% compared with ...
(Date:2/3/2016)... http://www.researchandmarkets.com/research/d8zjcd/emotion_detection ) ... "Emotion Detection and Recognition Market by Technology ... Tools (Facial Expression, Voice Recognition and Others), ... Global forecast to 2020" report to ... ) has announced the addition of the ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... FL (PRWEB) , ... February 10, 2016 , ... ... in regenerative medicine, has announced a new agreement with Singapore-based Global Stem Cells ... physicians from the Philippines, Thailand and Singapore in the latest adipose and bone ...
(Date:2/9/2016)... ... 2016 , ... Date and time: March 1, 2016, 5:30 ... Biotechnology Center of Bucks County, 3805 Old Easton Road, Doylestown, PA 18902. , ... an open house for participants to learn about a new Master of Biomedical ...
(Date:2/9/2016)... ... February 09, 2016 , ... The publishing industry has ... publishing is one of the popular publication models that has received wider acknowledgement ... and 3000+ International Conferences across the globe, OMICS International is all ...
(Date:2/9/2016)... 9, 2016 Three-Year Initiative Supports Next ... Take Part in Life-Changing Camp Experiences ... to positively affect the lives of children born with rare diseases, ... SHPG ) is announcing a new initiative designed to positively ... as the future of rare disease care. --> To ...
Breaking Biology Technology: