Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic differences in termite castes may lead to better control

21.10.2003


Termite colonies, such as this one collected on the Purdue campus, are helping researchers like Michael Scharf develop ways to control the pest. Scharf is an entomology research professor and director of the Purdue Industrial Affiliates Program in the Center for Urban and Industrial Pest Management. (Purdue Agricultural Communications photo/Tom Campbell)


Learning the molecular processes that cause termite larvae to grow into workers, soldiers or reproductive adults may lead to new methods to decimate colonies of the wood-eaters, according to Purdue University researchers.

The scientists identified 25 genes that provide some of the first information concerning the differentiation of the insects based on the role they play within a colony. The study, published in this month’s issue of the journal Genome Biology (http://genomebiology.com/2003/4/10/R62), shows that the level at which some of the newly discovered genes are expressed differs depending on which adult form the termite becomes.

"Many of the genes we found are involved in muscle function," said Michael Scharf, entomology research professor and lead author of the study. "Most of these muscle proteins are expressed in the soldiers and not the workers. The soldiers have big heads and jaws, so they require more muscle in the head to drive those jaws.



"But soldiers don’t have wings, so they don’t have flight muscles as are found in the developing nymphs, which become winged reproductive adults."

Though possibly hundreds of termite species exist around the world that are different sizes and live in different types of colonies, they all have similarities. They all eat wood or woody plants high in cellulose. They are very social and form monogamous relationships in which a new king and queen fly away from the original colony to form a new one. Termite larvae can become a member of any of three castes – soldiers, workers and the nymphs that develop into alates, or reproductively mature males and females.

The soldiers guard the colony but can’t reproduce, fly or feed themselves. Workers feed the other termites, tend the larvae and young insects, and dig tunnels. The alates can fly and reproduce.

"Termites have a hormone, called juvenile hormone, that is very important to insects during their development," said Scharf, also director of the Purdue Industrial Affiliates Program in the Center for Urban and Industrial Pest Management. "When they are immature they have this hormone, but when it’s gone they molt for a final time and become adults. In termites, the adults are the reproductive individuals that replenish the colony with new members."

Scharf and his team found that if they treated worker termites with juvenile hormone, they became soldiers. They also found that in normal colonies some nymphs begin to develop eyes, wings and reproductive anatomy, but also can regress into workers by molting backwards and losing their eyes, wing pads and their reproductive characteristics.

"If we could modify proteins in termites to change workers into helpless soldiers, then we could make 75 percent of the colony soldiers," he said. "That would be pretty lethal to the termites but have minimal environmental impact."

Since the alates and the soldiers can’t feed themselves or dig tunnels, and the workers and soldiers can’t reproduce, the termites would die off fairly quickly, Scharf said.

The researchers found that workers have high levels of four genes that produce enzymes for breaking down cellulose into digestible sugars. Cellulose is the substance that makes up the structure of plants; the enzymes that break down the cellulose are called cellulases. Two of these four genes produce cellulases in the termites. The other two are from microbes in the termites’ digestive system. These bacteria aid in metabolizing the food.

The Purdue scientists also found a number of termite genes related to ones found in the common research insect, Drosophila. Some of these genes also may be similar, or homologous, to development genes in other animals.

Mutation of one of these related genes causes Drosophila, or fruit flies, to have two lower halves and no head. The related gene in termites is found at higher levels in the soldiers, Scharf said. This mutation, fatal in fruit flies, may explain why soldier termites’ heads and bodies are almost the same size.

"Our research is teaching us about termite biology and development – how they diverge into their different forms, create a colony and exploit their environment, which quite often could be somebody’s house," Scharf said. "What we have learned so far is just the tip of the iceberg."

Termites found in many areas of the United States are Reticulitermes flavipes, a species of lower termites. Lower termites are subterranean, meaning they live below ground and in wood. These are about the size of a ballpoint pen tip. Higher termites, which aren’t found in the continental United States, are much bigger and build large mounds above the ground.

Termites are often mistaken for ants, however, there are some easy ways to tell the difference. Termites have straight antenna and an oval or oblong body, and those with wings have two pairs of equal length. Ants have antenna that bend at a 90-degree angle, a pinched-in abdomen and those with wings have front wings that are much longer than the back pair.

According to experts, the first known termites evolved about 100 million years ago when dinosaurs existed. They came from the same ancestors as wood-dwelling cockroaches.

The other researchers involved with this study were research scientist Dancia Wu-Scharf, assistant professor Barry Pittendrigh and professor Gary Bennett, all of the Purdue Department of Entomology.

The Center for Urban and Industrial Pest Management Industrial Affiliates Program and the Office of the Vice President of Agricultural Research provided funding for this study.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu

Source: Michael Scharf, (765) 494-6314, mike_scharf@entm.purdue.edu

Susan A. Steeves | Purdue News
Further information:
http://genomebiology.com/2003/4/10/R62
http://news.uns.purdue.edu/UNS/html4ever/031020.Scharf.termites.html
http://www.entm.purdue.edu/

More articles from Life Sciences:

nachricht Polymers Based on Boron?
18.01.2018 | Julius-Maximilians-Universität Würzburg

nachricht Bioengineered soft microfibers improve T-cell production
18.01.2018 | Columbia University School of Engineering and Applied Science

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Polymers Based on Boron?

18.01.2018 | Life Sciences

Bioengineered soft microfibers improve T-cell production

18.01.2018 | Life Sciences

World’s oldest known oxygen oasis discovered

18.01.2018 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>