Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists unraveling lice genome to halt blood-sucking pest

04.11.2003


Research aimed at understanding how lice feed off humans may lead to new methods to control the blood-sucking pest that can transmit fatal diseases.


Genetic research conducted by Purdue researcher Barry Pittendrigh may "ultimately lead to some real long-term benefits for Indiana and throughout the world," according to the assistant professor of entomology. Purdue scientists have identified the first gene in lice that kills bacteria that threatens the insect. (Purdue Agricultural Communications photo/Tom Campbell)



In the November issue of the journal Insect Biochemistry & Molecular Biology, Purdue and Harvard university researchers report finding lice genes that control the breakdown of their human blood meal into energy and waste. They also identified the first gene in lice that may impact the insects’ ability to fight off bacterial infections. The study is currently on the journal’s Web site.

"This research eventually may lead to long-term human health benefits for people throughout the world," said Barry Pittendrigh, assistant professor of entomology and senior author of the study. "We need to develop novel strategies for controlling these pests. Body lice raise significant health concerns in developing countries, and head lice afflict children in North America and elsewhere."


Previously only three genes for body and head lice had been described, said Pittendrigh, who also is associated with the Indiana Center for Insect Genomics (ICIG). The researchers screened 1,152 clones of lice genes.

"We found a defensin gene, which is most likely involved with the insect’s immune response to bacterial infections, Pittendrigh said. "Additionally, we found several genes that make proteins, which may cause allergic responses in humans.

"If you have no gene sequences, it’s very difficult to do the next level of experiments to understand interactions between lice and the host."

The scientists used frozen, ground up, engorged body lice to identify genes expressed in lice. Pittendrigh said current knowledge of the insects indicates that body lice and head lice are genetically similar.

The grain-of-rice sized adult body louse is six-legged and usually yellow to white in color. They are found most often on people who don’t practice good hygiene. The lice hide and lay eggs on people’s clothing when not feeding daily on blood.

Head lice are virtually indistinguishable from body lice, but they use hook-like claws to attach themselves to hair shafts on the head. A third type of louse that feeds on humans is the pubic louse.

Body lice inject saliva into the infested person, often causing itching and usually a rash or red bumps on the skin. Scratching the rash can cause infected sores. In certain areas of the world, body lice may transmit fatal diseases such as louse-borne typhus.

Pittendrigh and the lead researcher on the project, Joao Pedra, said understanding lice at the genetic level is critical to developing new methods to prevent infestation. It’s especially important to know the genes and proteins involved in digesting their blood meal and also those genes that provide disease and pesticide resistance.

"This study is the first step in understanding the molecular biology of digestive processes of a medically important pest insect," said Pedra, entomology graduate research assistant.

Other genes Pittendrigh and his team identified are involved in detoxification, iron metabolism and the breakdown of protein within cells.

According to the Centers for Disease Control and Prevention, body lice rarely are found in the United States and other western nations except sometimes on people who don’t have access to bathing facilities. However, they are a major problem in war zones, refugee camps and in areas of natural disasters – anywhere that lacks sanitary conditions and is crowded. These areas also are where outbreaks of lice-borne diseases, such as typhus, relapsing fever and trench fever, are most likely to occur.

Head lice are still a problem throughout the world and are usually found on children rather than adults. They also more frequently infest Caucasians than other races, and more often women than men. Usually only a dozen or fewer active adult head lice are on one person at a time, according to Richard Pollack, of the Harvard University School of Public Health, Department of Immunology and Infectious Diseases and a study co-author.

He said all three types of human lice sometimes can be found on facial hair, and they can all be treated with insecticides, including shampoos containing pyrethroids.

Other species of lice attack animals, such as dogs and cats, but house pets don’t maintain or transmit human lice.

"Current methods of controlling lice are fine, but understanding the molecular biology of lice may lead to novel pest control strategies that may be more cost-effective and cause fewer concerns," Pittendrigh said. "Ten or 15 years from now it would be wonderful if a vaccine is developed to control head lice, resulting in no more head lice problems in schools."

The other Purdue researchers involved in this study are: Amanda Brandt and Hong-Mei Li, of the Department of Entomology; Rick Westerman, of the Purdue Computational Genomics Center (PCGC); Jeanne Romero-Severson, of the PCGC, ICIG and assistant professor in the Department of Forestry and Natural Resources; Larry Murdock, of the Purdue Molecular Plant Resistance and Nematode Team and professor in the Department of Entomology.

Indiana’s 21st Century Research and Technology Fund and the Indiana Center for Insect Genomics provided funding for this research.

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

Source: Barry Pittendrigh, (765) 494-0535, barry_Pittendrigh@entm.purdue.edu

Susan A. Steeves | Purdue News
Further information:
http://news.uns.purdue.edu/hp/Pittendrigh.lice.html

More articles from Life Sciences:

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>