(Press-News.org) Just as raging hormones are part of the process of a child's maturation through the teen years to adulthood, juvenile hormones, a group of insect isoprenoids, play an important role as butterflies, fruit flies and mosquitoes transform their body structures as they molt from larva to pupa and then adults.
Unlike humans, in insects the juvenile hormone inhibits development of adult characteristics until the insects reach a proper stage. Juvenile hormones also play a prominent role in regulating reproductive maturation in adult insects and synthetic juvenile hormone mimics have been widely used as pesticides for mosquito controls.
Virginia Tech researchers have discovered an important step in the activation of juvenile hormone target genes. "Understanding the molecular details in the juvenile hormone signaling may lead to discovery of novel chemicals that target mosquitoes with more selectivity," said Jinsong Zhu, assistant professor of biochemistry with the Fralin Life Science Institute at Virginia Tech.
The research is reported in the early online edition of the Proceedings of the National Academy of Sciences the week of Dec. 27.
"The secretion of juvenile hormone is drastically reduced in the final larval stage, as a result of which the larva is transformed into a pupa. While an insect protein, Methoprene-tolerant (Met), has been postulated as the top candidate for juvenile hormone receptor, it remains unclear how this protein is activated by juvenile hormone," said Zhu.
He and his group believe that studying the hormone-regulated reproduction have a better chance of elucidating the molecular action of juvenile hormones. They discovered a protein partner for Met in the yellow fever mosquito Aedes aegypti. This protein, named FISC, forms a complex with Met when juvenile hormone is present. Binding of these two proteins to the regulatory regions of some juvenile hormone target genes is closely correlated with the expression levels of those target genes in the newly emerged adult mosquitoes. Reducing the protein levels of Met or FISC by genetic approaches leads to dampened expression of the juvenile hormone target genes, and decreased egg production after the female mosquitoes take a blood meal.
The study by Zhu's group clearly demonstrates that formation of Met-FISC complex is a critical step in juvenile hormone signaling pathway. Evidence presented in the Proceedings of the National Academy of Sciences paper also suggests that fruit flies use the same mechanism in mediating juvenile hormone responses during molting.
Zhu is now collaborating with Professor David Bevan's group in the biochemistry department to analyze the structure-function relationship of the Met protein.
INFORMATION:
The article, "A heterodimer of two bHLH-PAS proteins mediates the juvenile hormone-induced gene expression," is by Meng Li, graduate student; Edward A. Mead, postdoctoral associate; and Zhu. It will be available online at http://www.pnas.org/content/early/recent.
Dr. Zhu's website is http://www.biochem.vt.edu/faculty/kennelly.html?lname=Zhu&view=yes
Mechanisms of juvenile hormone action in insects could help fine tune pesticides
2010-12-28
ELSE PRESS RELEASES FROM THIS DATE:
Full woodland strawberry genome sequenced
2010-12-28
In a collaborative effort involving 74 researchers from 38 research institutes, scientists have produced the full genome of a wild strawberry plant. The research appeared today in Nature Genetics. Drs. Asaph Aharoni and Avital Adato of the Weizmann Institute's Plant Sciences Department were the sole Israeli scientists participating in the project, but they made a major contribution in mapping the genes and gene families responsible for the strawberry's flavor and aroma.
The woodland strawberry (Fragaria vesca) is closely related to garden-variety cultivated strawberry. ...
Standardized protocols would greatly enhance clinical and research potential of BTMs
2010-12-28
An expert working group of the International Osteoporosis Foundation (IOF) and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has released a new position paper which reviews the evidence of bone turnover markers (BTMs) in fracture risk prediction and monitoring of osteoporosis therapy. More importantly, it identifies research priorities and recommends that specific markers be used as reference analytes for BTMs in clinical and observational studies.
BTMs have been extensively studied in relation to fracture risk assessment and have ...
Parents' social problems affect their children -- even in birds
2010-12-28
It may come as a surprise to many that quails are able to distinguish one another, let alone that they form close relationships with other quails. Nevertheless, it has long been known that disruption of the birds' social environment causes them stress. A group within the UMR 6552 at the CNRS-Université de Rennes 1 in France has been studying the influence of adults on the behavioural development of their offspring. Together with scientists in Austria, they have now shown that changing the composition of groups of quails housed together causes the birds to behave more ...
When the black hole was born
2010-12-28
Most galaxies in the universe, including our own Milky Way, harbor super-massive black holes varying in mass from about one million to about 10 billion times the size of our sun. To find them, astronomers look for the enormous amount of radiation emitted by gas which falls into such objects during the times that the black holes are "active," i.e., accreting matter. This gas "infall" into massive black holes is believed to be the means by which black holes grow.
Now a team of astronomers from Tel Aviv University, including Prof. Hagai Hetzer and his research student Benny ...
Structure of key molecule in immune system provides clues for designing drugs
2010-12-28
PHILADELPHIA - A team from the University of Pennsylvania School of Medicine and Utrecht University has deciphered a key step in an evolutionarily old branch of the immune response. This system, called complement, comprises a network of proteins that "complement" the work of antibodies in destroying foreign invaders. It serves as a rapid defense mechanism in most species from primitive sponges to humans.
In a study published in the December 24 issue of Science, the groups of John Lambris, PhD, the Dr. Ralph and Sally Weaver Professor of Research Medicine at Penn, and ...
Comprehensive report on sudden oak death
2010-12-28
ALBANY, Calif.—Synthesizing more than 10 years of cooperative research on the exotic invasive, quarantine sudden oak death pathogen, the USDA Forest Service's Pacific Southwest Research Station (PSW) recently published "Sudden Oak Death and Phytophthora ramorum: A Summary of the Literature." This 181-page comprehensive report covers a wide range of topics, including a history of sudden oak death, identification and distribution of the disease, epidemiology and modeling, management and control, and economic and environmental impacts.
Compiled by retired U.S. Forest Service ...
ASPB applauds passage of America COMPETES reauthorization
2010-12-28
ROCKVILLE, Md. -- The American Society of Plant Biologists (ASPB) applauds Congressional reauthorization of the America COMPETES Act.
Originally enacted in 2007, the America Creating Opportunities to Meaningfully Promote Excellence in Technology, Education, and Science (COMPETES) Act underscored the nation's commitment to scientific research and science, technology, engineering, and mathematics education. Among other provisions, the 2007 and 2010 bills establish broad directions and set maximum funding levels for some of the nation's key science agencies, including the ...
Broken glass yields clues to climate change
2010-12-28
BOULDER--Clues to future climate may be found in the way that an ordinary drinking glass shatters.
A study appearing this week in Proceedings of the National Academy of Sciences finds that microscopic particles of dust, emitted into the atmosphere when dirt breaks apart, follow similar fragment patterns as broken glass and other brittle objects. The research, by National Center for Atmospheric Research (NCAR) scientist Jasper Kok, suggests there are several times more dust particles in the atmosphere than previously believed, since shattered dirt appears to produce an ...
GOES-13 satellite captures powerful snowmaker leaving New England
2010-12-28
Snows are finally winding down in New England today, Dec. 27, as a powerful low pressure system brought blizzard conditions from northern New Jersey to Maine over Christmas weekend. The GOES-13 satellite captured an image of the low's center off the Massachusetts coast and saw the snowfall left behind.
The Geostationary Operational Environmental Satellite called GOES-13 captured the visible image. GOES satellites are operated by the National Oceanic and Atmospheric Administration, and NASA's GOES Project, located at NASA's Goddard Space Flight Center, Greenbelt, Md. creates ...
OC Spinal Decompression Launches New Physical Therapy Website
2010-12-28
Irvine Family Health Center Spinal Decompression
announced today that they have launched a new website at OCSpinalDecompression.com. The website provides information for sufferers of neck pain, lower back pain, degenerative disc disease, pinched sciatic nerve, bulging discs, herniated disc pain, and more. The website is designed to promote the physical therapy office located in Orange County, California.
The website not only offers information related to many neck and back ailments, but it also discusses a new treatment called the DRX9000 Spinal Decompression unit. ...