Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene needed for butterfly transformation also key for insects like grasshoppers

28.04.2006
It is a marvel of nature that a creature such as a caterpillar changes into something quite different, a butterfly. Contrast that with a grasshopper, which looks largely the same from the time it hatches through its adult stage.

New University of Washington research shows that a regulatory gene named broad, known to be necessary for development of insects that undergo complete metamorphosis, also is key for the maturation of insects that have incomplete metamorphosis. The work appears to present the first molecular evidence that the nymphal stage in lower insects is equivalent to the pupal, or chrysalis, stage of advanced insects such as butterflies.


An insect in the fourth nymphal stage of development (Figure A) progresses normally to the fifth development stage (Figure B). However, if a gene called broad is suppressed in the first half of the fourth stage, the nymph moves to the fifth stage but keeps pigmentation patterns and other characteristics of the fourth stage (Figure C). Credit: Photo credit: Deniz Erezyilmaz

Metamorphosis evolved in insects about 300 million years ago from ancestors of direct-developing insects such as grasshoppers. Biologists know the broad gene regulates metamorphosis in flies and moths and is found only at the transition between their larval and pupal stages. To understand how metamorphosis evolved in insects, the UW researchers examined how the broad gene functions in direct-developing insects, which don’t have a pupal stage.

"We found that it is expressed throughout the nymphal stages, and that it is also required for change," said Deniz Erezyilmaz, a UW biology research associate. "So it looks like metamorphosis evolved in insects by restricting the expression of the broad gene to a short but intense period of change at the transition from larva to pupa."

Normally an insect like the grasshopper that does not undergo complete metamorphosis goes through subtle physical changes during each of its nymphal stages as it progresses to adulthood. If broad is suppressed, the nymph simply repeats the appearance from its previous phase but continues to show normal growth, Erezyilmaz said. The organism eventually becomes an adult, but adult structures such as the wings are severely undersized.

"Broad is not required to transform into the adult, but it is needed to move through the series of nymphal stages," she said. "An insect should look different from one stage to the next, but if you remove broad it doesn’t."

Erezyilmaz is the lead author of a paper describing the findings, published online Tuesday in the Proceedings of the National Academy of Sciences. The work was done in the UW laboratories of biology professors James Truman and Lynn Riddiford, who are co-authors of the paper, and was underwritten by grants from the National Science Foundation and the National Institutes of Health.

Genes regulate how an organism grows and changes physically as it develops. The broad gene encodes a protein that attaches itself to a specific region of a DNA chain and controls which other genes will be copied. The researchers suspect that broad must be present for the physical changes contained in those areas of DNA to be expressed. Suppressing broad prevents the changes from occurring.

"Humans don’t have the broad gene, but if they did and you suppressed it you’d have a baby that might grow to 6 feet tall but would still have the body proportions of a baby," Truman said. "It would still have the large head and the stubby legs."

A substance called juvenile hormone is present at each step of nymph development in insects that do not experience complete metamorphosis, and the researchers found that juvenile hormone correlates with the expression of the broad gene during the nymphal stage. Juvenile hormone disappears in the last nymphal stage and the broad gene is no longer expressed, allowing the insect to make the final transition to adulthood.

"This is the first time that anyone has seen the broad gene appear in the development of insects having incomplete metamorphosis," said Riddiford. "It appears in the late embryonic stage and stays throughout nymphal life, then disappears when the insect transforms to an adult."

Vince Stricherz | EurekAlert!
Further information:
http://www.washington.edu

More articles from Life Sciences:

nachricht Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>