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 Seeing on the Quick: New Insights into Active Vision in the Brain
15.08.2018 | Eberhard Karls Universität Tübingen

nachricht New Approach to Treating Chronic Itch
15.08.2018 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Unraveling the nature of 'whistlers' from space in the lab

15.08.2018 | Physics and Astronomy

Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide

15.08.2018 | Earth Sciences

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>