Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Size doesn’t matter

04.07.2005


Rockefeller scientists show that microRNAs play an essential role in the development of the fruit fly

In a story reminiscent of David and Goliath, new research from Rockefeller University shows that sometimes the smallest molecules can be the most powerful. In the July 1 issue of Cell, Ulrike Gaul, Ph.D., and colleagues report that microRNAs serve very important, and very specific, functions during the early development of the fruit fly.

First discovered a few years ago, microRNAs are short strings of RNA that are made in large amounts in every cell from plant to humans. Biochemists, including co-author Thomas Tuschl, Ph.D., found that microRNAs bind to messenger RNAs, which are the blueprints for proteins, and either target them for destruction or inhibit them from making proteins. "There was a lot of beautiful biochemistry showing how microRNAs are made and processed," says Gaul, head of the Laboratory for Developmental Neurogenetics. "But we didn’t really know how important they are for the development of an organism and its function."



To solve this question, Gaul and colleagues systematically blocked each of the 46 known microRNAs that are active during early development of the fruit fly. This is difficult to do by traditional genetic means, so they inject young fly embryos with short strings of RNA that bind to the microRNAs and prevent them from finding their target messenger RNAs. The researchers found that over half of the microRNAs were not only essential for development, but also affected it in very specific ways. "Many of the fundamental processes in development are regulated by microRNAs," Gaul says, "including body patterning, morphogenesis, nervous system and muscle development. In particular, though, we found that cell survival relies very heavily on them."

Cell death in development is not uncommon. The developing embryo makes an overabundance of many cell types, like nerve cells, which it then removes later in a process of fine-tuning. In fact, the genes in flies that carry out a cell’s death sentence, Hid, Grim and Reaper, are expressed in many healthy cells, poised to do their job at a moment’s notice.

Gaul’s new research shows that it is microRNAs that stand between a cell’s survival and its death at the hands of Hid, Grim and Reaper. The microRNAs bind to the messenger RNA of the death genes and prevent their proteins from being made. But when the microRNAs are blocked, Hid, Grim and Reaper proteins are produced, causing massive cell death and killing the fly embryo.

The microRNAs that block cell death all belong to the largest microRNA family in the fruit fly. The family is made up of 13 members, which are identical in sequence at one end but different at the other. There has been some debate on whether differences at this end are important, but Gaul’s research now shows that they are central for helping the microRNAs find the right targets. "Our findings show that while similar defects are seen when the different family members are blocked, they are not identical," Gaul says. "And we find that different family members interact differently with the three death genes."

Deciding between life and death is only one of many split-second decisions that a cell may have to make. By regulating which messenger RNAs are used to make protein, microRNAs can help cells react to an event without the nucleus being involved. For example, the ending of a nerve cell can be very far away from its nucleus. Localizing and regulating messenger RNAs at the nerve endings enables the nerves to react very fast to an incoming signal, instead of every signal being transmitted to the nucleus and back.

Gaul’s lab has many more interesting microRNAs to examine, a number of which are conserved between flies and humans. The next experiments will look to further match up different microRNAs with their targets. But Gaul is also very interested in how microRNAs themselves are regulated. "We wanted to know if microRNAs were important and if they were specific, and we got those answers - they affect fundamental pathways and have a limited number of critical targets," Gaul says. "Now we want to connect the microRNAs both to their upstream regulation and to their downstream targets to see where they fit in the developmental gene networks."

Kristine Kelly | EurekAlert!
Further information:
http://www.rockefeller.edu

More articles from Life Sciences:

nachricht Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology

nachricht Scientists generate an atlas of the human genome using stem cells
24.04.2018 | The Hebrew University of Jerusalem

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

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

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

The dispute about the origins of terahertz photoresponse in graphene results in a draw

25.04.2018 | Physics and Astronomy

Graphene origami as a mechanically tunable plasmonic structure for infrared detection

25.04.2018 | Materials Sciences

First form of therapy for childhood dementia CLN2 developed

25.04.2018 | Studies and Analyses

VideoLinks
Science & Research
Overview of more VideoLinks >>>