Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Why do rodents’ teeth stay sharp? What is the difference between the mouse and the kangaroo?

11.11.2004


Answers to these two questions are given by two recent studies on tooth development and evolution. Scientists at the University of Helsinki have identified the gene responsible for tooth enamel formation, which also explains the sharp incisors of rodents. The second study adds to our knowledge on evolution: the differences between teeth in various species, which have been utilised in evolution research, can be altered through one signalling molecule that regulates development. The research findings will be published this week in two leading scientific journals, Developmental Cell and Nature.



“Enamel gene” explains why rodents’ teeth stay sharp

Scientists at the University of Helsinki Institute of Biotechnology have, in collaboration with their American and Swiss colleagues, identified a novel function for a gene which codes a crucially important signalling molecule, BMP (bone morphogenetic protein). BMP initiates the development of enamel and is, thereby, vital for the formation of enamel.


The scientists have also shown that BMP, together with its specific inhibitor follistatin, explain the special characteristic of rodents’ incisors, their sharp, cutting edge, which stays sharp although the rest of the incisors are worn by gnawing. The sharp edge is caused by the inhibition of BMP signalling molecule in the inner surface of the tooth so that enamel is built only on the outer surface. Thanks to the enamel, the outer surface is harder and will not wear as fast as the inner surface, and a sharp edge is formed at the point where the two surfaces meet.

The fine-tuning of various signalling molecules is the most important mechanism regulating the shape of tissues and organs. The mouse incisor is an illustrative example of how local differences in the activities of the signalling molecules determine the generation of complex structures.

The scientists participating in the study at the University of Helsinki were Xiu-Ping Wang and Marika Suomalainen from the Research Program in Developmental Biology – one of the national Centres of Excellence in Research – and Professor Irma Thesleff, the director of the unit. The results were published in Developmental Cell on 9 November.

One gene brings back teeth of mouse ancestors from 45 million years ago

Tooth fossils are the only remains of many extinct mammals. There are several details in the teeth of different species by which scientists determine the kinship between species. The University of Helsinki evolutionary biologists have shown that several of these characteristics used in evolution research can be changed with one signalling molecule regulating individual development.

The scientists discovered that when the production of a signalling molecule ectodysplasin is increased during development, the mouse teeth develop structures that can be found, for example, in the teeth of the kangaroo. Increasing the secretion of ectodysplasin also causes the mouse to have an extra tooth in a place where the ancestral form of rodents 45 million years ago still had a tooth. If the secretion of ectodysplasin is decreased, however, the mouse’s teeth lose several structures.

The results are beneficial to evolutionary biologists in determining the kinship relations between species, and for developmental biologists when studying why closely related species, such as the chimpanzee and human, have so many structural differences.

The study was conducted by Aapo Kangas, Alistair Evans, Irma Thesleff and Jukka Jernvall from the University of Helsinki Institute of Biotechnology. The study belongs to the field of evolution and developmental biology and its results will be published in Nature on 11 November.

Satu Himanen | alfa
Further information:
http://www.helsinki.fi/university/

More articles from Life Sciences:

nachricht Staying in Shape
16.08.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Chips, light and coding moves the front line in beating bacteria
16.08.2018 | Okinawa Institute of Science and Technology (OIST) Graduate University

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

Staying in Shape

16.08.2018 | Life Sciences

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

16.08.2018 | Earth Sciences

Protein droplets keep neurons at the ready and immune system in balance

16.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>