Each cusp of our teeth is regulated by genes which carefully control
the development. A similar genetic puzzle also regulates the
differentiation of our other organs and of all living organisms. A team
of researchers at the Institute of Biotechnology of the University of
Helsinki has developed a computer model reproducing population-level
variation in complex structures like teeth and organs. The research
takes a step towards the growing of correctly shaped teeth and other
organs. The results were published last week in Nature, the
esteemed science journal.
Academy Professor Jukka Jernvall and his team investigate the
evolutionary development of mammal teeth. After over 15 years of work,
the team has compiled so much data that the main aspects of a formula
for making teeth are beginning to be clear. The model shows that
regulation of tooth development is already well known. Teeth are a kind
of "model species" for Jernvall’s team, which means that the study
results also tell about the development of other organs.
A mathematical model applied to the teeth of ringed seals
According to a mathematical computer model, a rather simple basic
formula seems to be behind the complex gene puzzle resulting in tooth
formations; the jungle of gene networks has a ‘patterning kernel’
regulating the variation of teeth among individuals in the same
population. Also the variation of human teeth from the incisors to the
molar teeth may result from a single factor regulating cell division.
The researchers tested their theoretical model, which is based on
mouse tooth development, by investigating seal teeth. The Ladoga ringed
seal collection of the Finnish Museum of Natural History at the
University of Helsinki provided an ideal population sample for the
research because dentitions are highly variable.
New teeth and organs?
The mathematical model proposed by the research team may give new
kind of understanding on the formation of organisms’ three-dimensional
shapes: How do different levels of ontogeny function together? What
factors guide the emergence of specific external features? The new
research results may promote medical research, such as growing new
Jernvall is known as an international pioneer in cross-disciplinary
evolutionary development biology. A few years ago, the science journal Nature
chose a teeth evolution work conducted by Jernvall and two post-doc
researchers as one of the 15 educational topics in the field of
evolutionary biology. The research published now was conducted with
Jernvall’s third post-doc researcher, Isaac Salazar-Ciudad.
Salazar-Ciudad currently works at the Autonomous University of Barcelona