Page 143 - Visions of the Future Chemistry and Life Science

132 P. KOHL ET AL.

1990 as an international effort to sequence, by the year 2005, all the 60000
to 80000 human genes in an attempt to make them accessible for bio-
medical handling. By the time this essay is published, about a third of the
human genome will have been accurately sequenced. A decade into the
project, this may seem little, but at the current rate of increase it would
appear that the Genome Project will completed at least two years earlier
than originally planned. The new target date in 2003 would fittingly coin-
cide with the 50th anniversary of Watson and Crick’s description of DNA,
the fundamental structure of our genes.
The Physiome Project should be viewed as both a vision and a route.
It has been portrayed as consisting of two parts (Bassingthwaighte et al.
1998): (i) the databasing of biological information (the ‘Mechanic’s touch’),
and (ii) the development of descriptive and, ultimately, analytical models
of biological function (the ‘Orbiter’s view’). These are by no means sequen-
tial stages of the development.
The Physiome Project will undoubtedly benefit from lessons learned
during the progress of the Genome Project, in particular, that big visions
and small steps (at least initially) are not necessarily a contradiction. It
will, however, have to develop a completely different approach to problem
solving than that used for the Genome Project, as neither the total dimen-
sion of the task (there are ‘only’ 23 human chromosome pairs) nor the size
of the smallest component that needs investigating (DNA bases) can be
defined at the outset of the Physiome Project.
Another difference from the Genome Project is that there will not nec-
essarily be a concerted effort along the whole breadth of the problem.
Biological function may be modelled at any level of functioning – from
protein folding to neuronal networks – and for any tissue, organ or organ
system. Existing examples range from hepatocytes, and pancreatic beta
cells, to muscle fibres, neurones, receptors, etc. Despite this breadth, the
Physiome Project has developed its first significant foundation in the car-
diovascular field.
The reasons for this are diverse and include the fact that models of
cardiac cellular activity were among the first cell models ever developed.
Analytical descriptions of virtually all cardiac cell types are now available.
Also, the large-scale integration of cardiac organ activity is helped
immensely by the high degree of spatial and temporal regularity of
functionally relevant events and structures, as cells in the heart beat
synchronously.