THE MOLECULAR BASIS FOR THE REGIONAL PATTERNING IN EMBRYOS

A Lecture by Professor Johnathan Slack, Bath University, on 2 March 1998

Professor Slack was at Oxford and Edinburgh Universities before joining the Imperial Cancer Research Fund for 19 years. He then came to the Department of Biological Sciences and has recently been in the newspapers for his work on headless frogs, which are ‘ regionally patterned embryos’.

In this most instructive and controversial lecture Professor Slack began by describing the process of embryological development. In the past, embryologists described the stages of the process and found that there is some trans-species compatibility and, further, that transplantation of embryological material to an abnormal position was possible.
It was discovered by developmental biologists, as they now prefer to be called, that, contrary to expectation, the control of development began posterially and spread anterially in overlapping waves. By inhibiting some of the stages with various complex organic compounds, such as the Hox gene, one could intervene in the different steps of the development.
It is now just possible, for example, to take a patient's cell, grow it in a culture medium, alter it and fertilise it to produce a ‘designed embryo’, which can be implanted in a ‘mother’ (biological or mechanical) to produce the required vital organ compatible with the patient for subsequent transplantation.
A lively discussion was conducted with speakers ranging from those who thought we were all only proteins to those who advocated the teaching of Wisdom at Universities. Those concerned with ethical problems evisaged a Pandora's Box and would very much have preferred the development of a sac containing the required organs, but feared the development of semi-human individuals. However, it was generally felt that this was a misunderstanding of the technical process with its selectivity and specificity and that the production of a leser race of ‘designer animals’ was a matter of choice not chance. Caution and the need for thorough risk assessment were emphasised, although there was a fascination with the prospect of treating disease.

Dr Mario Nigi.
[The Horizon programme on BBC1 on 22 March described the discovery of Hox genes and their effect on call growth. - Ed.]