Harvard
Found your article on "hedgehog molecules" (Harvard Magazine, March-April 1999, p.18) both instructive and highly interesting. I'm a non-biologist, but was pre-med until discovering the fascinations of diplomacy -- so I learned some of the rudiments and have carried on an arms-length interest in things biological. I have an MD nephew and MD son-in law and am a life-long friend of an NIH cancer researcher who has also taught molecular biology at med schools. I tried this idea out on my NIH friend, but he said it was too far out of his field and to try it on someone else. So here goes:
Something triggers gene activity at certain critical points in the development of an embryo. At somel threshold, the blastula folds inwards and forms the vertebral crease -- or whatever. Then at another critical phase, we start getting a cranial bud, then arm and leg buds.
I've pondered and pondered what can trigger activation of these genes in proper sequence. Seems to me -- and this is my proposal to you, someone who's clearly in the mainstream of research in this area -- that one possibility is the build-up of metabolic bi-product, initially in the cells of the blastula, and later in the fetal sac. Could it be that when the concentration of cellular bi-product reaches a certain pH, or the concentration of a given chemical approaches a certain "critical mass", that this triggers the next stage of gene activity. Indeed, that false signals, or false responses, or bio-cellular setback at such critical stages, results in malformation of the fetus by short-circuiting a developmental phase or reinitiating a previous phase. In such cases, the result is usually spontaneous abortion, but depending on circumstances, may result in the birth of a monster.
What do you think? The idea might be worth some laboratory experimentation. It may even yield some surprising insights into gene activity.
Sincerely,
D. B. Timmins (GSAS, PhD '66)
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