Cytoclesis: The Call of Cell to Cell

CYTOCLESIS: THE CALL OF CELL TO CELL MICHAEL KELLY* An editorial plea for teleology [i] reminds me of something Frederic WoodJones said at Brisbane in 1931 [2]: "To admire the perfection ofan adaptation is to be suspect ofa beliefin teleology, and at the end ofdie nineteenth century it were better that a man should believe in a geocentric universe than diat he should be branded as a ideologist." But teleology, in its original sense ofrelating to final causes, is not the right word for those who do not look for final causes but do take into account the immediate purpose of an organ or a biological process. McClure [3] has recendy pointed out diat we collect more and more details about die chemical properties of protoplasm, in the hope that vitalinformationisjustarounddiecorner. Thisagainremindedme ofwhat Wood Jones said in Adelaide in 1923 [4]: "So much modern work has progressed upon purely physical or chemical lines ofresearch that we are, maybe, in some danger of regarding die body as a test tube in which chemical reactions occur, or as a thing ofwhich the whole ordered building is a mere matter ofsimple physical laws." The ultimate goal ofall biology is the comprehension ofthe nature of living tissue. Unfortunately, many biologists are pessimistic and cannot raise dieir hopes to diis level. The endless extraction of factual data has proceeded to die point where it cannot be co-ordinated. But, says McClure , we have no sensory mechanism for appreciating the interplay of the forces which maintain the unstable equilibrium of living tissue [3]. Measured electrically, the passage of a nerve-impulse weaves in 1/100 of a second spatio-temporal patterns of unimaginable complexity, each nerve being related to so many converging and diverging patterns. Eccles [5] suggests that biology cannot be simplified without new concepts. The late Charles Oberling [6] said recendy that our generation ofbiolo- * Institute ofRheumatology, 410 Albert Street, East Melbourne, Australia. I28 Michael Kelly · Cytoclesis Perspectives in Biology and Medicine · Autumn 1962 gists had lost Virchow's [7] clear vision ofthe cell as die unit oflife widi absolute rule over its cell-territory; that advances in electron microscopy and cytochemistry had revealed nodiing about the cell that Virchow did not know, either by direct vision or by deduction. Possibly more important than the structure ofthe minute components ofthe cell is die capacity ofcells toaffectoneanother. Herearethepropertiespossessedbyallembryonic cells: (a) mobility orameboid movement; (b) phagocytosis and pinocytosis ; (c) secretory or excretory activity; (d) chemical and mechanical irritabüity; (e) excitability or generation of impulses; (/) receptivity to excitationfrom other cells; (g) conductivity; (h) growth andreproduction. Excitation consists of acceleration of the fundamental activities of the cell. As the cells mature, they lose some ofdie above qualities and concentrate on others; in tissue culture they become again like embryonic cells. Nerve cells concentrate on excitation and conduction, but diey retain some secretory and phagocytic powers. Sherrington described die cell as a "field of ceaseless energy, where internal energy is being liberated, whence chemical, diermal, mechanical and electrical effects appear" [8]. If we had a single word to signify cellular activity in the emission of impulses and in influencing other cells, these matters would be much easier to discuss. James Mackenzie clearly described life as a separate form of energy, not explicable in terms of heat or light or electricity (its byproducts ) [9]. But he did not supply die needed word. Wood Jones in Adelaide created a new word [4]. He consulted DarnleyNaylor, Adelaide Professor of Greek, who suggested "cytoclesis"—the call of cell to cell. "Clesis" in Greek means a call; Wartenberg more recendy suggested "padioclisis" to indicate specific affinities in pathology [10]. Spemann later used the word "evocator," which is Latin for "something which calls" [11]; embryonic cells manufacture evocator substances which call other cells into line. Thetermwasusedin 1958 byWillis [12]. Buttheevanescent dissolved substances (now called organizers) compose only a small fraction ofthe total effort ofthe cell. The specificity ofthe cell insures that the right kind ofevocator substance is produced at die right time and place. Here are a few extracts from WoodJones's paper [4]: The whole wonderful contrivance by which the sensory stimulus ofthe contact with the nipple produces the appropriate motor response ofthe...