26 Colchicine 



Dustin, Sr., stands correct.-"' Almost universally, living cells respond 

 to colchicine after one basic pattern, and new tests extend knowl- 

 edge into other areas of science. The "colchicine-niitosis"^*'* (abbrevi- 

 ated, c-mitosis) is built upon the principle of an arrested metaphase. 

 A c-mitosis was conceived from experiments with plants after the 

 idea had been developed from animal cells. ^-- ^•''- "'• *"'- Undoubtedly, 

 the interest in colchicine by the biologist has stimulated an extensive 

 research in the chemistry of this substance.-^ 



Metaphasic arrest implies control over dividing cells; seemingly 

 then, control over cancer might be obtained from the use of this 

 chemical or others. This discovery raised hopes and new questions 

 about the problem. However, biological problems being as complex 

 as they are — and cancer is a major one — the answers have not come 

 to us as definitely as might have been hoped or expected. Neverthe- 

 less, basic contributions to knowledge such as the idea of metaphasic 

 arrest opened new frontiers in research,''-' even though magic cures 

 have not been produced. 



Chromosomal numbers in plant cells are frequently doubled after 

 treatment with colchicine; polyploidy is a consequence of contact 

 with the drug.-"" Since many species, including those important eco- 

 nomically, i.e., wheat, cotton, oats, and tobacco, are natural poly- 

 ploids, the suggestion was frequently made that this tool would help 

 create new "synthetic" plants according to man's desires.-^- A revolu- 

 tion in agriculture was predicted when colchicine became known 

 for its capacity to induce polyploidy. But many were disappointed 

 as the heralded magic did not apj^ear with each newly created tetra- 

 ]jloid plant. •■' Informed geneticists, acquainted with polyploidy as a 

 l^hint-breeding method,''- did not underestimate the difficulties, nor 

 did they fail to appreciate the opportunities provided by this new 

 tool. Unfortunately, some practical agronomists"^ have condemned 

 the use of colchicine for its failure to produce practical residts within 

 a short time; therefore, such research using induced polyploidy has 

 been discouraged. Nevertheless, the technique is valuable for those 

 able to direct such plant breeding, harmonizing theoretical and practi- 

 cal knowledge. For by these methods, mankintl's food and fiber supply 

 can be increased (cf. (;ha|jters 12 and 13). 



2.2: The Original Statements 



When nuclear mitoses in the grafted sarcoma of the mouse were 

 treated with colchicine,-"' deviations from normal division gave the 

 observer a j^icture of an arrested mitosis. In 1934, Professor A. P. 

 Dustin made the following description: 



. . . after a very short prophase, the niulear membrane disappears, the cyto- 

 plasm swells, and the chromosomes chunp together in a strongly bas()|)hilic 

 mass. The mitoses remain arrested in tliat state for al)out twentv-foiu' hours. 



