Acrasin Explained

Each species of slime mold has its own specific chemical messenger, which are collectively referred to as acrasins. These chemicals signal that many individual cells aggregate to form a single large cell or plasmodium.^[1] One of the earliest acrasins to be identified was cyclic AMP, found in the species Dictyostelium discoideum by Brian Shaffer, which exhibits a complex swirling-pulsating spiral pattern when forming a pseudoplasmodium.

The term acrasin was descriptively named after Acrasia from Edmund Spenser's Faerie Queene, who seduced men against their will and then transformed them into beasts. Acrasia is itself a play on the Greek akrasia that describes loss of free will.

Extraction

Brian Shaffer was the first to purify acrasin, now known to be cyclic AMP, in 1954, using methanol.^[2] Glorin, the acrasin of P. violaceum, can be purified by inhibiting the acrasin-degrading enzyme acrasinase with alcohol, extracting with alcohol and separating with column chromatography.^{[3] [4]}

Notes

1. Evidence for the formation of cell aggregates by chemotaxis in the development of the slime mold Dictyostelium discoideum - J.T.Bonner and L.J.Savage Journal of Experimental Biology Vol. 106, pp. 1, October (1947) Cell Biology
2. Aggregation in cellular slime moulds: in vitro isolation of acrasin - B.M.Shaffer Nature Vol. 79, pp. 975, (1953) Cell Biology
3. Identification of a pterin as the acrasin of the cellular slime mold Dictyostelium lacteum - Proceedings of the National Academy of Sciences United States Vol. 79, pp. 6270–6274, October (1982) Cell Biology
4. Hunting Slime Moulds - Adele Conover, Smithsonian Magazine Online (2001)

Notes and References

1. Book: King, Robert C.. A dictionary of genetics. 2013. Oxford University Press. Mulligan, Pamela Khipple, 1953-, Stansfield, William D., 1930-. 978-0-19-937686-5. 8th. New York. 871046520.
2. Shaffer. B. M. . 1956-06-29 . Properties of acrasin . Science . 123. 3209. 1172–1173 . 10.1126/science.123.3209.1172. 0036-8075. 13337336. 1956Sci...123.1172S.
3. Heftmann. Erich. Wright. Barbara E.. Liddel . Gerald U. . Identification of a Sterol with Acrasin Activity in a Slime Mold. December 1959 . Journal of the American Chemical Society . 81. 24 . 6525–6526 . 10.1021/ja01533a054. 0002-7863.
4. Shimomura . O. . Suthers . H. L. . Bonner . J. T.. 1982-12-01 . Chemical identity of the acrasin of the cellular slime mold Polysphondylium violaceum . Proceedings of the National Academy of Sciences . 79. 23. 7376–7379 . 10.1073/pnas.79.23.7376 . 0027-8424 . 6961416 . 347342 . 1982PNAS...79.7376S . free.