| 释义 |
acrasin Bot.|ˈækrəsɪn|
[f. mod.L. Acras-is, name of a genus of slime moulds (P. van Tieghem 1880, in Bull. de la Soc. Bot. de France XXVII. 318), f. Gr. ἀ- a- prefix 14 + κρᾶσις fusion: see -in1. Cf. quot. 1969 and acrasy.]
A substance secreted by the cells of some slime moulds which acts as an attractant for them and causes their aggregation.
1947J. T. Bonner in Jrnl. Exper. Zool. CVI. 22 We have deduced..that during the aggregation of Dictyostelium there is some type of chemical substance..produced continuously or at frequent intervals by the center, which freely diffuses, and the myxamoebae move..towards the point of its highest concentration... The term acrasin is suggested, and it can be defined..as a type of substance consisting either of one or numerous compounds which is responsible for stimulating and directing aggregation in certain members of the Acrasiales. 1969― in Sci. Amer. June 80/3, I gave the unidentified attractant the name acrasin because the proper name of the cellular slime molds is Acrasiales, and also because in Edmund Spenser's Faerie Queene there is a witch named Acrasia who attracted men and transformed them into beasts. 1970Nature 26 Sept. 1365/2 Slime mould amoebae are attracted to a certain substance which they secrete themselves. (It is called acrasin, and has been identified in one species as cyclic-AMP2.) |