[Quantitative studies on the pigmentation of the eye in the flourmoth ephestia kühniella : III. Pigmentation in the α-strain after injection of high amounts of kynurenine and the attempt of an interpretation].

1. In order to interpret the results of experiments involving the injection of the ommochrome-precursor 3-hydroxykynurenine (3-HOK) into pupae of the red eyed strain and measurement of pigment synthesis (MUTH, 1967, 1968), a model is proposed, based on the following assumptions: a) The presence of cytoplasmatic granules containing RNA is a necessary condition for pigment synthesis. b) The granules originate from preformed material, if the amount of 3-HOK rises in the presence of this material or if the amount of this material rises in the presence of the precursor. The amount of the material being transformed into granules depends on the value of the stationary and on the hight of the rise of the changed variable. The dependence on the precursor is such that the originating granules are saturated by the precursor. c) After a fast synthesis the preformed material becomes inactivated, regardless of whether having been transformed into granules or not. Though the amount of 3-HOK decreases, the rate of inactivation provides a lasting saturation of the granules. 2. The model allows the derivation of a function, which describes the dependence of the rate of ommochrome synthesis on the injected amount of the precursor. 3. The composition of the pigment being synthesized depends on the injected dose. The results are consistent with the assumption that the pigment consists of 2 mixtures,A' andB, the ratio of which,B∶:A' rises with the injected dose. 4. The experimentally obtained values of the mixtureA' fit the function, calculated on the basis of the proposed model.