Abstract
1. A number of spherical granules containing yellow pigments and isoxanthopterin are found in the hypodermal cells of the lemon and the dilute lemon larvae.
2. The yellow-colored granules have been purified by a new method described in the present study. The chromogranules obtained from the lemon and the dilute lemon larvae show almost the same shape, an irregularly spherical one. The granules obtained from the lemon larvae are much more dense yellow in color than those from the dilute lemon larvae.
3. Similarly shaped granules containing isoxanthopterin but smaller in size than those of the lemon and the dilute lemon larvae are present in the hypodermal cells of normal larvae.
4. The protein composition of the three types of chromogranules obtained from normal, lemon and dilute lemon larvae has been examined by paper electrophoresis, and characteristic differences have been found in their electrophoretic mobility.
5. After the dialysis of the three samples with a visking membrane, the samples have been digested with trypsin and their peptide composition has been examined by high voltage paper electrophoresis and a modified finger printing method. Characteristic differences have been found in the peptide composition of the three types of granules.
6. In the lemon larvae, two supernumeray peptides have been found in addition to the common peptides which occur in the three types of chromoprotein. In the dilute lemon larvae, only one additional peptide has been detected and its Rf value differs from that of the supernumery peptide produced by the 2-P of the lemon sample.
7. The two supernumerary peptides found in the lemon larvae are believed to be components of the specific protein that has the ability to combine with yellow pigments. The single supernumerary peptide found in the dilute lemon larvae is probably an altered specific protein.
8. The specific and the altered specific proteins are apparently produced under the control of the +d-lem and the d-lem gene action, respectively, in the presence of yellow pigments.
