Rescue of the learning defect in dunce, a Drosophila learning mutant, by an allele of rutabaga, a second learning mutant

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 87; no. 7; pp. 2795 - 2799
• Main Author: Feany, M.B. (Harvard Medical School, Boston, MA)
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01-04-1990; National Acad Sciences
• Subjects: 3',5'-Cyclic-AMP Phosphodiesterases - genetics; 3',5'-Cyclic-AMP Phosphodiesterases - metabolism; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; ADENYLATE CYCLASE; Adenylyl Cyclases - genetics; Adenylyl Cyclases - metabolism; Alleles; ANIMAL PHYSIOLOGY; Animals; Associative learning; Biochemistry; Biological and medical sciences; Calcium; Classical genetics, quantitative genetics, hybrids; Cyclic AMP - metabolism; Diptera; DROSOPHILA; Drosophila - enzymology; Drosophila - genetics; Drosophilidae; EDUCACION; EDUCATION; Educational activities; ENZYMIC ACTIVITY; FISIOLOGIA ANIMAL; Fundamental and applied biological sciences. Psychology; Genetic loci; Genetic mutation; Genetics of eukaryotes. Biological and molecular evolution; Genotype; Learning; LIASAS; LYASE; LYASES; MUTANT; MUTANTES; MUTANTS; Mutation; NERVOUS SYSTEM; PHYSIOLOGIE ANIMALE; SISTEMA NERVIOSO; SYSTEME NERVEUX; Turnips; Vertebrata; Calcium; Enzyme; Insecta; Drosophila; Cyclic AMP; Metabolism; Drosophilidae; Learning; Adenylate cyclase; Allele; Arthropoda; Mutation; Invertebrata; Diptera
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.87.7.2795

rutabaga1(rut1), a Drosophila learning mutant, has adenylate cyclase (EC 4.6.1.1) with reduced basal activity and the absence of calcium/calmodulin-stimulated activity. A second learning mutant, dunce, is defective in cyclic AMP degradation due to decreased or absent phosphodiesterase activity. These opposing biochemical defects allow rut1to partially suppress the female sterility caused by elevated cyclic AMP levels in dunce flies. Selection of mutations that suppress dunce sterility has led to the isolation of two rutabaga alleles. The alleles (rut2and rut3) decrease basal adenylate cyclase activity [Bellen, H. J., Gregory, B. K., Olsson, C. L. \& Kiger, J. A. (1987) Dev. Biol. 121, 432-444] but, unlike the original rutabaga mutation, leave the calcium/calmodulin-stimulated activity intact. Behaviorally, the two alleles also differ from rut1. One of the mutations partially rescues the dunce learning defect, and flies bearing both alleles learn. Calcium responsiveness may thus be the crucial component of adenylate cyclase activity required for associative learning.