Alterations in the activities of tyrosinase, N-acetyltransferase, and tyrosine aminotransferase in immune reactive larvae of Drosophila melanogaster.
The activities of three enzymes, tyrosinase (monophenol oxidase, MPO), N-acetyltransferase (NAT), and tyrosine aminotransferase (TAT), were studied during eumelanotic encapsulation in host larvae of Drosophila melanogaster parasitized by the wasp, Leptopilina boulardi. At 24 h postinfection there was a tenfold increase in the MPO, whereas the activities of NAT and TAT were lower than those of nonparasitized controls. The data suggest that certain developmental processes are temporarily interrupted and alterations made in the metabolism of tyrosine to provide the metabolites necessary for a successful immune response. Two strains of D. melanogaster, R and Tyr-1, were parasitized and found to be immune reactive. The Tyr-1 strain is deficient in tyrosinase during the adult stage, but this mutation was found not to affect the immune capacity of the larvae. This is the first study to document concurrent alterations in the activities of various catecholamine-metabolizing enzymes during an immune response in an insect.
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Department of Biology, Loyola University of Chicago, IL 60626.
Nappi
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Carton
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D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000032:analysis*; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000254:growth & development / Q000276:immunology / Q000469:parasitology; D005260:Female; D006790:Host-Parasite Interactions; D007814:Larva; D008543:Melanins / Q000096:biosynthesis; D014442:Monophenol Monooxygenase / Q000032:analysis* / Q000235:genetics; D014176:Protein Biosynthesis; D011506:Proteins; D014443:Tyrosine / Q000378:metabolism; D014444:Tyrosine Transaminase / Q000032:analysis*; D014863:Wasps / Q000254:growth & development
D008543:Melanins; D011506:Proteins; C013247:sclerotin; C041877:eumelanin; D014443:Tyrosine; D014442:Monophenol Monooxygenase; D001191:Arylamine N-Acetyltransferase; D014444:Tyrosine Transaminase