Genetic Control of Biogenic-Amine Systems in Drosophila Under Normal and Stress Conditions Akinori Hirashima, 1,3 Madina Jh. Sukhanova, 2 and Inga Yu. Rauschenbach 1 Received 26 Aug. 1999 —Final 15 Mar. 2000 The contents of octopamine and its precursors (tyrosine and tyramine) were studied in adults of two lines of Drosophila virilis with contrasting stress responses. It was demonstrated that in individuals responding to stress by a hormonal stress reaction (line 101), the contents of octopamine and tyrosine are lower than in nonresponding flies (line 147). It was found that there is no difference between the lines in the level of tyramine under normal conditions. The dopamine response to stressor was also studied. Genetic analysis of these differences revealed that they are controlled by a single gene and that the gene is not sex-linked. The gene controlling the response was found to be linked to chromosome 6 of D. virilis. KEY WORDS: octopamine; dopamine; tyrosine; tyramine; Drosophila virilis. INTRODUCTION Biogenic amines are important in insect physiology. It is well known that biogenic amines control energy metabolism in insects and, as releasing factors, regulate the secretion of other hormones (Evans, 1985; Brown and Nestler, 1985). It has been shown that unfavorable conditions cause an increase in the content of biogenic amines, octopamine (OA) and dopamine 1 Division of Bioresource and Bioenvironmental Sciences, Graduate School, Kyushu University, Fukuoka 812-8581, Japan. 2 Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090, Russia. 3 To whom correspondence should be addressed. Fax: +81-92-642-2858/2864. e-mail: ahirasim@agr.kyushu-u.ac.jp. Biochemical Genetics, Vol. 38, Nos. 5/6, 2000 163 0006-2928/00/0600-0163$18.00/0 © 2000 Plenum Publishing Corporation