ISSN 00124966, Doklady Biological Sciences, 2013, Vol. 452, pp. 284–286. © Pleiades Publishing, Ltd., 2013. Original Russian Text © I.Yu. Rauschenbach, N.V. Adonyeva, N.V. Faddeeva, L.V. Shumnaya, N.E. Gruntenko, 2013, published in Doklady Akademii Nauk, 2013, Vol. 452, No. 1, pp. 115–117. 284 It is known that under unfavorable conditions all metazoans, including Drosophila, develop a hor monal stress response, which stimulates their adapta tion [1]. It has been demonstrated the stress hormones of Drosophila adults are biogenic amines (octopamine and dopamine), the levels of which sharply increase under stress, as well as gonadotropins (20hydroxy ecdysone (20E) and juvenile hormone (JH)), the titers of which also become higher in the case of stress [2]. Earlier, we found that female Drosophila have a mech anism for reciprocal regulation of their stress hor mones JH and 20E. Maintaining the balance between these hormones is very important for increasing the resistance of Drosophila to different stressors [3]. We have also discovered that Drosophila is characterized by sexual dimorphism with respect to the resistance to the effect of stressors: the survival rate of females affected by thermal stress (38°C) or starvation is sig nificantly higher than that of males [4–6]. It is a common knowledge that the highly con served signaling pathway of insulin/insulinlike growth factor (I/IGF), which is found in all insects (including Drosophila), is involved in the regulation of different functions, such as growth, development, metabolic homeostasis, lifespan, and resistance to stress [7]. There are data that IGF interacts with the stress hormones of Drosophila: (1) expression of the insulin receptor (InR) was found in the corpus allatum (CA), which is a gland synthesizing JH [8]; (2) it was demonstrated in vitro that the InR mutation in Droso phila adults decreased the synthesis of 20E [9] and JH [10]. It has been shown recently that IGF regulates sexual dimorphism of Drosophila with respect to loco motor activity [11]. We assumed that IGFs could be one of the elements of stress response and regulate, either directly or indirectly, through stress hormones, sexual dimorphism of Drosophila with respect to the resistance to stress. In this work, we are going to verify this assumption by studying the effect of thermal stress on the survival rate of Drosophila melanogaster females and males: (1) with a decreased expression of the insulinreceptor gene, InR, in all tissues of the fly; (2) with the expres sion of InR decreased only in the gland synthesizing juvenile hormone (JH); (3) with a pharmacologically increased level of insulin. Four lines of D. melanogaster were used in this study: (1) the wildtype Canton S line, (2) the p[UAS RNAiInR]/CyO transgenic line carrying a genetic construction, antisense suppressor of the InR gene [11], (3) the p[daughterlessGAL4] (daGAL4) trans genic line carrying ubiquitously expressing daGAL4 driver, and (4) the Aug21>/Cyo::armGFP transgenic line carrying Aug21Ga14 driver, which is specifically expressed in the corpus allatum (CA), a gland synthe sizing juvenile hormone [12, 13]. Crossing p[UAS RNAiInR]/CyO and daGAL4 gives rise to two progeny types: (1) daGAL4/UASRNAiInR with a ubiquitous decrease in the expression of InR and (2) daGAL4/СyO with the normal level of insulin receptors. Crossing p[UASRNAiInR]/CyO and Aug21>/Cyo::armGFP also results in two progeny types: (1) Aug21>/UAS RNAiInR with the expression of the InR gene, which is decreased in CA and (2) UASRNAiInR/Cyo::arm GFP with the normal level of insulin receptors in CA. The second progeny type in each of the above cross ings was used as a control group. It was easily differen tiated by the presence of curled wings (Curly). Based on the literature data on the enhancement of RNA interference phenotype during the development of specimens at an increased temperature [14], the cross ings were carried out at 29°C; after the emergence, the flies were exposed to 25°C. The cultures were synchro GENERAL BIOLOGY The Role of the Insulin Signaling Pathway in the Control of the Drosophila Sexual Dimorphism with Respect to Thermal Stress Resistance I. Yu. Rauschenbach, N. V. Adonyeva, N. V. Faddeeva, L. V. Shumnaya, and N. E. Gruntenko Presented by Academician V.K. Shumnyi January 24, 2013 Received January 24, 2013 DOI: 10.1134/S0012496613050025 Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, pr. Akad. Lavrent’eva 10, Novosibirsk, 630090 Russia