Belay A T, Scheiner R, So A K-C, Douglas S J, Chakaborty-Chatterjee M, Levine J D, Sokolowski M B
Department of Biology, University of Toronto, Mississauga, Ontario L5L 1C6, Canada.
J Comp Neurol. 2007 Oct 10;504(5):570-82. doi: 10.1002/cne.21466.
The ability to identify and respond to food is essential for survival, yet little is known about the neural substrates that regulate natural variation in food-related traits. The foraging (for) gene in Drosophila melanogaster encodes a cGMP-dependent protein kinase (PKG) and has been shown to function in food-related traits. To investigate the tissue distribution of FOR protein, we generated an antibody against a common region of the FOR isoforms. In the adult brain we localized FOR to neuronal clusters and projections including neurons that project to the central complex, a cluster within the dorsoposterior region of the brain hemispheres, a separate cluster medial to optic lobes and lateral to brain hemispheres, a broadly distributed frontal-brain cluster, axon bundles of the antennal nerve and of certain subesophageal-ganglion nerves, and the medulla optic lobe. These newly described tissue distribution patterns of FOR protein provide candidate neural clusters and brain regions for investigation of neural networks that govern foraging-related traits. To determine whether FOR has a behavioral function in neurons we expressed UAS-for in neurons using an elav-gal4 driver and measured the effect on adult sucrose responsiveness (SR), known to be higher in rovers than sitters, the two natural variants of foraging. We found that pan-neuronal expression of for caused an increase in the SR of sitters, demonstrating a neural function for PKG in this food-related behavior.
识别食物并对其做出反应的能力对生存至关重要，但对于调节与食物相关性状自然变异的神经基质，我们却知之甚少。果蝇中的觅食（for）基因编码一种环鸟苷酸依赖性蛋白激酶（PKG），并已被证明在与食物相关的性状中发挥作用。为了研究FOR蛋白的组织分布，我们制备了一种针对FOR同工型共同区域的抗体。在成年果蝇大脑中，我们将FOR定位到神经元簇和投射部位，包括投射到中央复合体的神经元、大脑半球背后部区域内的一个簇、位于视叶内侧和大脑半球外侧的一个单独簇、广泛分布的前脑簇、触角神经和某些咽下神经节神经的轴突束，以及视叶髓质。这些新描述的FOR蛋白组织分布模式为研究控制觅食相关性状的神经网络提供了候选神经簇和脑区。为了确定FOR在神经元中是否具有行为功能，我们使用elav-gal4驱动子在神经元中表达UAS-for，并测量其对成年果蝇蔗糖反应性（SR）的影响，已知在觅食的两种自然变体中，漫游者的SR高于静坐者。我们发现，for的全神经元表达导致静坐者的SR增加，这表明PKG在这种与食物相关的行为中具有神经功能。
