Osborne K A, de Belle J S, Sokolowski M B
Department of Biological Sciences, University of Nevada, Las Vegas 89154, USA.
Chem Senses. 2001 Feb;26(2):223-30. doi: 10.1093/chemse/26.2.223.
Drosophila larvae and adults exhibit a naturally occurring genetically based behavioural polymorphism in locomotor activity while foraging. Larvae of the rover morph exhibit longer foraging trails than sitters and forage between food patches, while sitters have shorter foraging trails and forage within patches. This behaviour is influenced by levels of cGMP-dependent protein kinase (PGK) encoded by the foraging (for) gene. Rover larvae have higher expression levels and higher PGK activities than do sitters. Here we discuss the importance of the for gene for studies of the mechanistic and evolutionary significance of individual differences in behaviour. We also show how structure-function analysis can be used to investigate a role for mushroom bodies in larval behaviour both in the presence and in the absence of food. Hydroxyurea fed to newly hatched larvae prevents the development of all post-embryonically derived mushroom body (MB) neuropil. This method was used to ablate MBs in rover and sitter genetic variants of foraging to test whether these structures mediate expression of the foraging behavioural polymorphism. We found that locomotor activity levels during foraging of both the rover and sitter larval morphs were not significantly influenced by MB ablation. Alternative hypotheses that may explain how variation in foraging behaviour is generated are discussed.
果蝇幼虫和成虫在觅食时表现出一种基于遗传的自然行为多态性，即运动活动方面的差异。漫游型幼虫的觅食路径比留守型幼虫长，会在食物斑块之间觅食，而留守型幼虫的觅食路径较短，在斑块内觅食。这种行为受觅食（for）基因编码的环磷酸鸟苷依赖性蛋白激酶（PGK）水平的影响。漫游型幼虫的表达水平和PGK活性比留守型幼虫高。在此，我们讨论for基因对于研究行为个体差异的机制和进化意义的重要性。我们还展示了如何利用结构 - 功能分析来研究在有食物和无食物情况下蘑菇体在幼虫行为中的作用。给刚孵化的幼虫喂食羟基脲可阻止所有胚胎后衍生的蘑菇体（MB）神经纤维网的发育。该方法用于在觅食基因的漫游型和留守型遗传变体中消融蘑菇体，以测试这些结构是否介导觅食行为多态性的表达。我们发现，漫游型和留守型幼虫形态在觅食期间的运动活动水平均未受到蘑菇体消融的显著影响。我们还讨论了可能解释觅食行为差异是如何产生的其他假设。
