Glater Elizabeth E, Rockman Matthew V, Bargmann Cornelia I
Department of Biology, Harvey Mudd College, Claremont, California 91711.
G3 (Bethesda). 2014 Feb 19;4(2):265-76. doi: 10.1534/g3.113.008649.
The nematode Caenorhabditis elegans can use olfaction to discriminate among different kinds of bacteria, its major food source. We asked how natural genetic variation contributes to choice behavior, focusing on differences in olfactory preference behavior between two wild-type C. elegans strains. The laboratory strain N2 strongly prefers the odor of Serratia marcescens, a soil bacterium that is pathogenic to C. elegans, to the odor of Escherichia coli, a commonly used laboratory food source. The divergent Hawaiian strain CB4856 has a weaker attraction to Serratia than the N2 strain, and this behavioral difference has a complex genetic basis. At least three quantitative trait loci (QTLs) from the CB4856 Hawaii strain (HW) with large effect sizes lead to reduced Serratia preference when introgressed into an N2 genetic background. These loci interact and have epistatic interactions with at least two antagonistic QTLs from HW that increase Serratia preference. The complex genetic architecture of this C. elegans trait is reminiscent of the architecture of mammalian metabolic and behavioral traits.
线虫秀丽隐杆线虫能够利用嗅觉区分不同种类的细菌，而细菌是其主要食物来源。我们研究了自然遗传变异如何影响选择行为，重点关注两种野生型秀丽隐杆线虫品系之间嗅觉偏好行为的差异。实验室品系N2强烈偏好粘质沙雷氏菌的气味（一种对秀丽隐杆线虫致病的土壤细菌），而不是常用的实验室食物来源大肠杆菌的气味。与之不同的夏威夷品系CB4856对粘质沙雷氏菌的吸引力比N2品系弱，这种行为差异具有复杂的遗传基础。来自夏威夷品系CB4856（HW）的至少三个效应大小较大的数量性状位点（QTL），当导入N2遗传背景时，会导致对粘质沙雷氏菌的偏好降低。这些位点相互作用，并与来自HW的至少两个增加对粘质沙雷氏菌偏好的拮抗QTL存在上位性相互作用。秀丽隐杆线虫这一性状的复杂遗传结构让人联想到哺乳动物代谢和行为性状的结构。
