Interdepartmental Neuroscience Program, University of California, Riverside, Riverside, CA 92521, USA.
Department of Biology, Texas A&M University, College Station, TX 77843, USA.
Cell Rep. 2023 Oct 31;42(10):113297. doi: 10.1016/j.celrep.2023.113297.
Comparative studies of related but ecologically distinct species can reveal how the nervous system evolves to drive behaviors that are particularly suited to certain environments. Drosophila melanogaster is a generalist that feeds and oviposits on most overripe fruits. A sibling species, D. sechellia, is an obligate specialist of Morinda citrifolia (noni) fruit, which is rich in fatty acids (FAs). To understand evolution of noni taste preference, we characterized behavioral and cellular responses to noni-associated FAs in three related drosophilids. We find that mixtures of sugar and noni FAs evoke strong aversion in the generalist species but not in D. sechellia. Surveys of taste sensory responses reveal noni FA- and species-specific differences in at least two mechanisms-bitter neuron activation and sweet neuron inhibition-that correlate with shifts in noni preference. Chemoreceptor mutant analysis in D. melanogaster predicts that multiple genetic changes account for evolution of gustatory preference in D. sechellia.
比较相关但生态上不同的物种可以揭示神经系统如何进化以驱动适应特定环境的行为。黑腹果蝇是一种杂食性昆虫，以大多数过熟的水果为食并产卵。它的一个近缘种，D. sechellia，是 Morinda citrifolia（诺丽）果实的专性专食者，这种果实富含脂肪酸（FAs）。为了了解对诺丽果味道偏好的进化，我们研究了三种相关果蝇对与诺丽果相关的 FA 的行为和细胞反应。我们发现，糖和诺丽果 FA 的混合物在这种广食性物种中会引起强烈的厌恶感，但在 D. sechellia 中不会。味觉感觉反应的调查显示，在至少两种机制中，即苦味神经元激活和甜味神经元抑制，存在诺丽果 FA 和物种特异性差异，这与诺丽果偏好的转变相关。在 D. melanogaster 中的化学感受器突变体分析预测，多个遗传变化解释了 D. sechellia 中味觉偏好的进化。
