Higa I, Fuyama Y
Department of Biology, Tokyo Metropolitan University, Japan.
Genetica. 1993;88(2-3):129-36. doi: 10.1007/BF02424469.
To reveal the genetic mechanism of host selection in a monophagous fruit fly Drosophila sechellia, olfactory responses and oviposition preferences of this species were compared with those of closely related polyphagous species, D. simulans and D. melanogaster. Adult flies of D. sechellia were strongly attracted to the ripe fruit of Morinda citrifolia which is known to be the sole breeding site of this species. They were also attracted to the odor of n-caproic acid which is contained in the ripe fruit of M. citrifolia and is presumably responsible for the characteristic odor of the fruit. In contrast, D. simulans and D. melanogaster showed a strong repulsion to n-caproic acid. In parallel with the olfactory responses, D. sechellia females laid eggs preferentially on a medium containing n-caproic acid, to which the other two species showed an aversion. Genetic analyses using the hybrid progeny between D. sechellia and D. simulans suggested that the species differences in these behaviors are controlled by gene(s) located on the second chromosome.
为揭示单食性果蝇——塞舌尔果蝇（Drosophila sechellia）宿主选择的遗传机制，将该物种的嗅觉反应和产卵偏好与亲缘关系相近的多食性物种——拟暗果蝇（D. simulans）和黑腹果蝇（D. melanogaster）进行了比较。塞舌尔果蝇成虫会被巴戟天成熟果实强烈吸引，已知巴戟天是该物种唯一的繁殖场所。它们还会被巴戟天成熟果实中所含的正己酸气味吸引，这种气味可能是果实特征气味的来源。相比之下，拟暗果蝇和黑腹果蝇对正己酸表现出强烈的排斥反应。与嗅觉反应一致，塞舌尔果蝇雌蝇优先在含有正己酸的培养基上产卵，而另外两个物种对此表现出厌恶。利用塞舌尔果蝇和拟暗果蝇的杂交后代进行的遗传分析表明，这些行为的物种差异由位于第二条染色体上的基因控制。
