黑腹果蝇对丙酸的产卵避性反应及其生物学意义

Oviposition avoidance of Drosophila melanogaster to propionic acid and its biological significance

【目的】探究丙酸和丁酸对黑腹果蝇Drosophila melanogaster产卵偏嗜性的影响,进一步研究其生物学意义。【方法】利用双选择食物装置检测黑腹果蝇雌性成虫产卵的偏嗜性,利用失去酸感受受体和外科摘除触角的果蝇研究介导该行为的感觉系统,通过发育历期与存活率评价果蝇产卵对丙酸产生避性反应的生物学意义。【结果】黑腹果蝇雌性成虫产卵对丙酸或丁酸产生避性反应,随浓度增大渐趋明显。IR64a与IR76b突变体对0.5%丙酸避性反应减弱,产卵指数分别为-0.07和-0.17。果蝇避开人粪便产卵,产卵指数达-0.7^-0.9,可能为其权衡对乙酸的偏嗜性和对丙酸避性反应的结果。IR64a与IR76b突变体对人粪便避性反应明显减弱,产卵指数分别为-0.49和-0.38。丙酸可显著延缓果蝇后代的发育历期和降低存活率,浓度越大效果越明显,2%浓度时导致果蝇死亡。【结论】果蝇嗅觉系统介导了雌性成虫产卵对丙酸的避性反应,这种行为使果蝇产卵避开丙酸,使后代免受丙酸毒害,从而促进果蝇幼虫的发育和提高后代存活率。

[ Aim ] To explore the effects of propionic and butyric acids on the oviposition preference of Drosophila melanogaster, and to provide an insight into its biological significance. [ Methods ] The 2- choice apparatus was employed to assess the oviposition selection of D. melanogaster female adults. The flies with the acid-sensing gustatory receptors eliminated or the olfactory antennae surgically removed were used to investigate the oviposition-associated sensory system. The developmental duration and survival rate of the fruit fly were utilized to evaluate the biological significance of oviposition avoidance of D. melanogaster to propionic acid. [ Results ] D. melanogaster female adults displayed an oviposition avoidance to propionic and butyric acids in a dosage-dependent manner. The oviposition avoidance of IR64a and IR76b mutants to 0.5% propionic acid was completely impaired with the oviposition index of -0.07 and -0.17, respectively. The female adults repelled human feces to oviposit with the ovipositionindex of -O. 7 - -O. 9, which may be explained by a balanced decision to the attractiveness to acetic acid and the avoidance to propionic acid. IR64a and IR76b mutants showed less oviposition avoidance to human feces with the oviposition index of -O. 49 and -O. 38, respectively. Propionic acid dramatically delayed the developmental duration of their progeny and reduced the survival rate in a dosage-dependent manner, and 2% propionic acid caused death of larvae. [ Conclusion] D. melanogaster female adults repel to lay eggs on food with propionic acid through the olfactory system, and this behavior promotes the development of D. melanogaster larvae and boosts the survival rate of their offspring.