Identification and functional analysis of the genes controlling the relationship between lepidopteran insects and their host plants

鳞翅目昆虫与寄主植物有特殊的关系。桑树含有有毒的拟糖生物碱S，以桑树为食的昆虫必须克服它们的毒性。我们比较了在对生物碱的耐受性中可能起关键作用的米杜特蔗糖酶在桑树取食者(如家蚕和龙须草)和密切相关的非桑树取食者(如变种桑树)之间的功能。结果，我们发现耐生物碱蔗糖酶的mRNAs在桑树饲养者中的表达水平高于非桑树饲养者。我们还发现了一种编码一种酶的基因，这种酶在桑树中的一种成分--栎素的代谢中起着重要作用。

The lepidopteran insects have specific relationships with their host plants. The mulberry contains toxic sugar-mimic alkaloids s, and the insects fed on mulberry must overcome their toxicity. We compared the function of the midut sucrases, which may play a crucial role in the tolerance to the alkaloids, between mulberry feeders such as Bombyx mori and Rondotia menciana and closely-related non-mulberry feeders such as Trilocha varians. As the result, we found that mRNAs for alkaloid-resistant sucrases are more highly expressed in mulberry feeders than in non-mulberry ones. We also found a gene encoding an enzyme that plays an important role in the metabolism of quercetin, a component in mulberry.