Identification of Hr38 as a neural activity-induced gene

Silkworms show a reproductive behavior induced by sex pheromone. To elucidate the neral mechanism of sex pheromone induced sexual behavior in the silkworm, we attempted to use the neural activity-induced gene as a neural activity marker. Since no neural activity-induced gene was identified in the silkworm, we conducted screening of neural activity-induced gene using the male silkworm brain. By the screening, we identified Bhr38 as a novel neural activity-induced gene, and succeded to comprehensively map the active neruons in the silkworm brain in response to the sex pheromone exposure. Further, we found that Dhr38, the Drosophila homologue of Bhr38, also expressed in a neural activity dependent manner. These results strongly suggest that Hr38 is a highly conserved neural activity-induced gene. The male silkworms were exposed to the female odor for 30 min (group P). Non-treated male silkworms were used as the control group group C. Ten brains were collected for each sample and stored at -80°C until use. Total RNA was isolated by the TRIzol reagent and subjected to microarray experiments using the custam made (8x16k) Oligo Microarray (Agilent Technologies, Inc.).

家蚕可展现由性信息素（sex pheromone）诱导的生殖行为。为阐明家蚕中性信息素诱导性行为的神经机制，我们尝试将神经活动诱导基因（neural activity-induced gene）作为神经活动标记物。鉴于此前尚未在家蚕中鉴定出该类基因，我们以家蚕雄脑为材料开展了神经活动诱导基因的筛选。通过筛选，我们鉴定出Bhr38为新型神经活动诱导基因，并成功绘制了家蚕雄脑在暴露于性信息素后的活性神经元全图谱。进一步研究发现，Bhr38在果蝇（Drosophila）中的同源基因Dhr38同样以神经活动依赖的方式表达。上述结果强烈表明，Hr38是一类高度保守的神经活动诱导基因。

本实验中，将家蚕雄虫暴露于雌蛾气味中30分钟，设为P组；未作任何处理的家蚕雄虫作为对照组（C组）。每份样本收集10个脑组织，保存于-80℃备用。采用TRIzol试剂提取总RNA，并使用定制化（8×16k）寡核苷酸微阵列（Oligo Microarray，安捷伦科技有限公司，Agilent Technologies, Inc.）开展芯片实验。