Aurori Cristian M, Giurgiu Alexandru-Ioan, Conlon Benjamin H, Kastally Chedly, Dezmirean Daniel S, Routtu Jarkko, Aurori Adriana
Faculty of Animal Science and Biotechnology University of Agriculture Sciences and Veterinary Medicine Cluj-Napoca Romania.
Molecular Ecology Institute of Biology/Zoology Martin-Luther-University Halle-Wittenberg Halle Germany.
Ecol Evol. 2020 Dec 21;11(2):1057-1068. doi: 10.1002/ece3.7125. eCollection 2021 Jan.
The parasitic mite devastates honey bee () colonies around the world. Entering a brood cell shortly before capping, the mother feeds on the honey bee larvae. The hormones 20-hydroxyecdysone (20E) and juvenile hormone (JH), acquired from the host, have been considered to play a key role in initiating reproductive cycle. This study focuses on differential expression of the genes involved in the biosynthesis of JH and ecdysone at six time points during the first 30 hr after cell capping in both drone and worker larvae of . This time frame, covering the conclusion of the honey bee brood cell invasion and the start of ovogenesis, is critical to the successful initiation of a reproductive cycle. Our findings support a later activation of the ecdysteroid cascade in honey bee drones compared to worker larvae, which could account for the increased egg production of in drone cells. The JH pathway was generally downregulated confirming its activity is antagonistic to the ecdysteroid pathway during the larva development. Nevertheless, the genes involved in JH synthesis revealed an increased expression in drones. The upregulation of gene involved in methyl farnesoate (MF) synthesis came into attention since the MF is not only a precursor of JH but it is also an insect pheromone in its own right as well as JH-like hormone in Acari. This could indicate a possible kairomone effect of MF for attracting the mites into the drone brood cells, along with its potential involvement in ovogenesis after the cell capping, stimulating initiation of egg laying.
寄生螨对全球的蜜蜂（Apis mellifera）蜂群造成了严重破坏。在封盖前不久进入育虫室后，螨妈妈以蜜蜂幼虫为食。从宿主获取的激素20-羟基蜕皮酮（20E）和保幼激素（JH）被认为在启动生殖周期中起关键作用。本研究聚焦于意大利蜜蜂雄蜂和工蜂幼虫在育虫室封盖后的前30小时内六个时间点上，参与JH和蜕皮激素生物合成的基因的差异表达。这个时间段涵盖了蜜蜂育虫室入侵的结束和卵子发生的开始，对成功启动生殖周期至关重要。我们的研究结果表明，与工蜂幼虫相比，意大利蜜蜂雄蜂中蜕皮甾体级联反应的激活时间较晚，这可能解释了螨在雄蜂育虫室中产卵量增加的原因。JH途径总体上被下调，这证实了其在幼虫发育过程中的活性与蜕皮甾体途径相互拮抗。然而，参与JH合成的基因在雄蜂中表达增加。参与法尼醇甲酯（MF）合成的基因上调引起了关注，因为MF不仅是JH的前体，它本身也是一种昆虫信息素，在蜱螨亚纲中还是一种类JH激素。这可能表明MF具有一种可能的利它素效应，能吸引螨进入雄蜂育虫室，同时在育虫室封盖后其可能参与卵子发生，刺激螨开始产卵。
