State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
PLoS One. 2013 Jul 23;8(7):e70078. doi: 10.1371/journal.pone.0070078. Print 2013.
The relative proportions of components in a pheromone blend play a major role in sexual recognition in moths. Two sympatric species, Helicoverpa armigera and Helicoverpa assulta, use (Z)-11-hexadecenal (Z11-16: Ald) and (Z)-9-hexadecenal (Z9-16: Ald) as essential sex pheromone components but in very different ratios, 97∶3 and 7∶93 respectively. Using wind tunnel tests, single sensillum recording and in vivo calcium imaging, we comparatively studied behavioral responses and physiological activities at the level of antennal sensilla and antennal lobe (AL) in males of the two species to blends of the two pheromone components in different ratios (100∶0, 97∶3, 50∶50, 7∶93, 0∶100). Z11-16: Ald and Z9-16: Ald were recognized by two populations of olfactory sensory neurons (OSNs) in different trichoid sensilla on antennae of both species. The ratios of OSNs responding to Z11-16:Ald and Z9-16:Ald OSNs were 100∶28.9 and 21.9∶100 in H. armigera and H. assulta, respectively. The Z11-16:Ald OSNs in H. armigera exhibited higher sensitivity and efficacy than those in H. assulta, while the Z9-16:Ald OSNs in H. armigera had the same sensitivity but lower efficacy than those in H. assulta. At the dosage of 10 µg, Z11-16: Ald and Z9-16: Ald evoked calcium activity in 8.5% and 3.0% of the AL surface in H. armigera, while 5.4% and 8.6% of AL in H. assulta, respectively. The calcium activities in the AL reflected the peripheral input signals of the binary pheromone mixtures and correlated with the behavioral output. These results demonstrate that the binary pheromone blends were precisely coded by the firing frequency of individual OSNs tuned to Z11-16: Ald or Z9-16: Ald, as well as their population sizes. Such information was then accurately reported to ALs of H. armigera and H. assulta, eventually producing different behaviors.
信息素混合物中成分的相对比例在鳞翅目昆虫的性识别中起着重要作用。两种同域物种，棉铃虫和烟实夜蛾，使用（Z）-11-十六碳烯醛（Z11-16：Ald）和（Z）-9-十六碳烯醛（Z9-16：Ald）作为重要的性信息素成分，但比例非常不同，分别为 97∶3 和 7∶93。通过风洞试验、单感器记录和体内钙成像，我们比较研究了两种物种雄蛾对两种信息素成分不同比例混合物（100∶0、97∶3、50∶50、7∶93、0∶100）的行为反应和触角感觉神经元（OSNs）和触角叶（AL）水平的生理活性。Z11-16：Ald 和 Z9-16：Ald 被两种物种触角上不同的毛形感器中的两个种群的嗅觉感觉神经元（OSNs）识别。对 Z11-16：Ald 和 Z9-16：Ald OSNs 有反应的 OSNs 比例分别为 100∶28.9 和 21.9∶100，在棉铃虫和烟实夜蛾中。棉铃虫中的 Z11-16：Ald OSNs 比烟实夜蛾中的 OSNs 具有更高的敏感性和功效，而棉铃虫中的 Z9-16：Ald OSNs 具有相同的敏感性但功效较低。在 10µg 剂量下，Z11-16：Ald 和 Z9-16：Ald 在棉铃虫的 AL 表面诱发钙活动的比例分别为 8.5%和 3.0%，而在烟实夜蛾中的比例分别为 5.4%和 8.6%。AL 中的钙活性反映了二元信息素混合物的外周输入信号，并与行为输出相关。这些结果表明，二元信息素混合物通过调谐到 Z11-16：Ald 或 Z9-16：Ald 的单个 OSNs 的发射频率以及它们的种群大小进行精确编码。然后，这种信息被准确地报告给棉铃虫和烟实夜蛾的 ALs，最终产生不同的行为。
