Title: | Peripheral coding of sex pheromone blends with reverse ratios in two helicoverpa species |
Author(s): | Wu H; Hou C; Huang LQ; Yan FS; Wang CZ; |
Address: | "State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China" |
DOI: | 10.1371/journal.pone.0070078 |
ISSN/ISBN: | 1932-6203 (Electronic) 1932-6203 (Linking) |
Abstract: | "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, 97ratio3 and 7ratio93 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 (100ratio0, 97ratio3, 50ratio50, 7ratio93, 0ratio100). 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 100ratio28.9 and 21.9ratio100 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 microg, 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" |
Keywords: | "Animals Behavior, Animal/drug effects Female Ketones/chemistry/*pharmacology Male Moths Olfactory Receptor Neurons/drug effects Pest Control, Biological/methods Sensory Receptor Cells/*drug effects Sex Attractants/chemistry/*pharmacology;" |
Notes: | "MedlineWu, Han Hou, Chao Huang, Ling-Qiao Yan, Fu-Shun Wang, Chen-Zhu eng Research Support, Non-U.S. Gov't 2013/07/31 PLoS One. 2013 Jul 23; 8(7):e70078. doi: 10.1371/journal.pone.0070078. Print 2013" |