TY - JOUR
T1 - Pheromone Odorant Receptor Responses Reveal the Presence of a Cryptic, Redundant Sex Pheromone Component in the European Corn Borer, Ostrinia nubilalis
AU - Wanner, Kevin W.
AU - Moore, Kevin
AU - Wei, Jianrong
AU - Herdlicka, Brent C.
AU - Linn, Charles E.
AU - Baker, Thomas C.
N1 - Funding Information:
We thank Callie Musto for maintaining the moth colonies. Kevin Moore was an undergraduate at Hobart and William Smith Colleges, Geneva, NY participating in a Summer Scholars Program supported by funding from the David and Brenda Rickey Foundation. Research in Geneva was supported by the USDA AFRI program grant 2009-0987-01. KWW was supported by US Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) Awards 2010-65105-20627 and 2014-67013-21859.
Publisher Copyright:
© 2020, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - Two odorant receptors (ORs), OnubOR3 and OnubOR6, in the sex pheromone communication systems of E- and Z-strain European corn borers, Ostrinia nubilalis, were broadly receptive to analogs of their pheromone components. In addition to responding to their natural 14-carbon pheromone components, (Z)-11- and (E)-11-tetradecenyl acetates (Z11- and E11-14:OAc), these pheromone ORs responded to the longer-chain compounds, (Z)-11- and (E)-11-hexadecenyl acetate (Z11- and E11-16:OAc). Z11-16:OAc is a pheromone gland constituent of E-strain O. nubilalis females in Europe but has not previously been shown to have behavioral activity to males. Here, we demonstrate that Z11-16:OAc evokes high levels of upwind flight and source location in E-strain males when substituted for Z11-14:OAc (minor component) in the E-strain blend. Since Z11-16:OAc is found in the gland and has behavioral activity when Z11-14:OAc is missing, then it should be classified as a cryptic, redundant minor pheromone component in E-strain O. nubilalis. The opposite geometric isomer, E11-16:OAc, also functions in Z-strain O. nubilalis, substituting behaviorally for the E11-14:OAc minor component, but has not been found in Z-strain female glands. Single-sensillum recordings showed that sensory neurons of E- and Z-strain male antennae expressing OnubOR3 and OnubOR6 produced responses to these hexadecenyl acetates similar to those evoked by the natural (tetradecenyl acetate) pheromone components. We postulate that the wide responsiveness of these two ORs to the 16-carbon acetates could be a preadaptation for O. nubilalis to use these compounds as minor components in lieu of the respective 14-carbon acetates. Alternatively, the responsiveness of OnubOR3 to E11-16:OAc and OnubOR6 to Z11-16:OAc could represent a vestigial state of these receptors, with the 16-carbon acetates having previously acted as functional minor components in an ancestral blend.
AB - Two odorant receptors (ORs), OnubOR3 and OnubOR6, in the sex pheromone communication systems of E- and Z-strain European corn borers, Ostrinia nubilalis, were broadly receptive to analogs of their pheromone components. In addition to responding to their natural 14-carbon pheromone components, (Z)-11- and (E)-11-tetradecenyl acetates (Z11- and E11-14:OAc), these pheromone ORs responded to the longer-chain compounds, (Z)-11- and (E)-11-hexadecenyl acetate (Z11- and E11-16:OAc). Z11-16:OAc is a pheromone gland constituent of E-strain O. nubilalis females in Europe but has not previously been shown to have behavioral activity to males. Here, we demonstrate that Z11-16:OAc evokes high levels of upwind flight and source location in E-strain males when substituted for Z11-14:OAc (minor component) in the E-strain blend. Since Z11-16:OAc is found in the gland and has behavioral activity when Z11-14:OAc is missing, then it should be classified as a cryptic, redundant minor pheromone component in E-strain O. nubilalis. The opposite geometric isomer, E11-16:OAc, also functions in Z-strain O. nubilalis, substituting behaviorally for the E11-14:OAc minor component, but has not been found in Z-strain female glands. Single-sensillum recordings showed that sensory neurons of E- and Z-strain male antennae expressing OnubOR3 and OnubOR6 produced responses to these hexadecenyl acetates similar to those evoked by the natural (tetradecenyl acetate) pheromone components. We postulate that the wide responsiveness of these two ORs to the 16-carbon acetates could be a preadaptation for O. nubilalis to use these compounds as minor components in lieu of the respective 14-carbon acetates. Alternatively, the responsiveness of OnubOR3 to E11-16:OAc and OnubOR6 to Z11-16:OAc could represent a vestigial state of these receptors, with the 16-carbon acetates having previously acted as functional minor components in an ancestral blend.
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U2 - 10.1007/s10886-020-01196-0
DO - 10.1007/s10886-020-01196-0
M3 - Article
C2 - 32676764
AN - SCOPUS:85087987630
VL - 46
SP - 567
EP - 580
JO - Journal of Chemical Ecology
JF - Journal of Chemical Ecology
SN - 0098-0331
IS - 7
ER -