Juvenile hormone regulates extreme mandible growth in male stag beetles.

The morphological diversity of insects is one of the most striking phenomena in biology. Evolutionary modifications to the relative sizes of body parts, including the evolution of traits with exaggerated proportions, are responsible for a vast range of body forms. Remarkable examples of an insect tr...

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Main Authors: Hiroki Gotoh, Richard Cornette, Shigeyuki Koshikawa, Yasukazu Okada, Laura Corley Lavine, Douglas J Emlen, Toru Miura
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-01-01
Series:PLoS ONE
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21731659/?tool=EBI
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author Hiroki Gotoh
Richard Cornette
Shigeyuki Koshikawa
Yasukazu Okada
Laura Corley Lavine
Douglas J Emlen
Toru Miura
author_facet Hiroki Gotoh
Richard Cornette
Shigeyuki Koshikawa
Yasukazu Okada
Laura Corley Lavine
Douglas J Emlen
Toru Miura
author_sort Hiroki Gotoh
collection DOAJ
description The morphological diversity of insects is one of the most striking phenomena in biology. Evolutionary modifications to the relative sizes of body parts, including the evolution of traits with exaggerated proportions, are responsible for a vast range of body forms. Remarkable examples of an insect trait with exaggerated proportions are the mandibular weapons of stag beetles. Male stag beetles possess extremely enlarged mandibles which they use in combat with rival males over females. As with other sexually selected traits, stag beetle mandibles vary widely in size among males, and this variable growth results from differential larval nutrition. However, the mechanisms responsible for coupling nutrition with growth of stag beetle mandibles (or indeed any insect structure) remain largely unknown. Here, we demonstrate that during the development of male stag beetles (Cyclommatus metallifer), juvenile hormone (JH) titers are correlated with the extreme growth of an exaggerated weapon of sexual selection. We then investigate the putative role of JH in the development of the nutritionally-dependent, phenotypically plastic mandibles, by increasing hemolymph titers of JH with application of the JH analog fenoxycarb during larval and prepupal developmental periods. Increased JH signaling during the early prepupal period increased the proportional size of body parts, and this was especially pronounced in male mandibles, enhancing the exaggerated size of this trait. The direction of this response is consistent with the measured JH titers during this same period. Combined, our results support a role for JH in the nutrition-dependent regulation of extreme mandible growth in this species. In addition, they illuminate mechanisms underlying the evolution of trait proportion, the most salient feature of the evolutionary diversification of the insects.
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spelling doaj.art-6d5c309cac204a68a0e398f1fbab2f3b2022-12-21T21:46:39ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-0166e2113910.1371/journal.pone.0021139Juvenile hormone regulates extreme mandible growth in male stag beetles.Hiroki GotohRichard CornetteShigeyuki KoshikawaYasukazu OkadaLaura Corley LavineDouglas J EmlenToru MiuraThe morphological diversity of insects is one of the most striking phenomena in biology. Evolutionary modifications to the relative sizes of body parts, including the evolution of traits with exaggerated proportions, are responsible for a vast range of body forms. Remarkable examples of an insect trait with exaggerated proportions are the mandibular weapons of stag beetles. Male stag beetles possess extremely enlarged mandibles which they use in combat with rival males over females. As with other sexually selected traits, stag beetle mandibles vary widely in size among males, and this variable growth results from differential larval nutrition. However, the mechanisms responsible for coupling nutrition with growth of stag beetle mandibles (or indeed any insect structure) remain largely unknown. Here, we demonstrate that during the development of male stag beetles (Cyclommatus metallifer), juvenile hormone (JH) titers are correlated with the extreme growth of an exaggerated weapon of sexual selection. We then investigate the putative role of JH in the development of the nutritionally-dependent, phenotypically plastic mandibles, by increasing hemolymph titers of JH with application of the JH analog fenoxycarb during larval and prepupal developmental periods. Increased JH signaling during the early prepupal period increased the proportional size of body parts, and this was especially pronounced in male mandibles, enhancing the exaggerated size of this trait. The direction of this response is consistent with the measured JH titers during this same period. Combined, our results support a role for JH in the nutrition-dependent regulation of extreme mandible growth in this species. In addition, they illuminate mechanisms underlying the evolution of trait proportion, the most salient feature of the evolutionary diversification of the insects.https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21731659/?tool=EBI
spellingShingle Hiroki Gotoh
Richard Cornette
Shigeyuki Koshikawa
Yasukazu Okada
Laura Corley Lavine
Douglas J Emlen
Toru Miura
Juvenile hormone regulates extreme mandible growth in male stag beetles.
PLoS ONE
title Juvenile hormone regulates extreme mandible growth in male stag beetles.
title_full Juvenile hormone regulates extreme mandible growth in male stag beetles.
title_fullStr Juvenile hormone regulates extreme mandible growth in male stag beetles.
title_full_unstemmed Juvenile hormone regulates extreme mandible growth in male stag beetles.
title_short Juvenile hormone regulates extreme mandible growth in male stag beetles.
title_sort juvenile hormone regulates extreme mandible growth in male stag beetles
url https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21731659/?tool=EBI
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