Publication Date:
2012-07-28
Description:
Many male animals wield ornaments or weapons of exaggerated proportions. We propose that increased cellular sensitivity to signaling through the insulin/insulin-like growth factor (IGF) pathway may be responsible for the extreme growth of these structures. We document how rhinoceros beetle horns, a sexually selected weapon, are more sensitive to nutrition and more responsive to perturbation of the insulin/IGF pathway than other body structures. We then illustrate how enhanced sensitivity to insulin/IGF signaling in a growing ornament or weapon would cause heightened condition sensitivity and increased variability in expression among individuals--critical properties of reliable signals of male quality. The possibility that reliable signaling arises as a by-product of the growth mechanism may explain why trait exaggeration has evolved so many different times in the context of sexual selection.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Emlen, Douglas J -- Warren, Ian A -- Johns, Annika -- Dworkin, Ian -- Lavine, Laura Corley -- New York, N.Y. -- Science. 2012 Aug 17;337(6096):860-4. doi: 10.1126/science.1224286. Epub 2012 Jul 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Biological Sciences, The University of Montana, 104 Health Science Building, Missoula, MT 59812, USA. doug.emlen@mso.umt.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22837386" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Beetles/*anatomy & histology/genetics/*growth & development
;
Gene Knockdown Techniques
;
Horns/*anatomy & histology/*growth & development
;
Insulin/physiology
;
Male
;
*Mating Preference, Animal
;
Molecular Sequence Data
;
Receptor, Insulin/genetics/*physiology
;
*Signal Transduction
;
Somatomedins/physiology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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