Jump to ContentJump to Main Navigation
SnowbirdIntegrative Biology and Evolutionary Diversity in the Junco$
Users without a subscription are not able to see the full content.

Ellen D. "Ketterson and Jonathan W. Atwell

Print publication date: 2016

Print ISBN-13: 9780226330778

Published to Chicago Scholarship Online: September 2016

DOI: 10.7208/chicago/9780226330808.001.0001

Show Summary Details
Page of

PRINTED FROM CHICAGO SCHOLARSHIP ONLINE (www.chicago.universitypressscholarship.com). (c) Copyright University of Chicago Press, 2020. All Rights Reserved. An individual user may print out a PDF of a single chapter of a monograph in CHSO for personal use.date: 01 June 2020

Diving Deeper into Mechanism

Diving Deeper into Mechanism

Individual and Sex Differences in Testosterone Production, Sensitivity, and Genomic Responses

(p.148) Chapter Seven Diving Deeper into Mechanism

Kimberly A. Rosvall

Christine M. Bergeon Burns

Mark P. Peterson

University of Chicago Press

If we are to understand how hormone-mediated traits evolve, we need to examine the mechanisms underlying individual and sex differences in hormones and their effect on physiology, behavior, and ultimately fitness. This chapter begins to unravel this mechanistic black box, focusing on individual and sex variation in production of testosterone (T), sensitivity to T, and the downstream effects of T on organismal biological processes, employing the dark-eyed junco as a model. Correlational and experimental studies at each of these levels of analysis reveal a remarkable degree of independence among the constituent parts of the endocrine system. Further, although the sexes show striking similarities in the abundance of transcript for sex steroid binding and processing molecules at neural targets, the downstream genomic effects of hormones differ between males and females. Thus, while hormonal pleiotropy produces suites of correlated traits, individual variation in circulating T, sensitivity to T, and T-mediated gene expression exists along many different axes within the endocrine system, providing a multitude of different mechanisms on which selection could act. Likewise, the sexes appear to have found partial solutions to sexual conflict over T at each of these parts of the endocrine system, particularly with respect to the downstream genomic effects of T.

Keywords:   androgen receptor, gene expression, genomic tools, HPG axis, individual variation, integration/independence, LH receptor, sex differences, steroid sensitivity

Chicago Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs, and if you can't find the answer there, please contact us.