Campus Units

Ecology, Evolution and Organismal Biology

Document Type

Article

Publication Version

Published Version

Publication Date

2020

Journal or Book Title

Physiological and Biochemical Zoology

Volume

93

Issue

1

First Page

62

Last Page

74

DOI

10.1086/706786

Abstract

Developmental environments can have lasting effects on an individual’s phenotype. In many reptiles, for example, egg incubation temperature permanently determines offspring sex (temperature-dependent sex determination, TSD) and also influences a suite of morphological, physiological, and behavioral traits. Thus, the contributions of sex and incubation temperature to phenotypic variation are difficult to identify because these factors are confounded under TSD. We used chemical manipulations to experimentally decouple gonadal sex and incubation temperature in a turtle with TSD (Chrysemys picta) to examine their relative and interactive effects on variation in incubation duration and offspring size. We show that warm incubation temperature accelerates development as expected and that exogenous estradiol treatment to eggs further shortens incubation duration across all incubation temperatures. Moreover, estradiol unexpectedly induced male development, resulting in male offspring hatching sooner than female offspring. Variation in offspring size was also influenced by incubation temperature and gonadal sex, but interactions between these two variables were relatively small or nonsignificant. The fitness consequences of these effects are unknown, but we provide preliminary results from our attempts at examining the long-term and sex-specific effects of incubation temperature. Manipulative experimental approaches, combined with longer-term experiments that track individuals through reproduction, will provide novel insights into the adaptive significance of developmental plasticity in long-lived organisms.

Comments

This article is published as Warner, Daniel, Timothy Mitchell, Brooke Bodensteiner, and Fredric Janzen. "Sex and incubation temperature independently affect embryonic development and offspring size in a turtle with temperature-dependent sex determination." 93 (2020): 62-74. doi: 10.1086/706786. Posted with permission.

Copyright Owner

The University of Chicago

Language

en

File Format

application/pdf

Available for download on Friday, January 01, 2021

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