Publications by authors named "Wendy Tidhar"

3 Publications

  • Page 1 of 1

Genetic variation in male sexual behaviour in a population of white-footed mice in relation to photoperiod.

Anim Behav 2015 Jun;104:203-212

Department of Biology, College of William and Mary, Williamsburg, VA, U.S.A.

In natural populations, genetic variation in seasonal male sexual behaviour could affect behavioural ecology and evolution. In a wild-source population of white-footed mice, , from Virginia, U.S.A., males experiencing short photoperiod show high levels of genetic variation in reproductive organ mass and neuroendocrine traits related to fertility. We tested whether males from two divergent selection lines, one that strongly suppresses fertility under short photoperiod (responder) and one that weakly suppresses fertility under short photoperiod (nonresponder), also differ in photoperiod-dependent sexual behaviour and responses to female olfactory cues. Under short, but not long, photoperiod, there were significant differences between responder and nonresponder males in sexual behaviour and likelihood of inseminating a female. Males that were severely oligospermic or azoospermic under short photoperiod failed to display sexual behaviour in response to an ovariectomized and hormonally primed receptive female. However, on the day following testing, females were positive for spermatozoa only when paired with a male having a sperm count in the normal range for males under long photoperiod. Males from the nonresponder line showed accelerated reproductive development under short photoperiod in response to urine-soiled bedding from females, but males from the responder line did not. The results indicate genetic variation in sexual behaviour that is expressed under short, but not long, photoperiod, and indicate a potential link between heritable neuroendocrine variation and male sexual behaviour. In winter in a natural population, this heritable behavioural variation could affect fitness, seasonal life history trade-offs and population growth.
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http://dx.doi.org/10.1016/j.anbehav.2015.03.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4428349PMC
June 2015

Insulins, leptin and feeding in a population of Peromyscus leucopus (white-footed mouse) with variable fertility.

Horm Behav 2014 Jun 26;66(1):169-79. Epub 2014 Feb 26.

Department of Biology, College of William and Mary, Williamsburg, VA, USA. Electronic address:

This article is part of a Special Issue "Energy Balance". Natural populations display a variety of reproductive responses to environmental cues, but the underlying physiology that causes these responses is largely unknown. This study tested the hypothesis that heritable variation in reproductive traits can be described by heritable variation in concentrations of hormones critical to both energy balance and reproduction. To test this hypothesis, we used mouse lines derived from a wild population and selectively bred for response to short day photoperiod. Reproductive and metabolic traits of Peromyscus leucopus display heritable variation when held in short photoperiods typical of winter. Our two lines of mice have phenotypes spanning the full range of variation observed in nature in winter. We tested male and female mice for heritable variation in fasted serum concentrations of three hormones involved in energetic regulation: leptin, insulin-like growth factor 1 (IGF-1) and insulin, as well as the effects of exogenous leptin and a high energy diet on reproductive maturation. Exogenous leptin decreased food intake, but protected males from the reduction in testis mass caused by equivalent food restriction in pair-fed, saline-infused controls. A high energy diet resulted in calorie adjustment by the mice, and failed to alter reproductive phenotype. Concentrations of the three hormones did not differ significantly between selection lines but had correlations with measures of food intake, fertility, blood glucose, and/or body mass. There was evidence of interactions between reproductive traits and hormones related to energy balance and reproduction, but this study did not find evidence that variation in these hormones caused variation in reproductive phenotype.
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http://dx.doi.org/10.1016/j.yhbeh.2014.02.006DOI Listing
June 2014

Sex- and concentration-dependent effects of predator feces on seasonal regulation of body mass in the bank vole Clethrionomys glareolus.

Horm Behav 2007 Nov 30;52(4):436-44. Epub 2007 Jun 30.

Aberdeen Centre for Energy Regulation and Obesity (ACERO), School of Biological Sciences, University of Aberdeen, Aberdeen AB14 2TZ, Scotland, UK.

Increased perception of predation risk can cause changes in activity, feeding and reproductive behavior in a wide range of taxa. Many small mammals in the temperate zone exhibit fluctuations in body mass in response to changing photoperiod. Bank voles lose body mass in winter which they regain when photoperiod increases in the spring. To determine if predation risk affects seasonal changes in body mass (BM), bank voles were exposed to two concentrations (low: LC and high: HC) of weasel feces. Food intake (FI) and daily energy expenditure (DEE) were measured to establish if differences in body mass were due to adjustment in energy intake or expenditure. Fecal corticosterone (CORT) was measured to assess whether the voles had detected and responded to predator feces as a physiological stressor. Voles of both sexes had higher levels of fecal CORT in the groups exposed to weasel feces compared to controls. Voles responded to the predator feces in a sex- and concentration-dependent manner. Males responded to LC feces by gaining less mass following the change in photoperiod. This was mediated by reduced FI and higher DEE. Female voles also gained less BM in response to HC feces, but increased both FI and DEE. We hypothesize that males may gain a short-term advantage by lowering BM in response to predation risk, which may be regained without affecting reproductive success. The consequences of mass loss in females may be more significant as this may delay the onset of breeding or reduce the size or number of young, thereby negatively affecting breeding success.
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http://dx.doi.org/10.1016/j.yhbeh.2007.06.009DOI Listing
November 2007