Publication Cover
Chronobiology International
The Journal of Biological and Medical Rhythm Research
Volume 31, 2014 - Issue 5
246
Views
6
CrossRef citations to date
0
Altmetric
Research Article

Compression of daily activity time in mice lacking functional Per or Cry genes

, &
Pages 645-654 | Received 15 Nov 2013, Accepted 16 Jan 2014, Published online: 14 Feb 2014
 

Abstract

The adjustment of daily activity time (α) to the varying night length in nocturnal creatures was one of the functions originally attributed to a putative dual oscillator structure of circadian pacemakers in mammals. In two experimental approaches, we tested whether this ability is compromised in mice with functional deletions of one of the four circadian clock genes. First, we tested the capability of α compression by long days in mPer1Brdm1 and mPer2Brdm1 mutant mice. When exposed to a full L:D 18:6 photoperiod, wild-type and mPer1Brdm1 mutant mice show compression followed by decompression of α in DD. mPer2Brdm1 mutant mice did not compress their activity time. The interpretation of these data is, however, complicated by masking due to light. We, therefore, embarked on a second experiment, exploiting skeleton photoperiods. The skeleton photoperiod was changed stepwise from 0 to 24 h, and mCry1 and mCry2 knockout mice were now included in the design. We observed clear and systematic compression of α in wild-type and mCry1 and mCry2 knockout mice. mPer1Brdm1 and mPer2Brdm1 mice both poorly entrained to the skeleton photoperiod. The single mPer2Brdm1 mutant mouse that did entrain did not show α compression. The results show that neither mCry1 nor mCry2 deletions compromise adjustment to day length, consistent with our earlier conclusions on period lengthening in constant light (Spoelstra & Daan, 2008). The mPer2Brdm1 mutant behaves aberrantly and appears not to respond to the delaying action of light in the late subjective day.

Acknowledgments

We thank U. Albrecht and G. T. J. van der Horst for the supply of founder animals for our transgenic mouse colony, Monique Huizinga for animal care, and maintenance and G. J. F. Overkamp for expert technical help.

Log in via your institution

Log in to Taylor & Francis Online

PDF download + Online access

  • 48 hours access to article PDF & online version
  • Article PDF can be downloaded
  • Article PDF can be printed
USD 61.00 Add to cart

Issue Purchase

  • 30 days online access to complete issue
  • Article PDFs can be downloaded
  • Article PDFs can be printed
USD 489.00 Add to cart

* Local tax will be added as applicable

Related Research

People also read lists articles that other readers of this article have read.

Recommended articles lists articles that we recommend and is powered by our AI driven recommendation engine.

Cited by lists all citing articles based on Crossref citations.
Articles with the Crossref icon will open in a new tab.