The Effect of Different Photoperiods in Circadian Rhythms of Per3 Knockout Mice

Author(s)

Pereira, D. S. ; van der Veen, D. R. ; Goncalves, B. S. B. ; Tufik, S. ; von Schantz, M. ; Archer, S. N. ; Pedrazzoli, M.

• Document type: Journal article
• Source: BIOMED RESEARCH INTERNATIONAL; v. 2014, p. 5-pg., 2014-01-01.

Abstract

The aim of this study was to analyse the circadian behavioural responses of mice carrying a functional knockout of the Per3 gene (Per3(-/-)) to different light : dark (L : D) cycles. Male adult wild- type (WT) and Per3(-/-) mice were kept under 12- hour light : 12hour dark conditions (12L : 12D) and then transferred to either a short or long photoperiod and subsequently released into total darkness. All micewere exposed to both conditions, and behavioural activity datawere acquired through runningwheel activity and analysed for circadian characteristics during these conditions. We observed that, during the transition from 12L : 12D to 16L : 8D, Per3(-/-)mice take approximately one additional day to synchronise to the new L : D cycle compared toWT mice. Under these long photoperiod conditions, Per3(-/-) mice were more active in the light phase. Our results suggest that Per3(-/-) mice are less sensitive to light. The data presented here provides further evidence that Per3 is involved in the suppression of behavioural activity in direct response to light. (AU)

• FAPESP's process: 07/05037-9 - Phenotypic characterization of Knock-in and Knock-out Per3 mice in different photoperiod.
• Grantee: Danyella Silva Pereira
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 98/14303-3 - Center for Sleep Studies
• Grantee: Sergio Tufik
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC