Cell and Tissue Research

, Volume 340, Issue 3, pp 497–507

Effect of photoperiod on clock gene expression and subcellular distribution of PERIOD in the circadian clock neurons of the blow fly Protophormia terraenovae

  • Fumiaki Muguruma
  • Shin G. Goto
  • Hideharu Numata
  • Sakiko Shiga
Regular Article

DOI: 10.1007/s00441-010-0966-8

Cite this article as:
Muguruma, F., Goto, S.G., Numata, H. et al. Cell Tissue Res (2010) 340: 497. doi:10.1007/s00441-010-0966-8

Abstract

We examined the effect of photoperiod on the expression of circadian clock genes period (per) and timeless (tim), using quantitative real-time polymerase chain reaction (PCR), and the effect of photoperiod on subcellular distribution of PERIOD (PER), using immunocytochemistry, in the blow fly, Protophormia terraenovae. Under both short-day and long-day conditions, the mRNA levels of per and tim in the brain oscillated, and their peaks and troughs occurred around lights-off and lights-on, respectively. The oscillations persisted even under constant darkness. In the large ventral lateral neurons (l-LNvs), small ventral lateral neurons (s-LNvs), dorsal lateral neurons (LNds), and medial dorsal neurons (DNms), the subcellular distribution of PER-immunoreactivity changed with time. The number of cells with PER-immunoreactivity in the nucleus was highest 12 h after lights-off and lowest 12 h after lights-on, regardless of photoperiod, suggesting that PER nuclear translocation entrains to photoperiod. When temporal changes in the nuclear localization of PER were compared, the neurons could be classified into 2 groups: the l-LNvs were similar to the s-LNvs, and the LNds were similar to DNms. In LNds and DNms, decreasing rates of the number of cells with PER immunoreactivity in the nucleus per brain from the maximum were large as compared with those in l-LNvs and s-LNvs under short-day conditions. These results suggest that photoperiodic information is reflected in the expression patterns of circadian clock genes per and tim and in the subcellular distribution of PER. This observation suggests that the 2 different groups of clock neurons respond to photoperiod in slightly different manners.

Keywords

PERIOD TIMELESS Clock neurons Immunocytochemistry Photoperiodism Protophormia terraenovae (Insecta) 

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Fumiaki Muguruma
    • 1
  • Shin G. Goto
    • 1
  • Hideharu Numata
    • 1
    • 2
  • Sakiko Shiga
    • 1
  1. 1.Department of Biology and Geosciences, Graduate School of ScienceOsaka City UniversityOsakaJapan
  2. 2.Department of Zoology, Graduate School of ScienceKyoto UniversityKyotoJapan

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