Molecular analysis of clock gene expression in the avian brain

Gisela Helfer, Andrew E Fidler, Daniela Vallone, Nicholas S Foulkes, Roland Brandstaetter

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

Birds are equipped with a complex circadian pacemaking system that regulates the rhythmicity of physiology and behavior. As with all organisms, transcriptional and translational feedback loops of clock genes represent the basic molecular mechanism of rhythm generation in birds. To investigate avian clock gene expression, partial cDNA sequences of six mammalian clock gene homologs (Bmal1, Clock, Per2, Per3, Cry1, and Cry2) and a novel avian cryptochrome gene (Cry4) were cloned from the house sparrow, a model system in circadian research. Expression patterns were analyzed by semi-quantitative RT-PCR and RNase protection assays using total RNA extracted from adult male house sparrow brains. With the exception of Cry4, pronounced rhythmic mRNA expression of all the clock genes analyzed was encountered, with mRNA levels varying considerably between the various genes. Although some basic features of the molecular circadian feedback loop appear to be similar between mammals and birds, the precise phase relationships of the clock gene mRNA rhythms relative to each other and to the light zeitgeber differ significantly between the house sparrow and mammals. Our results point to the existence of differences in the organization of avian and mammalian circadian clock mechanisms.
Original languageEnglish
Pages (from-to)113-127
Number of pages15
JournalChronobiology International
Volume23
Issue number1-2
DOIs
Publication statusPublished - 2006

Fingerprint

Sparrows
Gene Expression
Brain
Genes
Birds
Messenger RNA
Mammals
Cryptochromes
Circadian Clocks
Periodicity
Ribonucleases
Complementary DNA
RNA
Light
Polymerase Chain Reaction
Research

Keywords

  • ARNTL transcription factors
  • animals
  • basic helix-loop-helix transcription factors
  • brain
  • CLOCK proteins
  • cryptochromes
  • complementary DNA
  • flavoproteins
  • gene expression regulation
  • male
  • nuclear proteins
  • messenger RNA
  • reverse transcriptase polymerase chain reaction
  • ribonucleases
  • sparrows
  • trans-activators
  • transcription factors

Cite this

Helfer, G., Fidler, A. E., Vallone, D., Foulkes, N. S., & Brandstaetter, R. (2006). Molecular analysis of clock gene expression in the avian brain. Chronobiology International, 23(1-2), 113-127. https://doi.org/10.1080/07420520500521871

Molecular analysis of clock gene expression in the avian brain. / Helfer, Gisela; Fidler, Andrew E; Vallone, Daniela; Foulkes, Nicholas S; Brandstaetter, Roland.

In: Chronobiology International, Vol. 23, No. 1-2, 2006, p. 113-127.

Research output: Contribution to journalArticle

Helfer, G, Fidler, AE, Vallone, D, Foulkes, NS & Brandstaetter, R 2006, 'Molecular analysis of clock gene expression in the avian brain', Chronobiology International, vol. 23, no. 1-2, pp. 113-127. https://doi.org/10.1080/07420520500521871
Helfer G, Fidler AE, Vallone D, Foulkes NS, Brandstaetter R. Molecular analysis of clock gene expression in the avian brain. Chronobiology International. 2006;23(1-2):113-127. https://doi.org/10.1080/07420520500521871
Helfer, Gisela ; Fidler, Andrew E ; Vallone, Daniela ; Foulkes, Nicholas S ; Brandstaetter, Roland. / Molecular analysis of clock gene expression in the avian brain. In: Chronobiology International. 2006 ; Vol. 23, No. 1-2. pp. 113-127.
@article{83595868f7414972ac66145a17d7e27a,
title = "Molecular analysis of clock gene expression in the avian brain",
abstract = "Birds are equipped with a complex circadian pacemaking system that regulates the rhythmicity of physiology and behavior. As with all organisms, transcriptional and translational feedback loops of clock genes represent the basic molecular mechanism of rhythm generation in birds. To investigate avian clock gene expression, partial cDNA sequences of six mammalian clock gene homologs (Bmal1, Clock, Per2, Per3, Cry1, and Cry2) and a novel avian cryptochrome gene (Cry4) were cloned from the house sparrow, a model system in circadian research. Expression patterns were analyzed by semi-quantitative RT-PCR and RNase protection assays using total RNA extracted from adult male house sparrow brains. With the exception of Cry4, pronounced rhythmic mRNA expression of all the clock genes analyzed was encountered, with mRNA levels varying considerably between the various genes. Although some basic features of the molecular circadian feedback loop appear to be similar between mammals and birds, the precise phase relationships of the clock gene mRNA rhythms relative to each other and to the light zeitgeber differ significantly between the house sparrow and mammals. Our results point to the existence of differences in the organization of avian and mammalian circadian clock mechanisms.",
keywords = "ARNTL transcription factors, animals, basic helix-loop-helix transcription factors, brain, CLOCK proteins, cryptochromes, complementary DNA, flavoproteins, gene expression regulation, male, nuclear proteins, messenger RNA, reverse transcriptase polymerase chain reaction, ribonucleases, sparrows, trans-activators, transcription factors",
author = "Gisela Helfer and Fidler, {Andrew E} and Daniela Vallone and Foulkes, {Nicholas S} and Roland Brandstaetter",
year = "2006",
doi = "10.1080/07420520500521871",
language = "English",
volume = "23",
pages = "113--127",
journal = "Chronobiology International",
issn = "0742-0528",
publisher = "Marcel Dekker Inc.",
number = "1-2",

}

TY - JOUR

T1 - Molecular analysis of clock gene expression in the avian brain

AU - Helfer, Gisela

AU - Fidler, Andrew E

AU - Vallone, Daniela

AU - Foulkes, Nicholas S

AU - Brandstaetter, Roland

PY - 2006

Y1 - 2006

N2 - Birds are equipped with a complex circadian pacemaking system that regulates the rhythmicity of physiology and behavior. As with all organisms, transcriptional and translational feedback loops of clock genes represent the basic molecular mechanism of rhythm generation in birds. To investigate avian clock gene expression, partial cDNA sequences of six mammalian clock gene homologs (Bmal1, Clock, Per2, Per3, Cry1, and Cry2) and a novel avian cryptochrome gene (Cry4) were cloned from the house sparrow, a model system in circadian research. Expression patterns were analyzed by semi-quantitative RT-PCR and RNase protection assays using total RNA extracted from adult male house sparrow brains. With the exception of Cry4, pronounced rhythmic mRNA expression of all the clock genes analyzed was encountered, with mRNA levels varying considerably between the various genes. Although some basic features of the molecular circadian feedback loop appear to be similar between mammals and birds, the precise phase relationships of the clock gene mRNA rhythms relative to each other and to the light zeitgeber differ significantly between the house sparrow and mammals. Our results point to the existence of differences in the organization of avian and mammalian circadian clock mechanisms.

AB - Birds are equipped with a complex circadian pacemaking system that regulates the rhythmicity of physiology and behavior. As with all organisms, transcriptional and translational feedback loops of clock genes represent the basic molecular mechanism of rhythm generation in birds. To investigate avian clock gene expression, partial cDNA sequences of six mammalian clock gene homologs (Bmal1, Clock, Per2, Per3, Cry1, and Cry2) and a novel avian cryptochrome gene (Cry4) were cloned from the house sparrow, a model system in circadian research. Expression patterns were analyzed by semi-quantitative RT-PCR and RNase protection assays using total RNA extracted from adult male house sparrow brains. With the exception of Cry4, pronounced rhythmic mRNA expression of all the clock genes analyzed was encountered, with mRNA levels varying considerably between the various genes. Although some basic features of the molecular circadian feedback loop appear to be similar between mammals and birds, the precise phase relationships of the clock gene mRNA rhythms relative to each other and to the light zeitgeber differ significantly between the house sparrow and mammals. Our results point to the existence of differences in the organization of avian and mammalian circadian clock mechanisms.

KW - ARNTL transcription factors

KW - animals

KW - basic helix-loop-helix transcription factors

KW - brain

KW - CLOCK proteins

KW - cryptochromes

KW - complementary DNA

KW - flavoproteins

KW - gene expression regulation

KW - male

KW - nuclear proteins

KW - messenger RNA

KW - reverse transcriptase polymerase chain reaction

KW - ribonucleases

KW - sparrows

KW - trans-activators

KW - transcription factors

U2 - 10.1080/07420520500521871

DO - 10.1080/07420520500521871

M3 - Article

VL - 23

SP - 113

EP - 127

JO - Chronobiology International

JF - Chronobiology International

SN - 0742-0528

IS - 1-2

ER -