Format

Send to

Choose Destination
PLoS One. 2011;6(9):e25072. doi: 10.1371/journal.pone.0025072. Epub 2011 Sep 19.

Circadian cycles of gene expression in the coral, Acropora millepora.

Author information

1
Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.

Abstract

BACKGROUND:

Circadian rhythms regulate many physiological, behavioral and reproductive processes. These rhythms are often controlled by light, and daily cycles of solar illumination entrain many clock regulated processes. In scleractinian corals a number of different processes and behaviors are associated with specific periods of solar illumination or non-illumination--for example, skeletal deposition, feeding and both brooding and broadcast spawning.

METHODOLOGY/PRINCIPAL FINDINGS:

We have undertaken an analysis of diurnal expression of the whole transcriptome and more focused studies on a number of candidate circadian genes in the coral Acropora millepora using deep RNA sequencing and quantitative PCR. Many examples of diurnal cycles of RNA abundance were identified, some of which are light responsive and damped quickly under constant darkness, for example, cryptochrome 1 and timeless, but others that continue to cycle in a robust manner when kept in constant darkness, for example, clock, cryptochrome 2, cycle and eyes absent, indicating that their transcription is regulated by an endogenous clock entrained to the light-dark cycle. Many other biological processes that varied between day and night were also identified by a clustering analysis of gene ontology annotations.

CONCLUSIONS/SIGNIFICANCE:

Corals exhibit diurnal patterns of gene expression that may participate in the regulation of circadian biological processes. Rhythmic cycles of gene expression occur under constant darkness in both populations of coral larvae that lack zooxanthellae and in individual adult tissue containing zooxanthellae, indicating that transcription is under the control of a biological clock. In addition to genes potentially involved in regulating circadian processes, many other pathways were found to display diel cycles of transcription.

PMID:
21949855
PMCID:
PMC3176305
DOI:
10.1371/journal.pone.0025072
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center