Aquatic toxicology (Amsterdam, Netherlands)Dec 3, 2014

The toxic algae Alexandrium minutum disrupts daily gene activity, body functions, and behavior in the oyster Crassostrea gigas

Circadian Biology Weekly Brief ↗PubMed ↗DOI ↗

Updated Mar 28, 2026

Abstract

Exposure to the harmful alga Alexandrium minutum disrupts daily rhythms in oysters, impacting gene activity and physiological functions.

Daily activity in the oyster Crassostrea gigas is synchronized by light:dark cycles at the gene level.
A daily rhythm of valve activity and variations in crystalline style length were observed under normal conditions.
Exposure to A. minutum resulted in constant low levels of gene transcription across the daily cycle.
In affected oysters, valve opening duration remained consistently high and variations in crystalline style length diminished.
The disruption of rhythmic activities indicates potential negative impacts on the molecular, physiological, and behavioral functions of oysters.

Simplified

The objective of the present work was to study the effect of the harmful alga Alexandrium minutum on the daily rhythm of the oyster Crassostrea gigas. Many metabolic and physiological functions are rhythmic in living animals. Their cycles are modeled in accordance with environmental cycles such as the day/night cycle, which are fundamental to increase the fitness of an organism in its environment. A disruption of rhythmic activities is known to possibly impact the health of an animal. This study focused in C. gigas, on a gene known to be involved in circadian rhythmicity, cryptochrome gene (CgCry), on putative clock-controlled genes involved in metabolic and physiological functions, on the length cycle of the style, a structure involved in digestion, and on the rhythmicity of valve activity involved in behavior. The results indicate that daily activity is synchronized at the gene level by light:dark cycles in C. gigas. A daily rhythm of valve activity and a difference in crystalline style length between scotophase and photophase were also demonstrated. Additionally, A. minutum exposure was shown to alter cyclic activities: in exposed oysters, gene transcription remained at a constant low level throughout a daily cycle, valve opening duration remained maximal and crystalline style length variation disappeared. The results show that a realistic bloom of A. minutum clearly can disrupt numerous and diverse molecular, physiological and behavioral functions via a loss of rhythmicity.

Full Text

Full text is available at the source.

View Full Text ↗

The toxic algae Alexandrium minutum disrupts daily gene activity, body functions, and behavior in the oyster Crassostrea gigas

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

What Lands in Your Inbox Each Week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

What Lands in Your Inbox Each Week:

Recent issues from the circadian biology brief