Molecular Characterization of Copepod Photoreception

Area of Science:

• Marine Biology
• Molecular Biology
• Genomics

Background:

• Copepods exhibit visually guided behaviors essential for survival.
• Their visual systems, including naupliar eyes and Gicklhorn's organs, vary significantly across species.
• The molecular basis of copepod vision remains largely unexplored.

Purpose of the Study:

• To provide a molecular overview of copepod vision.
• To identify phototransduction genes in diverse copepod species.
• To analyze the evolutionary patterns of opsin gene expression.

Main Methods:

• RNA sequencing and assembly data from 12 copepod species.
• Identification and analysis of phototransduction genes, particularly opsins.
• Ontogenetic expression analysis in *Calanus finmarchicus*.

Main Results:

• Identified 10 expressed transcripts as target genes for copepod phototransduction research.
• All investigated copepods express middle-wavelength-sensitive (MWS) opsins and pteropsins.
• Peropsins and rhodopsin 7 (Rh7) opsins were detected at low levels or specific developmental stages in some species.
• Opsin expression in *Calanus finmarchicus* peaked during early naupliar to copepodite stages.

Conclusions:

• This research lays the foundation for molecular studies of copepod visual systems.
• Opsin gene diversity and differential expression suggest complex visual adaptations in copepods.
• Understanding copepod vision is critical given their ecological importance.