Channels of Evolution: Unveiling Evolutionary Patterns in Diatom Ca²⁺ Signalling

Area of Science:

• Marine biology
• Cellular signaling
• Genomics

Background:

• Diatoms are crucial primary producers in aquatic ecosystems.
• Understanding diatom environmental sensing mechanisms is limited.
• Calcium (Ca2+) signaling is vital for eukaryotic stimulus perception.

Purpose of the Study:

• To investigate the diversity of Ca2+ channel families in diatom genomes.
• To compare Ca2+ channel distribution across diatom species and with other stramenopiles.
• To elucidate the unique Ca2+ signaling toolkit of diatoms.

Main Methods:

• Bioinformatic analysis of diatom genomes.
• Comparative genomics across stramenopile lineages.
• Identification and characterization of Ca2+ channel families.

Main Results:

• Voltage-gated Ca2+ channels (Ca_v) are present in centric but absent in pennate diatoms.
• Single-domain EukCatA channels are found in all diatoms.
• Glutamate receptors (GLRs), pentameric ligand-gated ion channels (pLGICs), and mitochondrial uniporter (MCU) show varied presence/absence.
• Transient receptor potential (TRP) channels are conserved but lack expansion seen in brown algae.

Conclusions:

• Diatoms possess a unique set of Ca2+ channels for environmental sensing.
• Evolutionary loss or gain of specific Ca2+ channels contributes to interspecies differences in signaling.
• This study provides insights into the molecular basis of diatom environmental responses.