Three isoforms of complement properdin factor P in trout: cloning, expression, gene organization and constrained...

Area of Science:

• Immunology
• Evolutionary Biology
• Genomics

Background:

• Properdin (factor P) is a key regulator of the complement system, stabilizing the alternative pathway.
• Understanding the molecular evolution of properdin is crucial for insights into immune system development.

Purpose of the Study:

• To clone and characterize three gene isoforms of properdin in rainbow trout (Oncorhynchus mykiss).
• To investigate the molecular evolution of properdin factor P (pfc) in vertebrates.

Main Methods:

• Gene cloning and sequencing of rainbow trout properdin isoforms.
• Bioinformatic analysis of predicted polypeptide sequences and domain architecture.
• Phylogenetic analysis of trout properdin genes.

Main Results:

• Identified three distinct properdin factor P (pfc) gene isoforms (pfc1, pfc2, pfc3) in rainbow trout.
• Trout properdins share high sequence identity (78-90%) and possess conserved domain architecture (six thrombospondin repeat type 1 domains) similar to mammalian counterparts.
• Phylogenetic analysis places trout pfc genes within teleost orthologs, with liver identified as the primary site of mRNA transcription.

Conclusions:

• This is the first report of three separate genes encoding properdin factor P in a vertebrate species.
• The findings provide valuable data on the evolutionary diversification of the complement system's positive regulator.
• Rainbow trout properdin gene structure and expression patterns offer a unique model for studying complement regulation evolution.