Iron metabolic pathways in the processes of sponge plasticity

Area of Science:

• Marine Biology
• Evolutionary Biology
• Biochemistry

Background:

• Oxygen consumption regulation is linked to iron metabolism, extensively studied in mammals but less so in invertebrates.
• Sea sponges, the oldest animal phylum, possess remarkable structural plasticity and regenerative capabilities.

Purpose of the Study:

• Investigate iron metabolic factors and their expression during the reaggregation process in sea sponges.
• Analyze evolutionary trends of iron metabolism genes in sponges.
• Elucidate the role of iron regulation in sponge structural plasticity and morphogenetic processes.

Main Methods:

• De novo transcriptome assembly using RNA-Seq data from Halichondria panicea and Halisarca dujardini.
• Bioinformatic analysis to study evolutionary trends of iron-related genes.
• Differential gene expression analysis during the reaggregation of Halisarca dujardini.

Main Results:

• Identified heme biosynthesis enzymes and transport globins (neuroglobin and androglobin) in sponges.
• Observed higher evolutionary rates in sponge globins compared to heme synthesis enzymes.
• Found increased expression of iron-regulatory protein 1 (IRP1), BCL2, NFκB, ferritin (FTH1), and neuroglobin (NGB) during reaggregation, alongside increased mitochondrial density.

Conclusions:

• Sponges possess a complex iron regulation system involving IRP1, ferritin, and globins, contributing to their unique structural plasticity.
• The identified iron metabolic pathways provide insights into general mechanisms of multicellular development and regeneration.
• Evolutionary analysis reveals distinct rates of change for different components of the iron metabolism pathway.