Comparative Transcriptome Sequencing Analysis Revealed Key Pathways and Hub Genes Related to Gill Raker Development...

Area of Science:

• Developmental Biology
• Evolutionary Biology
• Ecology
• Genomics

Background:

• Silver carp (Hypophthalmichthys molitrix) exhibit significant gill raker morphological changes linked to diet and development.
• The molecular underpinnings of these crucial gill raker adaptations remain largely unknown.

Purpose of the Study:

• To investigate the molecular mechanisms behind silver carp gill raker development.
• To correlate structural changes with gene expression patterns during early life stages.

Main Methods:

• Utilized scanning electron microscopy (SEM) for structural analysis of gill rakers at five developmental stages (6-60 days post-hatching).
• Performed comparative transcriptomics to identify differentially expressed genes (DEGs) across developmental stages.
• Employed Gene Set Enrichment Analysis (GSEA) to identify enriched pathways and gene families.

Main Results:

• SEM showed gill rakers evolving from sparse protrusions to a dense, sieve-like mesh.
• Transcriptomics identified 10,184 DEGs, enriched in Focal Adhesion, ECM-Receptor Interaction, and PI3K-Akt pathways.
• Early development (6 vs. 15 dph) showed coordinated upregulation of collagen and integrin genes.

Conclusions:

• This study elucidates the molecular basis of gill raker development in silver carp.
• Identified key genetic pathways and gene families (collagens, integrins) crucial for filter-feeding structure formation.
• Provides insights into the genetic regulation of morphological adaptation for ecological niche specialization.