Regulatory Divergence among Beta-Keratin Genes during Bird Evolution

Area of Science:

• Evolutionary developmental biology
• Genomics
• Molecular biology

Background:

• Feathers exhibit high diversity due to β-keratin gene evolution.
• Regulatory mechanisms driving β-keratin gene expression diversification remain largely unknown.

Purpose of the Study:

• To investigate regulatory changes contributing to feather β-keratin gene expression diversification.
• To identify transcription factors (TFs) regulating β-keratin genes in different feather parts.

Main Methods:

• Transcriptome analysis of five chicken feather regions.
• Inference of β-keratin enriched co-expression modules and TF-target gene predictions.
• In vitro validation of predicted TF-target gene relationships.

Main Results:

• 262 TF-target gene relationships predicted, with 56 TFs regulating 91 β-keratin genes.
• Identified 26 major regulators of β-keratin genes using TF enrichment and expression correlation.
• Feather β-keratin genes exhibit chromosome-wise regulation distinct from scale/claw β-keratin genes.

Conclusions:

• Regulatory divergence of β-keratin genes contributes to feather structural differences.
• Feather β-keratin genes recruited distinct or chromosome-specific regulators after gene expansion.
• This study elucidates the regulatory evolution of feather β-keratin genes compared to scale and claw genes.