Single-cell transcriptomics defines keratinocyte differentiation in avian scutate scales

Area of Science:

• Developmental Biology
• Molecular Biology
• Genomics

Background:

• Skin appendage growth, including avian scales, relies on epidermal keratinocyte differentiation.
• Understanding scale development is key to avian skin biology.

Purpose of the Study:

• To investigate keratinocyte differentiation in avian scutate scales.
• To define gene expression programs underlying scale and interscale epidermis formation.
• To identify conserved keratinocyte differentiation genes.

Main Methods:

• Single-cell transcriptomics on chick leg skin cells.
• Identification of distinct keratinocyte populations.
• Antibody generation and immunostaining for KRT9LC2.

Main Results:

• Two differentiated keratinocyte populations identified: scale-forming (cysteine-rich keratins, beta-keratins) and interscale epidermis-forming (cysteine-poor keratins).
• KRT9LC2 expression confirmed in scutate scale suprabasal layers.
• Chicken skin differentiation shows similarities to human skin, including conserved gene pathways.

Conclusions:

• Gene expression programs for avian scutate scales and interscale epidermis are defined.
• Evolutionarily conserved keratinocyte differentiation genes were identified.
• This research provides insights into avian skin appendage development and evolution.