Cytokeratin 8 is a suitable epidermal marker during zebrafish development

Area of Science:

• Molecular Biology
• Developmental Biology
• Zebrafish Genetics

Background:

• Cytokeratins are intermediate filament proteins essential for epithelial cell cytoskeleton integrity.
• Cytokeratin 8 (K8) is a type II cytokeratin found in simple epithelia of various vertebrates.
• Understanding K8 expression in zebrafish (Danio rerio) can provide insights into epithelial development and differentiation.

Purpose of the Study:

• To clone and characterize the zebrafish homologous cytokeratin 8 (zf-K8) cDNA.
• To analyze the gene expression patterns of zf-K8 during zebrafish embryonic development and in adult tissues.
• To evaluate the potential of zf-K8 as an epidermal marker in zebrafish ontogenesis.

Main Methods:

• Cloning of zebrafish cytokeratin 8 (zf-K8) cDNA.
• Gene expression analysis using mRNA detection techniques.
• Comparative analysis of zf-K8 expression across different developmental stages and adult tissues.

Main Results:

• Maternal inheritance of zf-K8 mRNA observed, present from oocyte to cleavage stage embryo.
• Post-mid blastula transition, zf-K8 is expressed in all surface cells (enveloping layer, periderm) and specific deep cells (intestinal progenitors).
• Strong zf-K8 expression detected in developing pectoral fins during later embryonic stages and in adult stratified skin and differentiated fins, unlike other vertebrates.

Conclusions:

• Zebrafish cytokeratin 8 (zf-K8) exhibits unique expression patterns in adult tissues, including stratified epithelia.
• zf-K8 mRNA is maternally inherited and dynamically expressed during zebrafish embryogenesis.
• The distinct expression profile of zf-K8 suggests its utility as a reliable epidermal marker throughout zebrafish ontogenesis.