Cre-mediated site-specific recombination in zebrafish embryos

Area of Science:

• Genetics
• Molecular Biology
• Developmental Biology

Background:

• Cre-mediated recombination is crucial for manipulating the mouse genome.
• Applying this tool to zebrafish genetics could significantly advance research by enabling conditional gene expression and chromosomal alterations.

Purpose of the Study:

• To investigate the feasibility of using the HSP70 promoter to inducibly control Cre recombinase expression in zebrafish.
• To assess the efficiency and timing of Cre-mediated recombination following heat shock induction.
• To evaluate the viability and fertility of transgenic zebrafish expressing the Cre-EGFP fusion protein.

Main Methods:

• Constructing a transgenic zebrafish line expressing an enhanced green fluorescent protein (EGFP)-Cre fusion protein under the control of the HSP70 promoter.
• Inducing Cre expression via heat shock and assessing recombination efficiency in both injected plasmids and stably inherited transgenes.
• Monitoring the viability and reproductive capacity of transgenic fish post-induction.

Main Results:

• The HSP70 promoter successfully drove inducible expression of the EGFP-Cre fusion protein.
• Cre-mediated recombination was observed as early as 2 hours post-heat shock induction in both transient and stable transgenes.
• Transgenic zebrafish exhibited normal viability and fertility, with both males and females being fertile after EGFP-Cre expression induction.

Conclusions:

• The HSP70 promoter provides a reliable method for inducible Cre-mediated recombination in zebrafish.
• This system allows for conditional gene expression and genetic manipulation in zebrafish, enhancing their utility in genetic studies.
• Cre-mediated recombination is a viable and effective tool for advancing zebrafish genetics research.