Dually inducible TetON systems for tissue-specific conditional gene expression in zebrafish

Area of Science:

• Molecular Biology
• Zebrafish Genetics
• Gene Expression Regulation

Background:

• Spatial and temporal control of gene expression is crucial for developmental biology and adult model organism research.
• Existing tetracycline-inducible (Tet) systems have limitations in specificity and leakiness.

Purpose of the Study:

• To develop and characterize two novel, modified dually inducible TetON systems for precise, tissue-specific gene expression control in zebrafish.
• To evaluate the performance, leakiness, reversibility, and tunability of these new systems.

Main Methods:

• Construction of two TetON systems: TetA-GBD (TetActivator fused to mutated glucocorticoid receptor) and TetA-EcR (TetActivator fused to Ecdysone receptor).
• Testing induction with specific ligands (doxycycline, dexamethasone, tebufenozide) in transgenic zebrafish lines.
• Assessing gene expression control in different tissues (heart, CNS) and life stages (embryos, adults).

Main Results:

• Both TetA-GBD and TetA-EcR systems demonstrated strong induction of tetracycline-responsive promoters with minimal leakiness compared to classical TetActivators.
• Tissue-specific gene expression was achieved by combining transgenic lines.
• Induction was found to be reversible and tunable by drug dosage.
• The TetA-EcR system showed improved sensitivity and avoided potential dexamethasone side effects.

Conclusions:

• Modified dually inducible TetON systems provide highly specific and tightly controlled conditional gene expression in zebrafish.
• These systems are versatile tools for research in zebrafish embryos and adults, offering reversibility and tunability.
• The TetA-EcR system presents an advantageous alternative due to enhanced sensitivity and reduced side effects.