Development of a novel simplified Q-system with integrated temporal expression control.

Area of Science:

• Genetics and Molecular Biology
• Developmental Biology
• Gene Regulation

Background:

• Bimodal gene expression systems are crucial for understanding gene, cell, and organ function.
• Temporal control of gene expression has been a significant limitation in these systems.
• The Q-system, utilizing the QF2 transcription factor, is widely used in model organisms like Drosophila.

Purpose of the Study:

• To incorporate temperature-sensitive intein modules into the QF2 transcription factor for temporal control.
• To develop a novel, temporally regulated gene expression system for broader applicability.
• To overcome limitations of existing gene expression systems, particularly regarding temporal regulation.

Main Methods:

• Integration of temperature-sensitive intein modules with distinct temperature profiles into QF2.
• Testing the QF2_INT^ts activators in Drosophila larvae and adult flies under varying temperature conditions.
• Utilizing QUAS reporters to monitor gene expression driven by the QF2_INT^ts system.

Main Results:

• Temperature-sensitive QF2_INT^ts activators enable precise temporal control of QUAS reporter gene expression in Drosophila.
• Permissive temperatures (18°C-25°C) activate QF2, driving reporter expression, while restrictive temperatures (23°C-30°C) inactivate it.
• The system allows for both activation and deactivation of gene expression by switching between temperature conditions.
• Animals expressing QUAS-Kir2.1 show viability under restrictive conditions, with temperature shifts leading to lethality or paralysis.

Conclusions:

• The intein-based Q-system provides a robust and simplified method for temporal gene expression regulation, eliminating the need for drug-dependent suppressors.
• QF2_INT^ts drivers offer significant advantages over the GAL4 system and can be implemented in diverse organisms, including insects and zebrafish.
• This technology facilitates the study of gene and cell function across developmental stages and in various species, including disease vectors and poikilotherm vertebrates.