Multiple cis-regulatory modules ensure robust tup/islet1 function in dorsal muscle identity specification

Area of Science:

• Developmental Biology
• Molecular Genetics
• Drosophila melanogaster research

Background:

• Precise spatial and temporal transcriptional control is essential for functional muscle development in Drosophila.
• Cis-regulatory modules (CRMs) integrate transcription factor inputs to fine-tune gene expression during myogenesis.
• The LIM-homeodomain transcription factor Tup is a key regulator of dorsal muscle development.

Purpose of the Study:

• To investigate the transcriptional regulation of the Tup gene.
• To elucidate the role of multiple CRMs in controlling Tup expression during myogenesis.

Main Methods:

• CRISPR-Cas9-mediated deletion of CRMs.
• Transcriptional analyses.
• Detailed morphological analyses of muscle development.

Main Results:

• Tup expression is regulated by multiple, redundantly functioning CRMs in dorsal muscles.
• Mesodermal Tup CRMs act sequentially and differentially in dorsal muscles, heart cells, and alary muscles.
• Deletion of late-acting CRMs leads to muscle identity shifts, defective patterning, and misalignments.

Conclusions:

• CRM-mediated autoregulation and redundancy are crucial for robust and precise Tup expression during muscle development.
• Coordination of multiple CRMs ensures proper muscle identity and function.
• Findings provide insights into gene regulatory networks governing myogenesis.