A CRISPR-based screen for Hedgehog signaling provides insights into ciliary function and ciliopathies

Area of Science:

• Cell Biology
• Developmental Biology
• Genetics

Background:

• Primary cilia are crucial for embryonic development and Hedgehog signaling.
• Dysregulation of primary cilia leads to a class of genetic disorders known as ciliopathies.
• Understanding the genetic basis of ciliopathies is essential for developing therapeutic strategies.

Purpose of the Study:

• To develop and validate a functional genomic screen for identifying genes involved in ciliary Hedgehog signaling.
• To uncover novel components of ciliary structures and their roles in centriole maintenance.
• To apply the screen for unbiased classification of ciliopathies and identify their genetic underpinnings.

Main Methods:

• Genome-wide CRISPR-mediated gene disruption coupled with antibiotic-based selection for Hedgehog-responsive cells.
• Functional genomic screening to robustly identify factors essential for ciliary signaling.
• Characterization of identified 'hit' genes and their associated protein complexes.

Main Results:

• The CRISPR screen accurately identified genes critical for ciliary signaling with high specificity.
• Novel ciliary structure components, including a delta-tubulin and epsilon-tubulin complex, were discovered and linked to centriole maintenance.
• The screen revealed that many congenital heart disorders result from the loss of ciliary signaling.

Conclusions:

• The developed CRISPR screen is a versatile platform for dissecting signaling pathways and analyzing ciliary function.
• This study provides a systematic approach to understanding ciliopathies and their genetic causes.
• The findings highlight the significant role of primary cilia in embryonic development and their connection to congenital heart defects.