A single-cell transcriptomic atlas of inner ear morphogenesis in zebrafish

Area of Science:

• Developmental Biology
• Genomics
• Otolaryngology

Background:

• The inner ear comprises sensory patches, semicircular canals for rotation detection, and the endolymphatic duct/sac for pressure homeostasis.
• Understanding the cellular and molecular mechanisms of inner ear development is crucial but largely unknown.

Purpose of the Study:

• To elucidate the cell states and transcriptional landscape during inner ear development.
• To identify molecular markers and genetic pathways involved in inner ear morphogenesis.

Main Methods:

• Single-cell RNA sequencing was performed on wild-type zebrafish embryos and *lmx1bb* mutants.
• Comparative transcriptomic analysis was used to distinguish cell states and identify key genes.

Main Results:

• Identified *ccn1l1* as the earliest marker for semicircular canal formation.
• Discovered novel genes like *smtnb* in the endolymphatic sac, suggesting a role for tissue contraction.
• Found parallel gene sets for sensory patches and conserved cell-cycle pausing in canals and sacs.

Conclusions:

• This study provides a comprehensive transcriptional atlas of the developing inner ear.
• New molecular insights into inner ear morphogenesis and function are presented.
• Identified novel gene targets for future research on inner ear development and disorders.