Dand5 is involved in zebrafish tailbud cell movement

Area of Science:

• Developmental Biology
• Genetics
• Cell Biology

Background:

• Vertebrate development involves symmetry breaking in the left-right organizer (LRO) for asymmetric organ patterning.
• Maintaining somite symmetry is crucial for correct musculature and vertebrae development.
• The gene dand5 is a known regulator of left-right (LR) asymmetry in vertebrates.

Purpose of the Study:

• To investigate how left-right signals influence zebrafish somite cell precursor behavior.
• To identify and characterize Non-KV Sox17:GFP+ Tailbud Cells (NKSTCs) and their role in somite formation.
• To elucidate the function of dand5 in regulating asymmetric cell migration during somite development.

Main Methods:

• Live imaging of zebrafish embryos.
• Fate mapping studies in wildtype and dand5 homozygous mutant embryos.
• Analysis of NKSTC migration patterns and somite integration.

Main Results:

• A population of NKSTCs was identified, originating posterior to the LRO and migrating anteriorly to contribute to somites.
• NKSTCs exhibit left-right alternating migration patterns, with preferential integration into left-side somites in wildtype embryos.
• In dand5-/- mutants, this asymmetric migration is abolished, with NKSTC exit from the posterior cluster becoming bilaterally synchronous.

Conclusions:

• Dand5 plays a critical role in regulating the asymmetric exit of NKSTCs from a posterior cell cluster.
• This study reveals a novel function for Dand5 in coordinating left-right signaling with somite specification.
• Disruption of Dand5 function affects myogenic factor expression and overall tail size, highlighting its importance in axial development.