Zebrafish prion protein PrP2 controls collective migration process during lateral line sensory system development

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Prion protein's physiological role remains unclear due to lack of severe defects in knockout mice.
• Zebrafish prion genes PrP1 and PrP2 are implicated in embryonic development.

Purpose of the Study:

• Investigate the role of PrP2 in the development of the zebrafish posterior lateral line.
• Determine PrP2's function in sensory organ formation and nerve development.

Main Methods:

• Morpholino knockdown and PrP2 targeted inactivation in zebrafish.
• Analysis of posterior lateral line development, including axonal outgrowth, primordium migration, and neuromast deposition.
• Assessment of cell adhesion molecules (E-cadherin, ß-catenin) and hair cell differentiation.

Main Results:

• PrP2 deficiency caused defects in posterior lateral line nerve axonal outgrowth and primordium migration.
• Reduced neuromast deposition and abnormal rosette formation were observed in PrP2 morphants and mutants.
• Mis-localization of E-cadherin and ß-catenin indicated impaired cell adhesion, affecting hair cell differentiation and neuromast function.
• Alterations in posterior lateral line nerve myelination were noted at later developmental stages.

Conclusions:

• PrP2 plays a crucial role in the collective migration and organization of the posterior lateral line primordium.
• PrP2 is essential for neuromast formation, hair cell differentiation, and functional sensory development.
• The findings suggest a significant role for prion protein in cell adhesion processes during development.