Loss of ctnnd2b affects neuronal differentiation and behavior in zebrafish

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Delta-catenin (CTNND2) is an adhesive junction protein linked to neurodevelopmental disorders.
• The human CTNND2 gene is located in a region deleted in Cri-du-chat syndrome.
• Heterozygous CTNND2 loss is associated with autism, schizophrenia, and intellectual disability.

Purpose of the Study:

• To investigate the impact of heterozygous loss of delta-catenin specifically in zebrafish (ctnnd2b) on embryonic development and adult behavior.
• To identify specific neuronal abnormalities in the developing zebrafish brain.
• To analyze behavioral changes in zebrafish larvae and adults with ctnnd2b loss.

Main Methods:

• Zebrafish model organism utilized for studying gene function.
• Observation of embryonic development and neuronal subtype organization (e.g., isl1, GABA).
• Time-lapse imaging to analyze neuron specification and distribution.
• Behavioral analysis of larval and adult zebrafish swimming patterns.

Main Results:

• Observed disorganization of neuronal subtypes in the developing zebrafish forebrain.
• Identified ectopic isl1-expressing cells and reduced GABA-positive neurons in the optic recess region.
• Time-lapse analysis revealed increased specification of Isl1:GFP neurons.
• Heterozygous ctnnd2b zebrafish exhibited increased swimming activity in both larval and adult stages.

Conclusions:

• Zebrafish ctnnd2b plays a crucial role in the differentiation of specific neuronal subtypes within the vertebrate brain.
• Disruption of ctnnd2b impacts neuronal development, leading to observable behavioral changes.
• These findings contribute to understanding the genetic basis of neurodevelopmental disorders associated with CTNND2.