Novel Alternative Splice Variants of Mouse Cdk5rap2

Area of Science:

• Neurodevelopmental science
• Stem cell biology
• Genetics

Background:

• Autosomal recessive primary microcephaly (MCPH) is a rare neurodevelopmental disorder causing reduced brain volume and intellectual disability.
• A key model suggests MCPH arises from defects in neural stem cell proliferation and differentiation.
• Mutations in the CDK5RAP2 gene are a known cause of MCPH.

Purpose of the Study:

• To investigate the pathomechanism of MCPH.
• To characterize the role of CDK5RAP2 in brain development.
• To understand why a generated mouse model lacking a microcephaly phenotype did not exhibit the expected condition.

Main Methods:

• Generation of a conditional Cdk5rap2 LoxP/hCMV Cre mutant mouse model.
• Phenotypic analysis of the mutant mice.
• Molecular analysis to identify genetic factors potentially explaining the lack of phenotype.

Main Results:

• The conditional Cdk5rap2 mutant mice did not display a microcephaly phenotype.
• Previously unknown splice variants of the Cdk5rap2 gene were identified.
• These novel splice variants are implicated in the absence of microcephaly in the studied mice.

Conclusions:

• The pathomechanism of MCPH is more complex than previously understood.
• Novel splice variants of CDK5RAP2 play a role in regulating brain size and may mitigate MCPH.
• Further research is needed to fully elucidate the function of these splice variants in neurodevelopment.