In this strain, a neomycin resistance (neo) cassette replaces exon 3 of the p21 protein (Cdc42/Rac)-activated kinase 5 (Pak5, formerly Pak7) gene, abolishing gene expression. Homozygotes are viable, fertile, normal in size, and do not display any gross physical abnormalities. Pak5 is a member of the group B family of PAK serine/threonine kinases and is expressed in the cortex, striatum, hypothalamus, cerebellum, and hippocampus. It is involved in neuronal growth and filopodia formation. The absence of a significant aberrant phenotype in these mice may be due to the compensatory actions of Pak6 (p21 protein (Cdc42/Rac)-activated kinase 6). When maintained on a background also lacking Pak6 activity, these mice have impaired cognitive function and deficits in learning and memory retention. These mice may be useful for studying learning, memory, and locomotion.
