• CD171, also known as L1CAM or L1, is a transmembrane glycoprotein. It is a 200-220 kDa neuronal cell adhesion molecule and a member of the L1 protein family belonging to the immunoglobulin superfamily.
• This cell adhesion molecule plays an important role in nervous system development, including neuron-neuron adhesion, signal transduction, axon guidance, cell migration and differentiation. CD171 also has a strong implication in treatment-resistant cancers. Mutations in the gene cause three X-linked neurological syndromes known by the acronym CRASH (corpus callosum hypoplasia, retardation, aphasia, spastic paraplegia and hydrocephalus). Alternative splicing of a neuron-specific exon is thought to be functionally relevant.

Gene targeting strategy for B-hL1CAM mice plus. The exons 1-29 of mouse L1cam gene that encode the whole molecule (ATG to STOP codon), including 5’UTR and 3’UTR are replaced by human counterparts in B-hL1CAM mice plus. The human L1CAM expression is driven by endogenous human L1CAM promoter, while mouse L1cam gene transcription and translation will be disrupted.

Strain specific L1CAM expression analysis in homozygous B-hL1CAM mice plus by flow cytometry. Brain were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hL1CAM mice plus (H/H), and analyzed by flow cytometry with species-specific anti-CD171/L1CAM antibody (R&D, FAB5674P; Invitrogen, 17-1719-41). mCD171/L1CAM was exclusively detectable in wild-type C57BL/6 mice, hCD171/L1CAM was exclusively detectable in homozygous B-hL1CAM mice plus.