Daxx Conditional Knockout mouse models

Death domain associated protein, encoded by Daxx and orthologous to human DAXX, is a dedicated histone chaperone that captures the H3.3 to H4 dimer through variant-specific recognition of alanine 87, isoleucine 89, and glycine 90, then hands it to ATRX for deposition at telomeres, pericentromeric repeats, and endogenous retroviral elements. SUMO-interacting motifs additionally localize it to PML nuclear bodies, where it sequesters transcription factors and modulates apoptotic signaling. Inactivating mutations co-occur with ATRX loss in pancreatic neuroendocrine tumors and drive alternative lengthening of telomeres through defective heterochromatin maintenance and replication stress at repeats. Constitutive deletion causes embryonic lethality near E9.5 with widespread apoptosis, so conditional alleles paired with lineage or tamoxifen-inducible Cre are essential for adult tumor work. ATRX cannot substitute for chaperone activity, making compound analysis informative rather than redundant. Align allele class with telomere maintenance, retroelement derepression, or tumor latency as the intended readout.

A floxed Daxx allele paired with Cre gives spatial control that whole body knockouts cannot offer. People use it to separate developmental roles from adult homeostasis, to model somatic mutations, and to match disease that begins in one organ.