Six3-CreERT2 (Six3+/-) knock-in/knock-out mice have cre/ERT2 cDNA replacing part of exon 1 of the sine oculis-related homeobox 3 (Six3) gene. Six3 encodes a transcription factor that is required for the development of the eye and the formation of the telencephalon. Mutations in Six3 cause defects such as cyclopia and microforms, and account for 1.3% of all cases of Holoprosencephaly (HPE). HPE is the most common forebrain malformation, and is characterized by an incomplete separation of the cerebral hemispheres. Six3+/- embryos contain approximately half of the amount of Six3 transcripts present in wild-type littermates. Heterozygous mice are viable and fertile, while homozygous mice are embryonic lethal. When this mouse strain was backcrossed once onto a C57BL/6 genetic background, 16% of the F1 Six3+/- embryos exhibit HPE-like phenotypes, including absence of the cartilage nasal septum, the septum, and the corpus callosum. They also exhibit a fusion defect in the secondary palate. When further backcrossed onto the C57BL/6 background, more than 85% of the F3 Six3+/- embryos exhibit HPE-like phenotypes that were indistinguishable from those of Six3+/ki knock-out embryos on a mixed background. Due to the background-dependent manner that HPE is displayed in these mice, the donating investigator suggests maintaining these mice on an outbred background.

Use of MICE by companies or for-profit entities requires a no-fee JAX Leap License prior to shipping.

Six3-CreERT2 (Six3+/-) knock-in/knock-out mice have cre/ERT2 cDNA replacing part of exon 1 of the sine oculis-related homeobox 3 (Six3) gene. They are useful for studying Holoprosencephaly (HPE).

Typically mice are recovered in 12-16 weeks. Contact Customer Service to place an order or for more information.

<a target="_blank" href="https://www.jax.org/jax-mice-and-services/customer-support" rel="noreferrer">Contact Customer Service</a> for more information.