High impact information on Otx1

• The spatial and temporal patterns suggest that Otx1 may play a role in the specification or differentiation of neurons in the deep layers of the cerebral cortex [1].
• Whole-mount in situ hybridization of mouse embryos from 9.5 to 11.5 dpc revealed strong expression of Otx3 mRNA in the diencephalon, mesencephalon, metencephalon, myelencephalon, and developing eye, indicating an expression pattern largely overlapping but distinct from those of Otx1 and Otx2 [2].
• These results suggest that ventricular cells actively sequester Otx1 in the cytoplasm, either by preventing nuclear import or by promoting a balance of export over import signals [3].
• Deletion analysis reveals that Otx1 is imported actively into cell nuclei, that the N-terminus of Otx1 is necessary for nuclear import, and that a putative nuclear localization sequence within this domain is sufficient to direct nuclear import in a variety of cell lines [3].
• In contrast, GFP-Otx1 fusion proteins that contain the N-terminus are retained in the cytoplasm of cortical progenitor cells, mimicking the distribution of Otx1 in vivo [3].

Biological context of Otx1

• Knockout Otx1 mice present a microcephalic phenotype mainly due to reduced deep neocortical layers and spontaneous recurrent seizures [4].
• The pyramidal neurons recorded in Otx1-/- mice responded to near-threshold electrical stimulation of the underlying white matter, with aberrant polysynaptic excitatory potentials often leading to late action potential generation [4].

Associations of Otx1 with chemical compounds

• Potentially epileptogenic dysfunction of cortical NMDA- and GABA-mediated neurotransmission in Otx1-/- mice [4].

Analytical, diagnostic and therapeutic context of Otx1

• To explore the molecular underpinnings of pattern formation in layered regions of the CNS, we have characterized the patterns of expression of two homeodomain genes, Otx1 and Otx2, by in situ hybridization during embryonic and postnatal development in the rat [1].

References