Mouse Genome Informatics
ot
    Arxtm1Kki/Y
involves: 129P2/OlaHsd * C57BL
Key:
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• male hemizygotes are born at normal Mendelian ratios at E19.5 but die within 12 hrs after birth

nervous system
• at E13.5, hemizygotes exhibit a nearly normal migration of neuroepithelial cells in the cortical plate, except for some projection neurons
• at E14.5, hemizygotes display loss of direct migration of interneurons from the medial ganglionic eminence to the cortical intermediate zone
• in contrast, the migration of interneurons from the medial ganglionic eminence to the cortical subventricular zone via the lateral ganglionic eminence appears unchanged
• hemizygotes display abnormalities in neuronal proliferation, interneuronal migration and differentiation of the embryonic forebrain
• at E19.5, hemizygotes exhibit dysgenesis of the hippocampus
• at E19.5, only a small number of neurons of detected in the marginal zone
• in hemizygotes, glutaminergic neurons are abnormally distributed in layers II-V of the cortical plate instead of being located in layer V as in wild-type mice
• at E19.5, the cortical plate is thinner than normal
• at E12.5 and E14.5, the neocortical ventricular zone is thinner and contains fewer BrdU-positive cells than in wild-type mice
• hemizygotes have small brains
• at E19.5, the third ventricle is expanded due to partial dysgenesis of the thalamus
• at E18.5, thalamocortical axons to the internal capsule appear elongated via an ectopic pathway located in the vicinity of the amygdala
• at E12.5, hemizygotes display a deficiency in the thalamic eminence and part of the ventral thalamus
• as a result, the anterior medial thalamic nuclei and most of the central medial thalamic nuclei are lost at E19.5
• at E19.5, most of the central medial thalamic nuclei are lost
• at E19.5, hemizygotes display morphological abnormalities in the dorsal and ventral telencephalon
• at E19.5, hemizygotes display dysgenesis of the CA3 field
• at E19.5, hemizygotes display dysgenesis of the dentate gyrus
• at E19.5, the hippocampal fimbria are lost
• at E14.5, the embryonic neocortex is thinner than normal as a result of reduced proliferation of neuroepithelial cells in the entire neocortical ventricular zone
• the left and right olfactory bulbs are positioned with a wide interspace
• hemizygotes have small olfactory bulbs
• at E18.5, hemizygotes display many aberrant nerve fiber tracts, including the passage of thalamocortical axons through the amygdala
• at E19.5, the corpus callosum appears abnormal with a shortened anterioposterior axis
• at E19.5, the hippocampal commissure is lost
• in hemizygotes, glutaminergic neurons are abnormally distributed in layers II-V of the cortical plate instead of being located in layer V as in wild-type mice

endocrine/exocrine glands
• hemizygotes display hypoplasia of the seminal vesicles
• at E14.5, expression of the Leydig cell marker Hsd3b1 is severely reduced in the interstitial region of mutant testes, indicating a block in Leydig cell differentiation
• this effect is variable among individual mutant mice
• hemizygotes display seminiferous tubules of increased diameter relative to wild-type mice
• hemizygotes have small testes

reproductive system
• hemizygotes display hypoplasia of the seminal vesicles
• at E14.5, expression of the Leydig cell marker Hsd3b1 is severely reduced in the interstitial region of mutant testes, indicating a block in Leydig cell differentiation
• this effect is variable among individual mutant mice
• hemizygotes display seminiferous tubules of increased diameter relative to wild-type mice
• hemizygotes have small testes

cellular
• at E13.5, hemizygotes exhibit a nearly normal migration of neuroepithelial cells in the cortical plate, except for some projection neurons
• at E14.5, hemizygotes display loss of direct migration of interneurons from the medial ganglionic eminence to the cortical intermediate zone
• in contrast, the migration of interneurons from the medial ganglionic eminence to the cortical subventricular zone via the lateral ganglionic eminence appears unchanged

Mouse Models of Human Disease
OMIM IDRef(s)
Lissencephaly, X-Linked, 2; LISX2 300215 J:79871