Phenotypes Associated with This Genotype

Genotype
MGI:2172761

• Allelic Composition: Phox2b^tm1Jbr/Phox2b^tm1Jbr
• Genetic Background: Not Specified

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

mortality/aging

lethality throughout fetal growth and development, complete penetrance ( J:63723 )

• die shortly after midgestation; no homozygotes survive to E18.5 and fewer homozygotes are recovered at E13.5

• prenatal lethality phenotype of homozygous mutant mice can be rescued by supplying them with noradrenergic agonists and these mice survive to around E18.5-birth

embryonic lethality during organogenesis, incomplete penetrance ( J:63723 )

• die shortly after midgestation; no homozygotes survive to E18.5 and fewer homozygotes are recovered at E13.5

homeostasis/metabolism

abnormal noradrenaline level ( J:55391 , J:63723 )

• lack noradrenaline synthesis (J:55391)

• noradrenergic centers in the brain are absent in mutants that are supplied with noradrenergic agonist and survive to E18.5 (J:55391)

nervous system

abnormal autonomic nervous system morphology ( J:55391 )

• all autonomic ganglia fail to form properly and degenerate

abnormal enteric ganglia morphology ( J:55391 )

• absence of the enteric components of the autonomic nervous system at E13.5

• the foregut contingent of enteric nervous system degenerates by apoptosis between E10.5 and E13.5 and migration of enteric neural precursors towards the mid- and hindgut is arrested at the stomach

abnormal parasympathetic ganglion morphology ( J:55391 )

• absence of parasympathetic ganglia at E13.5

abnormal sympathetic ganglion morphology ( J:55391 )

• absence of sympathetic ganglia at E13.5

• neural-crest derived sympathetic progenitors aggregate at the sites of sympathetic ganglion formation at E10.5, but subsequently fail to proliferate and/or degenerate

abnormal area postrema morphology ( J:86516 )

• the area postrema never forms in mutants that are supplied with a noradrenergic agonist so that they can survive beyond E10.5

abnormal medulla oblongata morphology ( J:86516 )

• the central target of visceral sensory ganglia, the nucleus of the solitary tract, never forms in mutants that are supplied with a noradrenergic agonist so that they can survive beyond E10.5

abnormal locus ceruleus morphology ( J:63723 )

• locus coeruleus is absent in mutants that are supplied with noradrenergic agonist and survive to E18.5

abnormal motor neuron morphology ( J:55391 , J:60832 )

• exhibit defects in the differentiation of branchiomotor neurons in the rhombencephalon (J:55391)

• visceral and branchial motor neurons are absent in the hindbrain of embryos supplied with a noradrenergic agonist so that they can survive to E18.5 (J:60832)

• precursors of branchial motor and visceral motor neurons arise in embryos but they fail to put out axons, to emigrate from the region and to differentiate (J:60832)

• exhibit increased cell death of motor neuronal precursors (J:60832)

• nucleus ambiguus is absent in mutants that are supplied with noradrenergic agonist and survive to E18.5 (J:60832)

abnormal cranial ganglia morphology ( J:55391 , J:86516 )

• the three cranial sensory ganglia that are part of the autonomic reflex circuits are atropic in mid-gestation embryos (J:55391)

• the three epibranchial placode-derived visceral sensory ganglia (geniculate, petrosal, and nodose) degenerate (J:86516)

abnormal geniculate ganglion morphology ( J:55391 , J:86516 )

• the epibranchial placode-derived visceral sensory ganglia of the VIIth cranial nerve are atrophic in mid-gestation embryos (J:55391)

• degenerates until visually absent by E16.5 in mutants that are supplied with a noradrenergic agonist so that they can survive beyond E10.5 (J:86516)

abnormal glossopharyngeal ganglion morphology ( J:55391 )

• the epibranchial placode-derived visceral sensory ganglia of the IXth cranial nerves are atrophic in mid-gestation embryos

abnormal petrosal ganglion morphology ( J:86516 )

• degenerates until visually absent by E16.5 in mutants that are supplied with a noradrenergic agonist so that they can survive beyond E10.5

abnormal vagus ganglion morphology ( J:55391 )

• the epibranchial placode-derived visceral sensory ganglia of the Xth cranial nerves are atrophic in mid-gestation embryos

abnormal nodose ganglion morphology ( J:86516 )

• degenerates until visually absent by E16.5 in mutants that are supplied with a noradrenergic agonist so that they can survive beyond E10.5

abnormal cranial nerve morphology ( J:60832 )

absent facial nerve ( J:60832 )

• facial nerve (CN-VII) is absent in mutants that are supplied with a noradrenergic agonist and are able to survive to E18.5

absent trigeminal nerve ( J:60832 )

• trigeminal nerve (CN-V) is absent in mutants that are supplied with a noradrenergic agonist and are able survive to E18.5

abnormal vagus nerve morphology ( J:60832 )

• the dorsal motor nucleus of the vagus nerve (CN-X) is absent in mutants that are supplied with a noradrenergic agonist and are able to survive to E18.5

cardiovascular system

abnormal carotid body morphology ( J:86516 )

• carotid body degenerates in mutants that are supplied with a noradrenergic agonist so that they can survive beyond E10.5

blood vessel congestion ( J:63723 )

• 3 of 8 embryos exhibit signs of vascular congestion around the time of death (about E13.5)