Phenotypes Associated with This Genotype

Genotype
MGI:3762504

• Allelic Composition: Phox2b^{tm1(Phox2a)Mist}/Phox2b^{tm1(Phox2a)Mist}
• Genetic Background: involves: 129S4/SvJae

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:126634 )

• mice die at E13.5 similar to Phox2b^tm1Jbr homozygotes

• treatment of mothers with noradrenergic agonists rescues pup survival up to birth

nervous system

abnormal nervous system morphology ( J:126634 )

• authors state that mice exhibit a similar to identical phenotype as that observed in Phox2b^tm1Jbr homozygotes

• motorneuron differentiation is partially rescued up to the level of the caudal hindbrain

abnormal enteric nervous system morphology ( J:126634 )

• the enteric nervous system is absent as in Phox2b^tm1Jbr homozygotes

abnormal parasympathetic ganglion morphology ( J:126634 )

• similar to Phox2b^tm1Jbr homozygotes, mice exhibit a noradrenergic deficit

small facial motor nucleus ( J:126634 )

• at later stages of embryonic development, the facial motor nucleus is smaller than in wild-type mice and located in a more anterior position

abnormal locus ceruleus morphology ( J:126634 )

• despite an early partial rescue of the noadrenergic deficit, at E 13.5 no locus ceruleus (LC) neurons are present

• however, differentiation of a subpopulation of LC neurons is rescued compared to in Phox2b^tm1Jbr homozygotes

abnormal motor neuron morphology ( J:126634 )

• disruptions in brachio-viscero-motor neuron differentiation observed in Phox2b^tm1Jbr homozygotes are partially rescued but proper migration of facial brachimotor neurons is still defective

abnormal cranial ganglia morphology ( J:126634 )

• unlike in Phox2b^tm1Jbr homozygotes, peripherin+ and Ret+ cells are still present at E16.5 in the ninth and tenth cranial nerve complex although they are less densely packed than in wild-type mice

• atrophy of the ninth and tenth cranial nerve complex is about 72% of the surface area measured

• mice lack dorsal motor nuclei of the vagus and noradrenergic neurons

small trigeminal ganglion ( J:126634 )

• at E11.5

abnormal vagus ganglion morphology ( J:126634 )

• the dorsal motor nucleus of the vagus is absent

homeostasis/metabolism

abnormal noradrenaline level ( J:126634 )

• similar to Phox2b^tm1Jbr homozygotes, mice exhibit a noradrenergic deficit

cardiovascular system

abnormal cardiovascular system morphology ( J:126634 )

• authors state that mice exhibit a similar to identical phenotype as that observed in Phox2b^tm1Jbr homozygotes