Phenotypes associated with this allele

• Allele Symbol: Dbx1^tm1Tmj
• Allele Name: targeted mutation 1, Thomas M Jessell
• Allele ID: MGI:2182329
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Dbx1^tm1Tmj/Dbx1^tm1Tmj	involves: 129P2/OlaHsd * C57BL/6	MGI:4837352
hm2	Dbx1^tm1Tmj/Dbx1^tm1Tmj	involves: 129P2/OlaHsd * C57BL/6J	MGI:3694630
cn3	Dbx1^tm2Jcor/Dbx1^tm1Tmj Tg(Nkx2-1-cre)2Sand/0	involves: 129P2/OlaHsd * 129S1/Sv * 129X1/SvJ * C57BL/6	MGI:5697928

Genotype
MGI:4837352

hm1

• Allelic Composition: Dbx1^tm1Tmj/Dbx1^tm1Tmj
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6

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

mortality/aging

neonatal lethality, complete penetrance ( J:165285 )

nervous system

abnormal medulla oblongata morphology ( J:165285 )

• the pre-Botzinger complex exhibit abnormal differentiation compared to in wild-type mice

• mice exhibit impaired pre-Botzinger complex commissural connectivity detected by biocytin staining compared with wild-type mice

• mice exhibit a reduction in glutamatergic interneurons in the pre-Botzinger complex compared with wild-type mice

abnormal pre-Botzinger complex morphology ( J:165285 )

• mice exhibit impaired pre-Botzinger complex commissural connectivity detected by biocytin staining compared with wild-type mice

• mice exhibit a reduction in glutamatergic interneurons in the pre-Botzinger complex compared with wild-type mice

abnormal pre-Botzinger complex physiology ( J:165285 )

• at E15.5, mice fail to exhibit fetal breathing (measured by electrophysiological recordings and calcium imaging of the pre-Botzinger complex) unlike wild-type mice

respiratory system

respiratory failure ( J:165285 )

homeostasis/metabolism

cyanosis ( J:165285 )

Genotype
MGI:3694630

hm2

• Allelic Composition: Dbx1^tm1Tmj/Dbx1^tm1Tmj
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6J

mortality/aging

neonatal lethality, complete penetrance ( J:70191 )

• homozygotes born in expected numbers but die at birth

nervous system

abnormal GABAergic neuron morphology ( J:70191 )

• increased numbers of lateral GABA expressing neurons

abnormal ventral interneuron 0 morphology ( J:70191 , J:89813 )

• V0v interneurons transform into a form somewhat like V1 interneurons (J:70191)

• axons project ipsilaterally but fail to project to the floor plate (J:70191)

• V0d interneurons transform into a form somewhat like dl6 interneurons (J:89813)

abnormal somatic nervous system physiology ( J:89813 )

• alternate right left pattern of motor activity of spinal nerves is inconsistent

• variability in the onset of contralateral step cycles disrupts the strict alternation of motor activity in L2 and L5 motor roots

• flexor-extensor coordination preserved however

Genotype
MGI:5697928

cn3

• Allelic Composition: Dbx1^tm2Jcor/Dbx1^tm1Tmj; Tg(Nkx2-1-cre)2Sand/0
• Genetic Background: involves: 129P2/OlaHsd * 129S1/Sv * 129X1/SvJ * C57BL/6

nervous system

abnormal hypothalamus secretion ( J:221571 )

♀ • attenuated response to predator (rat) odor is observed in females ( as measured by corticosterone levels in the lateral hypothalamus area) as compared to control females

♀ • males (either control or mutant) do not exhibit a response

abnormal action potential ( J:221571 )

• slices from the lateral hypothalamic area (LH) exhibit 85% lower spike density in low glucose

• slices from the lateral hypothalamic area (LH) exhibit 50% lower average spike frequency in high glucose

• however, glucose tolerance is not affected

behavior/neurological

abnormal response to novel odor ( J:221571 )

♀ • females exhibit a similar response following presentation with either rat or benign odor in contrast to controls

♀ • females exhibit fewer and shorter escape behaviors as compared to controls following presentation with rat odor

decreased food intake ( J:221571 )

♀ • females eat less than controls on a restricted diet

decreased compensatory feeding amount ( J:221571 )

♀ • decrease in amount of food consumed following a 12 hour fast is observed in females, but not males

♀ • however, daily food consumption is similar to controls

increased locomotor activity ( J:221571 )

♂ • activity, as determined by horizontal line crossings, is increased in males, but not in females

growth/size/body

decreased body weight ( J:221571 )

• decreased body weight in males, but not females, is observed after weaning

• females exhibit a decrease in body weight under restricted or high fat diets

adipose tissue

decreased percent body fat/body weight ( J:221571 )

♂ • males exhibit decrease in body fat composition after 7 weeks on high fat diet