Phenotypes associated with this allele

• Allele Symbol: Hhex^tm1Rbe
• Allele Name: targeted mutation 1, Rosa Beddington
• Allele ID: MGI:2177762
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Hhex^tm1Rbe/Hhex^tm1Rbe	B6.129P2-Hhex^tm1Rbe	MGI:3525565
hm2	Hhex^tm1Rbe/Hhex^tm1Rbe	involves: 129P2/OlaHsd * C57BL/6	MGI:3707078

Genotype
MGI:3525565

hm1

• Allelic Composition: Hhex^tm1Rbe/Hhex^tm1Rbe
• Genetic Background: B6.129P2-Hhex^tm1Rbe

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

endocrine/exocrine glands

abnormal thyroid gland development ( J:95017 )

• at E10 morphogenesis of the thyroid bud is severely impaired and the number of thyroid cell precursors is reduced

Genotype
MGI:3707078

hm2

• Allelic Composition: Hhex^tm1Rbe/Hhex^tm1Rbe
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6

mortality/aging

lethality throughout fetal growth and development, complete penetrance ( J:62027 )

• homozygotes begin to die around E11.5, and none are seen by E15.5

embryonic lethality during organogenesis, incomplete penetrance ( J:62027 )

• homozygotes begin to die around E11.5, and by E15.5, no homozygotes are present

growth/size/body

embryonic growth retardation ( J:62027 )

• mutants are often retarded

nervous system

absent Rathke's pouch ( J:62027 )

• class I mutants (about 30%) show a complete lack of Rathke's pouch

abnormal forebrain development ( J:62027 )

• the prospective forebrain ectoderm is correctly induced and patterned at E7.5, but subsequently fails to develop, as indicated by maker analysis

• mutants can be classified into 3 groups (I-III), with class I mutants (about 30%) showing complete absence of the forebrain, class II and III mutants (60%) showing a reduced forebrain, and 10% exhibiting a normal forebrain

abnormal telencephalon development ( J:62027 )

• class I mutants (about 30%) show a complete lack of telencephalic vesicles

• class III mutants (about 30%) have one small telencephalic vesicle

absent embryonic telencephalon ( J:62027 )

• class I mutants (about 30%) show a complete lack of telencephalic vesicles

small embryonic telencephalon ( J:62027 )

• class II mutants (about 30%) show smaller telencephalic vesicles

decreased forebrain size ( J:62027 )

• embryos exhibit a reduction in forebrain tissue at E8.5 that becomes more pronounced with age; defects are restricted to the rostral forebrain and have a caudal limit at the zona limitans intrathalamica, the boundary between dorsal and ventral thalamus

• class II and III mutants (60%) show a reduced forebrain

absent forebrain ( J:62027 )

• class I mutants (about 30%) show complete absence of the forebrain

abnormal medial ganglionic eminence morphology ( J:62027 )

• class II mutants (about 30%) have no dorsal midline or medial ganglionic eminence

embryo

abnormal first pharyngeal arch morphology ( J:62027 )

• class I mutants (about 30%) exhibit a first branchial arch that is fused in the midline and has no pharyngeal endoderm

• class II mutants (about 30%) do not exhibit branchial arch defeccts

fused first pharyngeal arch ( J:62027 )

• class I mutants (about 30%) exhibit a first branchial arch that is fused in the midline

rostral body truncation ( J:62027 )

• varying degrees of anterior truncation such that at E9.5 and E10.5, about 90% of embryos show some anterior truncation

embryonic growth retardation ( J:62027 )

• mutants are often retarded

abnormal anterior definitive endoderm morphology ( J:62027 )

• the development of rostral definitive endoderm is disturbed

taste/olfaction

abnormal nasal placode morphology ( J:62027 )

• class II mutants (about 30%) have one olfactory placode

absent nasal placodes ( J:62027 )

• class I mutants (about 30%) show a complete lack of olfactory placodes

vision/eye

abnormal optic stalk morphology ( J:62027 )

• class II mutants (about 30%) have eyes that are separated by only a short optic stalk

abnormal optic vesicle formation ( J:62027 )

• class II mutants (about 30%) exhibit smaller optic vesicles

anophthalmia ( J:62027 )

• class I mutants (about 30%) show a complete lack of eyes

cardiovascular system

abnormal pericardial cavity morphology ( J:62027 )

• often exhibit large pericardial cavities

endocrine/exocrine glands

absent Rathke's pouch ( J:62027 )

• class I mutants (about 30%) show a complete lack of Rathke's pouch

abnormal thyroid gland morphology ( J:62027 )

• thyroid dysplasia

abnormal thyroid gland development ( J:62027 )

• the thyroid primordium is either absent or hypoplastic at E8.5-9.5

• development of the thyroid is arrested at the thyroid bud stage at E9.5

liver/biliary system

abnormal hepatoblast migration ( J:62027 )

• migration of hepatocytes into the septum transversum fails to occur

abnormal hepatic diverticulum morphology ( J:62027 )

• liver diverticulum is formed but is thinner than normal

absent liver ( J:62027 )

• absence of liver at E10.5-E13.5

craniofacial

abnormal nasal placode morphology ( J:62027 )

• class II mutants (about 30%) have one olfactory placode

absent nasal placodes ( J:62027 )

• class I mutants (about 30%) show a complete lack of olfactory placodes

abnormal first pharyngeal arch morphology ( J:62027 )

• class I mutants (about 30%) exhibit a first branchial arch that is fused in the midline and has no pharyngeal endoderm

• class II mutants (about 30%) do not exhibit branchial arch defeccts

fused first pharyngeal arch ( J:62027 )

• class I mutants (about 30%) exhibit a first branchial arch that is fused in the midline

respiratory system

abnormal nasal placode morphology ( J:62027 )

• class II mutants (about 30%) have one olfactory placode

absent nasal placodes ( J:62027 )

• class I mutants (about 30%) show a complete lack of olfactory placodes

cellular

abnormal hepatoblast migration ( J:62027 )

• migration of hepatocytes into the septum transversum fails to occur