Phenotypes associated with this allele

• Allele Symbol: Ttc21b^aln
• Allele Name: alien
• Allele ID: MGI:2152544
• Summary: 9 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ttc21b^aln/Ttc21b^aln	B6.A(FVB)-Ttc21b^aln	MGI:6402431
hm2	Ttc21b^aln/Ttc21b^aln	involves: A/J	MGI:2181876
hm3	Ttc21b^aln/Ttc21b^aln	involves: A/J * FVB	MGI:6402429
cn4	Ttc21b^tm2c(KOMP)Wtsi/Ttc21b^aln Gt(ROSA)26Sor^tm1(cre/ERT)Nat/Gt(ROSA)26Sor^+	involves: 129S1/Sv * 129X1/SvJ * A/J * C57BL/6N	MGI:5587035
cx5	Gpr63^em2Rstot/Gpr63^em2Rstot Ttc21b^aln/Ttc21b^aln	involves: A/J * C57BL/6 * FVB	MGI:6392828
cx6	Gpr63^em1Rstot/Gpr63^em2Rstot Ttc21b^aln/Ttc21b^aln	involves: A/J * C57BL/6 * FVB	MGI:6392831
cx7	Gpr63^em1Rstot/Gpr63^em1Rstot Ttc21b^aln/Ttc21b^aln	involves: A/J * FVB	MGI:6392838
cx8	Gpr63^em1Rstot/Gpr63^rs13477613-T Ttc21b^aln/Ttc21b^+	involves: A/J * FVB	MGI:6392836
cx9	Gpr63^rs13477613-T/Gpr63^rs13477613-T Ttc21b^aln/Ttc21b^aln	involves: A/J * FVB	MGI:6392840

Genotype
MGI:6402431

hm1

• Allelic Composition: Ttc21b^aln/Ttc21b^aln
• Genetic Background: B6.A(FVB)-Ttc21b^aln

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

growth/size/body

microcephaly ( J:282171 )

• 30% reduction in forebrain area compared to wildtype; less severe than this allele in FVB background

• olfactory bulb absent

nervous system

forebrain hypoplasia ( J:282171 )

• 30% reduction in forebrain area compared to wildtype; less severe than this allele in FVB background

absent olfactory bulb ( J:282171 )

Genotype
MGI:2181876

hm2

• Allelic Composition: Ttc21b^aln/Ttc21b^aln
• Genetic Background: involves: A/J

craniofacial

abnormal craniofacial morphology ( J:75360 )

• mice are described as having craniofacial abnormalities

limbs/digits/tail

polydactyly ( J:75360 )

• preaxial polydactyly was reported

abnormal limb bone morphology ( J:75360 )

• severe defects in the length and shape of long bones

skeleton

abnormal limb bone morphology ( J:75360 )

• severe defects in the length and shape of long bones

rib fusion ( J:75360 )

• rib fusions were observed

truncated ribs ( J:75360 )

• rib truncations were observed

abnormal vertebrae morphology ( J:75360 )

• described as misaligned

nervous system

abnormal neural tube morphology ( J:75360 )

• mice are described as having neural tube defects

abnormal brain morphology ( J:75360 )

• described as disorganized brain architecture

absent olfactory bulb ( J:75360 )

embryo

abnormal neural tube morphology ( J:75360 )

• mice are described as having neural tube defects

renal/urinary system

polycystic kidney ( J:213263 )

• cystic dilations of glomeruli and surrounding tubules at E16.5 and P0

• renal tubular dilations originate in proximal tubules and ascending loops of Henle

growth/size/body

polycystic kidney ( J:213263 )

• cystic dilations of glomeruli and surrounding tubules at E16.5 and P0

• renal tubular dilations originate in proximal tubules and ascending loops of Henle

Genotype
MGI:6402429

hm3

• Allelic Composition: Ttc21b^aln/Ttc21b^aln
• Genetic Background: involves: A/J * FVB

growth/size/body

microcephaly ( J:282171 )

• 60% reduction in forebrain area compared to wildtype; more severe than this allele in B6 background

• olfactory bulb absent

nervous system

forebrain hypoplasia ( J:282171 )

• 60% reduction in forebrain area compared to wildtype; more severe than this allele in B6 background

absent olfactory bulb ( J:282171 )

Genotype
MGI:5587035

cn4

• Allelic Composition: Ttc21b^{tm2c(KOMP)Wtsi}/Ttc21b^aln; Gt(ROSA)26Sor^{tm1(cre/ERT)Nat}/Gt(ROSA)26Sor⁺
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * A/J * C57BL/6N
• Cell Lines: EPD0041_2_E09

renal/urinary system

increased kidney cell proliferation ( J:213263 )

• an increase in cell proliferation is seen in kidney tubules of 6-week old offspring from pregnant females injected with tamoxifen at E17.5

• from P15 to P20, an increase in cell proliferation in the renal medulla is seen the offspring of females injected with tamoxifen at E17.5

abnormal kidney morphology ( J:213263 )

• levels of cAMP are higher in cystic kidneys of the offspring of E17.5 pregnant females injected with tamoxifen

decreased kidney epithelial cell primary cilium length ( J:213263 )

• kidney primary cilia are stunted and show accumulation of IFT88 protein in bulb-like structures at the distal tips in the offspring of E17.5 pregnant females injected with tamoxifen

• from P15 to P20, an increase in cell proliferation in the renal medulla is seen the offspring of females injected with tamoxifen at E17.5

polycystic kidney ( J:213263 )

• when E17.5 pregnant females are injected intraperitoneally with tamoxifen to induce ubiquitous deletion of Ttc21b, the 6 week old offspring develop cystic kidney disease

• cysts seen in the offspring of E17.5 pregnant females injected with tamoxifen originate from proximal tubules, loops of Henle, and collecting ducts

• 5 week old mice injected intraperitoneally with tamoxifen do not develop kidney cysts after 3 months

• kidneys from offspring of E17.5 pregnant females grown in culture in the presence of 8-bromo-cAMP exhibit increased cystogenic potential and treatment of these cultures with Gant61, a small molecule GLI antagonist, or Sant2, a small molecule SMO antagonist, inhibitors reduces cystogenic potential

increased kidney weight ( J:213263 )

• elevation in ratio of percent kidney weight to body weight is seen in the offspring of E17.5 pregnant females injected with tamoxifen

abnormal loop of Henle morphology ( J:213263 )

• dilations of loops of Henle in the kidney cortex are seen by P15 in the offspring of pregnant females injected with tamoxifen at E17.5

dilated proximal convoluted tubule ( J:213263 )

• dilations of proximal tubules in the kidney cortex are seen by P15 in the offspring of pregnant females injected with tamoxifen at E17.5

homeostasis/metabolism

increased blood urea nitrogen level ( J:213263 )

• increase in BUN levels is seen in the offspring of E17.5 pregnant females injected with tamoxifen

cellular

decreased kidney epithelial cell primary cilium length ( J:213263 )

• kidney primary cilia are stunted and show accumulation of IFT88 protein in bulb-like structures at the distal tips in the offspring of E17.5 pregnant females injected with tamoxifen

• from P15 to P20, an increase in cell proliferation in the renal medulla is seen the offspring of females injected with tamoxifen at E17.5

increased kidney cell proliferation ( J:213263 )

• an increase in cell proliferation is seen in kidney tubules of 6-week old offspring from pregnant females injected with tamoxifen at E17.5

• from P15 to P20, an increase in cell proliferation in the renal medulla is seen the offspring of females injected with tamoxifen at E17.5

growth/size/body

polycystic kidney ( J:213263 )

• when E17.5 pregnant females are injected intraperitoneally with tamoxifen to induce ubiquitous deletion of Ttc21b, the 6 week old offspring develop cystic kidney disease

• cysts seen in the offspring of E17.5 pregnant females injected with tamoxifen originate from proximal tubules, loops of Henle, and collecting ducts

• 5 week old mice injected intraperitoneally with tamoxifen do not develop kidney cysts after 3 months

• kidneys from offspring of E17.5 pregnant females grown in culture in the presence of 8-bromo-cAMP exhibit increased cystogenic potential and treatment of these cultures with Gant61, a small molecule GLI antagonist, or Sant2, a small molecule SMO antagonist, inhibitors reduces cystogenic potential

increased kidney weight ( J:213263 )

• elevation in ratio of percent kidney weight to body weight is seen in the offspring of E17.5 pregnant females injected with tamoxifen

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
cystic kidney disease		DOID:2975		J:213263

Genotype
MGI:6392828

cx5

• Allelic Composition: Gpr63^em2Rstot/Gpr63^em2Rstot; Ttc21b^aln/Ttc21b^aln
• Genetic Background: involves: A/J * C57BL/6 * FVB

embryo

spina bifida cystica ( J:282171 )

• in 5 of 9 E10.5-14.5 embryos

spina bifida occulta ( J:282171 )

limbs/digits/tail

polydactyly ( J:282171 )

• in 1 of 9 E10.5-14.5 embryos and in 2 surviving (of 8) E17.5-18.5 embryos

mortality/aging

lethality throughout fetal growth and development, incomplete penetrance ( J:282171 )

• in 6 of 8 E17.5-18.5 embryos

nervous system

spina bifida cystica ( J:282171 )

• in 5 of 9 E10.5-14.5 embryos

spina bifida occulta ( J:282171 )

exencephaly ( J:282171 )

• in 2 surviving (of 8) E17.5-18.5 embryos and 8 of 9 E10.5-14.5 embryos

skeleton

spina bifida occulta ( J:282171 )

growth/size/body

spina bifida cystica ( J:282171 )

• in 5 of 9 E10.5-14.5 embryos

Genotype
MGI:6392831

cx6

• Allelic Composition: Gpr63^em1Rstot/Gpr63^em2Rstot; Ttc21b^aln/Ttc21b^aln
• Genetic Background: involves: A/J * C57BL/6 * FVB

growth/size/body

microcephaly ( J:282171 )

• 25% reduction in forebrain area compared to Ttc21b^aln/ Ttc21b^aln;Gpr63^em1Rstot/Gpr63^rs13477613-T mice

nervous system

forebrain hypoplasia ( J:282171 )

• 25% reduction in forebrain area compared to Ttc21b^aln/ Ttc21b^aln;Gpr63^em1Rstot/Gpr63^rs13477613-T mice

Genotype
MGI:6392838

cx7

• Allelic Composition: Gpr63^em1Rstot/Gpr63^em1Rstot; Ttc21b^aln/Ttc21b^aln
• Genetic Background: involves: A/J * FVB

nervous system

exencephaly ( J:282171 )

Genotype
MGI:6392836

cx8

• Allelic Composition: Gpr63^em1Rstot/Gpr63^rs13477613-T; Ttc21b^aln/Ttc21b⁺
• Genetic Background: involves: A/J * FVB

nervous system

exencephaly ( J:282171 )

Genotype
MGI:6392840

cx9

• Allelic Composition: Gpr63^rs13477613-T/Gpr63^rs13477613-T; Ttc21b^aln/Ttc21b^aln
• Genetic Background: involves: A/J * FVB

nervous system

exencephaly ( J:282171 )