Phenotypes associated with this allele

• Allele Symbol: Ttbk2^bby
• Allele Name: bartleby
• Allele ID: MGI:5496675
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Ttbk2^bby/Ttbk2^bby	involves: C57BL/6J * FVB	MGI:5496688
ht2	Ttbk2^bby/Ttbk2^tm1Dral	involves: C57BL/6	MGI:6305409
ht3	Ttbk2^bby/Ttbk2^tm1a(EUCOMM)Hmgu	involves: C57BL/6 * C57BL/6N	MGI:6305411

Genotype
MGI:5496688

hm1

• Allelic Composition: Ttbk2^bby/Ttbk2^bby
• Genetic Background: involves: C57BL/6J * FVB

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:197579 )

• mice die mid-gestation (E10.5)

embryo

abnormal embryonic tissue morphology ( J:197579 )

• twisted body axis

abnormal neural tube morphology ( J:197579 )

• despite the presence of basal bodies, the neural tube lacks cilia

cellular

abnormal cilium morphology ( J:197579 )

• mouse embryonic fibroblasts exhibit impaired ciliogenesis and lack cilia compared with wild-type cells

• however, the defect is rescued by wild-type protein

cardiovascular system

abnormal direction of heart looping ( J:197579 )

• randomized laterality

limbs/digits/tail

abnormal limb development ( J:197579 )

nervous system

abnormal neural tube morphology ( J:197579 )

• despite the presence of basal bodies, the neural tube lacks cilia

holoprosencephaly ( J:197579 )

Genotype
MGI:6305409

ht2

• Allelic Composition: Ttbk2^bby/Ttbk2^tm1Dral
• Genetic Background: involves: C57BL/6

cellular

absent embryonic cilia ( J:269515 )

• embryos do not form any cilia

embryo

absent embryonic cilia ( J:269515 )

• embryos do not form any cilia

Genotype
MGI:6305411

ht3

• Allelic Composition: Ttbk2^bby/Ttbk2^{tm1a(EUCOMM)Hmgu}
• Genetic Background: involves: C57BL/6 * C57BL/6N
• Cell Lines: HEPD0767_5_E08

mortality/aging

perinatal lethality, complete penetrance ( J:269515 )

• embryos and neonates are recovered at nearly Mendelian frequencies up to birth but die by P1

cellular

abnormal cilium morphology ( J:269515 )

• mouse embryonic fibroblasts (MEFs) show fewer cells that are ciliated compared to controls MEFs

• mean cilia length is reduced in MEFs

• treatment of MEFs with nocodazole results in a modest decrease in the percentage of ciliated cells compared to wild-type MEFs that show a slight decrease, indicating that cilium stability is somewhat compromised

• however, overall structure of cilia in neural tube sections from E10.5 embryos is normal

limbs/digits/tail

polydactyly ( J:269515 )

• fully penetrant polydactyly on all 4 limbs at E15.5

nervous system

abnormal nervous system development ( J:269515 )

• E10.5 embryos exhibit only mild defects in neural patterning, with normal distribution of motor neurons but a small number of motor neurons at the ventral midline and an increase in the number of NKX2.2+ and OLIG2+ cells