Phenotypes associated with this allele

• Allele Symbol: Mllt3^tm1.1Thr
• Allele Name: targeted mutation 1.1, Terence H Rabbitts
• Allele ID: MGI:2388982
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Mllt3^tm1.1Thr/Mllt3^tm1.1Thr	involves: 129S/SvEv * C57BL/6	MGI:3043758

Genotype
MGI:3043758

hm1

• Allelic Composition: Mllt3^tm1.1Thr/Mllt3^tm1.1Thr
• Genetic Background: involves: 129S/SvEv * C57BL/6

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

mortality/aging

perinatal lethality, incomplete penetrance ( J:79367 )

• approximately 50% of homozygotes were found dead at birth or within hours thereafter

postnatal lethality, complete penetrance ( J:79367 )

• the remaining 50% died within the first 2 weeks

• no homozygotes survived to weaning; however, no gross malformations or organ abnormalities were observed

growth/size/body

decreased body size ( J:79367 )

• approximately 50% of homozygotes became severely runted prior to death

skeleton

skeleton phenotype ( J:79367 )

N • the number and morphology of all the lumbar and caudal vertebrae, as well as the appendicular skeleton, appeared normal

abnormal sternum morphology ( J:79367 )

• sternums were deformed, consisting mainly of bone rather than of segments of bone separated by cartilage

asymmetric sternocostal joints ( J:79367 )

• the ribs of mutant pups were not attached to the sternum in pairs but rather were staggered randomly

decreased rib number ( J:79367 )

• mutants lacked a pair of floating ribs and the associated vertebra, having a total number of 12 instead of 13 pairs of ribs and vertebrae

• only 1 out of 13 skeletons from mutant pups had a 13th thoracic vertebra, but this carried very small rib anlagen

abnormal thoracic vertebrae morphology ( J:79367 )

• the spinous process normally found on the second thoracic vertebra (T2) was observed on T3 instead

abnormal cervical vertebrae morphology ( J:79367 )

• most homozygotes had a total number of eight cervical vertebrae as opposed to the normal seven

• occasionally, C3 was partially fused to C2, but with a vertebral body of its own

• mutants generally exhibited small protruding rib anlagen on vertebra C8, whereas wild-type mice usually had a pair of cervical ribs on C6

• in the C3-to-C8 region, the cervical spine was markedly compressed, causing an S-shaped deformation of the neck and a forward tilt of the head

abnormal cervical atlas morphology ( J:79367 )

• the atlas (C1) appeared as two vertebrae partially fused, with a single vertebral body extending along both substructures

vertebral transformation ( J:79367 )

• mutant newborns displayed an anterior homeotic transformation of the axial skeleton throughout most of the cervical region and the entire thoracic region

• this vertebral transformation resulted in the shift of C3->C2 through to T13->T12, with C3 possibly resulting from a duplication of the C2 segment

thoracic vertebral transformation ( J:79367 )

cervical vertebral transformation ( J:79367 )

embryo

abnormal developmental patterning ( J:79367 )

• in situ hybridization analysis of E9.5 mutant embryos revealed a posterior shift in the anterior expression limits of Hoxd4, corresponding to approximately one rhombomere, indicating altered embryo patterning

hematopoietic system

hematopoietic system phenotype ( J:79367 )

N • mutant neonates displayed normal hematopoiesis, as shown by histology and flow cytometry