Phenotypes Associated with This Genotype

Genotype
MGI:2176494

• Allelic Composition: Htt^tm1Mem/Htt^tm1Mem
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * C57BL/6 * CD-1

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

mortality/aging

embryonic lethality between somite formation and embryo turning, complete penetrance ( J:27183 )

• by E8.5, all homozygous embryos are being resorbed, while only resorption sites are found at E9.5

embryo

abnormal developmental patterning ( J:27183 )

abnormal ectoderm development ( J:27183 )

• embryonic ectoderm is symmetrical and featureless, without evidence of head folds

• ectoderm is thicker than normal, and is disorganized rather than columnar especially distally

increased ectoderm apoptosis ( J:27183 )

• ~10% of cells are pyknotic compared to <1% in normal embryos

decreased embryo size ( J:27183 )

• at E7.5, homozygous embryos are ~2/3 of normal size and misshapen; at E7.0, some homozygous embryos are observed to be smaller and thinner than other embryos in the litter

abnormal embryonic tissue morphology ( J:27183 )

• embryonic region appears shrunken at E7.5

absent primitive node ( J:27183 )

• at E7.5, primitive streak at one end of embryos forms, but no node structure is evident

embryonic-extraembryonic boundary constriction ( J:27183 )

• at E7.5, there is prominent constriction between the extraembryonic and embryonic regions of homozygotes

abnormal extraembryonic tissue morphology ( J:27183 )

• at E7.5, extraembryonic region is reduced in size

abnormal extraembryonic endoderm formation ( J:27183 )

• columnar cells of endoderm are not organized into tight sheath as in normal embryos, but form a folded layer extending around shrunken embryonic region

abnormal extraembryonic mesoderm development ( J:27183 )

• mesoderm cells line yolk sac, amnion, and chorion, but do not extend to distal pole

• cells are abnormally rounded and densely, not loosely, packed

growth/size/body

decreased embryo size ( J:27183 )

• at E7.5, homozygous embryos are ~2/3 of normal size and misshapen; at E7.0, some homozygous embryos are observed to be smaller and thinner than other embryos in the litter

cellular

increased ectoderm apoptosis ( J:27183 )

• ~10% of cells are pyknotic compared to <1% in normal embryos

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
NOT	Huntington's disease	DOID:12858	OMIM:143100	J:27183