Phenotypes Associated with This Genotype

Genotype
MGI:2176812

• Allelic Composition: Fgf8^tm1.2Mrt/Fgf8^tm1.2Mrt
• Genetic Background: involves: 129P2/OlaHsd

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:45909 )

• all homozygotes are resorbed by E10.5

• by E9.5 embryos begin to die likely because the heart does not form

embryo

abnormal ectoderm development ( J:56519 )

• ectoderm on the anterior side of the embryo appears undifferentiated and fails to form a neural tube

abnormal mesoderm development ( J:45909 , J:56519 )

• all embryonic mesoderm-derived structures appear to be absent including the heart (J:45909)

• at E8.5 embryos lack all mesodermally-derived tissues including the heart and somites; little mesoderm is detected anterior to the primitive streak (J:56519)

decreased embryo size ( J:45909 )

• embryos are significantly smaller than wild-type or heterozygous littermates at E8.5 and E9.5

abnormal embryonic epiblast morphology ( J:56519 )

• after cells undergo epithelial-mesenchymal transition, at E7.5, majority of nascent mesodermal cells fail to migrate away from the primitive streak, resulting in deformation of the epiblast and inward collapse of the posterior side of the embryo

absent primitive node ( J:56519 )

• node does not form in mutants

absent somites ( J:56519 )

• somites do not develop

abnormal primitive streak elongation ( J:56519 )

• at E7.5 in mutant embryos the streak never extends to the distal tip of the embryo

abnormal allantois morphology ( J:56519 )

• allantois is displaced anteriorly

abnormal amnion morphology ( J:56519 )

abnormal chorion morphology ( J:56519 )

• a chorion can be identified but is often tortuous

growth/size/body

decreased embryo size ( J:45909 )

• embryos are significantly smaller than wild-type or heterozygous littermates at E8.5 and E9.5

cardiovascular system

absent heart ( J:45909 , J:56519 )

• the heart does not form (J:45909)