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Phenotypes Associated with This Genotype
Genotype
MGI:3775806
Allelic
Composition
Cer1tm1Bhr/Cer1tm1Bhr
Lefty1tm1Sla/Lefty1tm1Sla
Genetic
Background
involves: 129S7/SvEvBrd * CD-1
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Cer1tm1Bhr mutation (0 available); any Cer1 mutation (11 available)
Lefty1tm1Sla mutation (0 available); any Lefty1 mutation (41 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• by 9.5 dpc, 9.4% of embryos recovered are double nulls instead of expected 25%; surviving embryos are divided into classes I, II and III based on phenotypic characteristics
• Mendelian numbers are detected at 8.5 dpc

embryo
• at 6.5 dpc, abnormalities can be observed, such as an accumulation of visceral endoderm cells at the presumptive anterior pole of the embryo
• abnormal thickening of the proximal anterior epiblast is observed and perisists to 7.5 dpc
• in some class II and III embryos, anterior and/or lateral protrusions ectoderm protrusions contact the opposite side of the ectoderm, leading to pinching of the embryonic region separating it into two or three distinct embryonic axes at 8.5 and 9.5 dpc
• in some double null embryos, accumulation of pyknotic arising from the ectodermal protrusions is observed in the amniotic cavity
• class I and II mutants have severely reduced amounts of lateral mesoderm cells
• in class I and II mutants, paraxial mesoderm precursors are absent or misspecified
• class III double mutants develop multiple primitive streaks at 8.5 and 9.5 dpc; ectopic primitive streak initiation begins later than the endogenous streak
• expansion of the anterior primitive streak and its derivatives is observed in class I and II embryos at 7.5 dpc; anterior definitive endoderm is expanded in class I mutant embryos
• at 7.5 dpc in class II mutants, visceral endoderm cells persist in the anterior embryonic region
• somites are not observed in some class III mutants at 8.5 and 9.5 dpc
• class II and III double null embryos (29% of total) show separation of embryonic and extraembryonic regions by a tight constriction, resulting in physical separation of embryonic and extraembryonic ectoderm


Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
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last database update
01/28/2026
MGI 6.24
The Jackson Laboratory