Phenotypes associated with this allele

• Allele Symbol: Lefty1^tm1Sla
• Allele Name: targeted mutation 1, Siew-Lan Ang
• Allele ID: MGI:2449694
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Lefty1^tm1Sla/Lefty1^tm1Sla	involves: 129/Sv * CD-1	MGI:3775816
cx2	Cer1^tm1Bhr/Cer1^tm1Bhr Lefty1^tm1Sla/Lefty1^tm1Sla Nodal^tm1Rob/Nodal^+	involves: 129S/SvEv * 129S7/SvEvBrd * CD-1	MGI:3775810
cx3	Cer1^tm1Bhr/Cer1^tm1Bhr Lefty1^tm1Sla/Lefty1^tm1Sla	involves: 129S7/SvEvBrd * CD-1	MGI:3775806

Genotype
MGI:3775816

hm1

• Allelic Composition: Lefty1^tm1Sla/Lefty1^tm1Sla
• Genetic Background: involves: 129/Sv * CD-1

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

growth/size/body

left pulmonary isomerism ( J:81339 )

• about one-third of homozygous mutants display left pulmonary isomerism at 17.5 dpc and at neonatal stages

respiratory system

left pulmonary isomerism ( J:81339 )

• about one-third of homozygous mutants display left pulmonary isomerism at 17.5 dpc and at neonatal stages

Genotype
MGI:3775810

cx2

• Allelic Composition: Cer1^tm1Bhr/Cer1^tm1Bhr; Lefty1^tm1Sla/Lefty1^tm1Sla; Nodal^tm1Rob/Nodal⁺
• Genetic Background: involves: 129S/SvEv * 129S7/SvEvBrd * CD-1

embryo

abnormal embryo development ( J:81339 )

• all triple mutant embryos at 7.5 dpc show morphological defects similar to or less severe than Cer1 Lefty1 double mutants

abnormal developmental patterning ( J:81339 )

abnormal embryonic tissue morphology ( J:81339 )

abnormal embryonic-extraembryonic boundary morphology ( J:81339 )

Genotype
MGI:3775806

cx3

• Allelic Composition: Cer1^tm1Bhr/Cer1^tm1Bhr; Lefty1^tm1Sla/Lefty1^tm1Sla
• Genetic Background: involves: 129S7/SvEvBrd * CD-1

mortality/aging

embryonic lethality during organogenesis, incomplete penetrance ( J:81339 )

• 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

abnormal embryonic epiblast morphology ( J:81339 )

• 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

abnormal lateral plate mesoderm morphology ( J:81339 )

• class I and II mutants have severely reduced amounts of lateral mesoderm cells

abnormal paraxial mesoderm morphology ( J:81339 )

• in class I and II mutants, paraxial mesoderm precursors are absent or misspecified

abnormal primitive streak morphology ( J:81339 )

• 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

abnormal primitive streak formation ( J:81339 )

• 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

absent somites ( J:81339 )

• somites are not observed in some class III mutants at 8.5 and 9.5 dpc

embryonic-extraembryonic boundary constriction ( J:81339 )

• 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