• about 15% show mid-gestation lethality

• about 15% show severe gastrulation defects

• low frequency of mandible hypoplasia

• delay in maturation of the testes (J:57262)

• delay in maturation of the testes (J:57262)

• partial sterility of females (J:57262)

• low frequency of mandible hypoplasia

• low frequency of mild cyclopia

• embryonic lethality although time not specified

• over 60% show gastrulation defects

• 6 of 8 newborns show truncation of rostral head structures

• 4 of 13 embryos that developed beyond gastrulation have a reduced forebrain

• 6 of 8 newborns display cyclopia

• 100% penetrance of vertebral transformation of the 21st vertebra into the 14th thoracic vertebra

• 12 of 13 show effects associated with left-right asymmetry such as right pulmonary isomerism and transposition of great arteries

• die before or during gastrulation and are resorbed by E8.5

• cell death is seen in the epiblast of some embryos

• do not form mesoderm

• exhibit a constriction at the embryonic and extraembryonic junction and the separation of the visceral endoderm and the epiblast

• embryos are growth arrested at the early egg cylinder stage

• cell death is seen in the epiblast of some embryos

• die before or during gastrulation; by E9.5, embryos are partially or completely degenerated

• gastrulation is initiated but severely impaired subsequently

• severe gastrulation defects ranging from the lack of discernible embryonic axes to the formation or relatively normal axial and paraxial structures

• primitive streak elongation is disrupted

• exhibit defects in anterior patterning as indicated by marker expression

• the few embryos that are able to undergo relatively normal gastrulation, exhibit abnormal anterior neural development

• almost all embryos with gastrulation defects do not form the head-fold structure

• formation of the embryonic mesoderm is severely impaired

• often show a constriction at the embryonic and extraembryonic junction, leading to the protrusion of embryos outside the yolk sac at E8.5

• absent in most mutants

• absent in most mutants

• almost all embryos with gastrulation defects do not form a primitive heart

• die late in development or shortly after birth

• 6 of 16 exhibit transformation of the 21st vertebra into the 14th thoracic vertebra

• 12 of 13 show effects associated with left-right asymmetry such as right pulmonary isomerism and transposition of great arteries

• the embryonic tissues grow outside of the yolk sac

• exhibit constrictions at the junction between the extraembryonic and embryonic regions at E7.5

• development is arrested at the gastrulation stage (E8.5)