Fig. 4. External phenotype of the MFCS1 KO mouse. (A,B) The limbs of the MFCS1 KO embryos at E12.5 are extremely reduced. (C,D) In the KO embryos at E14.5, the distal ends of the limbs becomes very thin. (E) A 10-day post-natal MFCS1 KO homozygote appears quite healthy, except for the limb abnormality. (F) The body size of a 3-week-old MFCS1 KO homozygote (right) is comparable to that of wild-type (left). (G-J) Magnified pictures of the forelimbs (G,I) and hindlimbs (H,J) in the MFCS1 KO homozygote. The autopod is not recognizable in the forelimbs. In the hindlimbs, only one digit with a nail is observed (H). On the surface of the ventral side of the digit, pad-like tissue is observed (J).