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Fig. 4. Limb abnormalities in Tbx3tm1Pa homozygous mutant
(/) mice. (A-C) Limb morphology of 12.5 dpc embryos. The
hindlimb of Tbx3 mutant mice (B,C) is more severely affected than the
forelimb, although the phenotype is variable between mice and between
contralateral sides of the same mouse. (D) Histology of the forelimb and
hindlimb (inset) of a homozygous mutant embryo showing abnormal development of
the hand plate and severe truncation of the hindlimb. (E,F) Left and right
sides of a homozygous mutant embryo recovered dead near term. (G) Skeletal
preparation of limbs from embryo in E,F. The forelimbs exhibit variable
abnormalities of the posterior elements, including the ulna and digits,
whereas the hindlimb shows severe truncations with a posterior deflection of
the zeugopod and no development of the autopod. (H) Right hindlimb of a late
term homozygous mutant fetus at higher magnification, showing the single digit
attached to the single zeugopod element. (I) Skeletal preparation of the limbs
from a normal age-matched control, at the same magnification as G. AER, apical
ectodermal ridge.