Figure 4.

Anephrogenic Phenotype of SALL1^−/− Fetus and Its Compensation by Blastocyst Complementation

(A) Anephrogenic phenotype of a SALL1^−/− cloned fetus at mid-gestation (day 43). WT, kidney of age-matched control.

(B) Histological features of the vestigial kidney tissues. Upper panels indicate phenotypic variation in SALL1^−/− fetuses. Immunostaining of the SALL1^−/− vestigial kidney (lower right) detected no SALL1 expression. Lower left: SALL1-positive WT tissue. Scale bars, 200 μm.

(C) Normally developed kidneys of a chimeric fetus (day 43, left) obtained by blastocyst complementation. Note that the bladder was torn off from the ureter at the time of excising. huKO-tg, normally formed kidneys of a control fetus expressing huKO fluorescence. SALL1-KO, deficient renal development of a SALL1^−/− fetus. Scale bars, 5 mm.

(D) Histological features of the kidney tissues (upper panels) from a chimeric fetus produced by blastocyst complementation. Fluorescence expression shown in the upper right panel indicates that renal development in the chimeric fetus is entirely compensated by exogenous cells by blastocyst complementation. Lower panels: renal tissues of a control WT fetus. Scale bars, 100 μm.

See also Figure S4.