Mice that are heterozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Homozygous null mice have a perinatal lethal phenotype and die within 24 hours of birth. Occasional expression of gene product (mRNA) is detected in poorly organized kidney aggregate tissue of homozygous embryos by in situ hybridization analysis. Expression (mRNA) is not altered in the central nervous systme and mesonephric mesenchyme. Homozygous embryos have small kidneys with morphologically undifferentiated renal mesenchyme. The pituitary glands exhibit abnormal morphology. This mutant mouse strain may be useful in studies of renal development. The Jackson Laboratory 2024, used with permission.