Neural tube defects in curly-tail mice. I. Incidence, expression and similarity to the human condition.

The incidence of neurovertebral defects in mutant mice of the curly-tail strain was investigated and found to be similar to that observed in the same mice twenty-five years ago. The results of breeding experiments support the hypothesis of Grüneberg that the defects in these mice are probably caused by a recessive gene, the expression of which is markedly affected by the genetic background. Selection against the curly-tail phenotype for six generations did not affect the incidence of abnormalities. A marked excess of females was found among exencephalic mice, as among humans with neural tube defects. Similarly, polyhydramnios, hydrocephaly, high levels of amniotic fluid alphafoetoprotein and distinctive, rapidly adhering cells in the amniotic fluid also occurred in these mice, as in humans. The curly-tail mice thus provide a useful model for the investigation of neural tube defects in man.