Development of several organs that require inductive epithelial-mesenchymal interactions is impaired in LEF-1-deficient mice.

TLDR

LEF‑1 is a sequence‑specific transcription factor expressed in embryonic tissues such as neural crest derivatives, tooth germs, whisker follicles, and the mesencephalon. LEF‑1‑null mice die after birth and lack teeth, mammary glands, whiskers, hair, and the mesencephalic nucleus of the trigeminal nerve, indicating that LEF‑1 is essential for the development of organs that depend on inductive epithelial‑mesenchymal interactions.

Abstract

Lymphoid enhancer factor 1 (LEF-1) is a sequence-specific DNA-binding protein that is expressed in pre-B and T lymphocytes of adult mice, and in the neural crest, mesencephalon, tooth germs, whisker follicles, and other sites during embryogenesis. We have generated mice carrying a homozygous germ-line mutation in the LEF-1 gene that eliminates its protein expression and causes postnatal lethality. The mutant mice lack teeth, mammary glands, whiskers, and hair but show no obvious defects in lymphoid cell populations at birth. The LEF-1-deficient mice also lack the mesencephalic nucleus of the trigeminal nerve, the only neural crest-derived neuronal populations. Together, the pattern of these defects suggest an essential role for LEF-1 in the formation of several organs and structures that require inductive tissue interactions.