Inductive tissue interaction in the development of the mouse lens in vitro

Abstract

Inductive tissue interaction involved in lens differentiation in the mouse embryo has been studied using millipore filter culture methods. The entire eye rudiment (nine day embryo) comprising optic vesicle, surrounding mesenchyme and overlying ectoderm differentiated in vitro into lens and retina, essentially as in normal development. Individual tissue components of trypsin-separated lens primordia lost their structural organization when cultured alone, but lens epithelium in combination with mesenchyme was maintained as a vesicle without obvious lens fiber formation. Tissue recombination experiments show that differentiation of lens fibers in the presumptive lens ectoderm as well as in the lens placode depends on the inductive influence of optic cup. This influence can pass through a millipore filter barrier of 25 μ thickness and 0.45 μ porosity. Differentiation of lens fibers in the anterior lens epithelium of later embryos was also dependent on the inductive action of neural retina, suggesting the presence of continued inductive interaction in lens formation. The initial influence of optic vesicle on the presumptive lens ectoderm seems to be critical and of short duration, leading to the formation of a placode which has acquired stabilized lens forming property. Continued realization of this property depends on further inductive action.