Development of Aberrant Crypt Foci Involves a Fission Mechanism as Revealed by Isolation of Aberrant Crypts

Morphological analysis of isolated colonic crypts in rats, postnatally, indicated that the crypts reproduce themselves by a fission mechanism, the division beginning at the crypt base and proceeding upwards until there are two separate crypts. Occasionally, before the separation is complete, a second fission process starts on one or both sides of a bifurcating crypt and a triple‐branched or quadruple‐branched crypt results. Analysis of isolated aberrant crypt foci (ACF) in rats treated with 1,2‐dimethylhydrazine revealed that the development of ACF consisting of multiple crypts is also due to a fission mechanism. Initially, an indentation appears at the base of a single ACF crypt, with subsequent formation of a bifurcation and eventual crypt division.