Mouse chimaeras revisited: recollections and reflections.

This very personal and subjective article briefly describes the evolution of techniques used for obtaining mouse chimaeras from various sources (embryos, EC, ES and EG cells), summarizes studies on inter-specific chimaeras, mentions some of other applications ('rescuing' chimaeras), presents the contribution of Ralph Brinster to this area and tries to estimate whether the expectations I expressed in 1961 as to the usefulness of making and studying chimaeras turned out to be correct. Tribute is paid mainly to those, who as the first, contributed to various aspects of these studies.