Distribution of Antigens in the Developing Newt Embryo

Abstract

ABSTRACT Evidence is presented that a synthesis of antigenic material occurs in Triturus alpestris between the blastula and gastrula stage, before neurulation, and between neurulation and the formation of the tail-bud. During early morphogenesis and well before organogenesis the tissues exhibit a lack of antigenic uniformity. The behaviour of six antigenic fractions found in the gastrula have been studied both in their ontogeny and distribution up to the stage of the neurula. Three of these are to be found only after gastrulation. Ectoderm and archenteron roof contain fractions specific to themselves as well as containing some antigens in common. The ectoderm and neural plate of the neurula have some specificity relative to each other. An antigenic fraction specific to a given tissue type may be detected at a stage earlier than that at which this tissue first appears. Two antigenic fractions later characteristic of distinct tissues may coexist in their common precursor. A possible case of in vitro antigenic transformation is described. Antisera exhibit an irregularly cytotoxic effect when used in culture media. Partially absorbed antisera tend to cause abnormalities rather than death of whole embryos. There are indications that a certain degree of specificity in action of absorbed antisera occurs when used in culture media. Such specificity is more definite in the case of isolates of ectoderm and archenteron roof. A difference is found between the susceptibilities of blastulae and gastrulae to antisera which cannot be attributed to their difference in antigenic constitution but must depend on a change in the location of certain antigens or a change in permeability.