Some Physiological Aspects of Organogenesis in the Insect Embryo

Abstract

AbstractIn the embryo, as in the postembryonic insect, morphological development is accompanied by an increase or change in enzyme activity. The appearance of certain enzymatically active proteins in a particular tissue or organ may indicate when that tissue or organ has become functional. The time and place of appearance of several types of esterase has been determined in the tissues and organs of the developing embryo of the large milkweed bug,Oncopeltus fasciatus(Dall.). The appearance of acetylcholinesterase in the neuropile of the nervous system reflects the morphological development of this system; it may also determine the onset of functional activity. Similarly, the appearance of non-specific esterase in many tissues and organs at a definite time during their morphological development suggests a relationship between their functional differentiation and the appearance of the enzyme. Evidence for such a relationship will remain circumstantial until the physiological significance of these esterases is understood.