The Embryos Obtained from the Karyoplasts of Starfish Oocytes: Their Development and Sensitivity to Cytostatic Neurotransmitter Antagonists

Karyoplasts obtained from full-grown oocytes of the starfish Aphelasterias japonica have practically no cytoplams and are incapable of maturation. Karyoplasts of oocytes of starfishes Marthasterias glacialis and Acanthaster planci have the cytoplasm (10%–15% of the total karyoplast volume) and are often capable of maturation, fertilization and one or several cleavage divisions. The embryoskaryoplasts completely lose supersensitivity and retain usual sensitivity to cytostatic antagonists of neurotransmitters. The assumption is made that the incapability or limited capability of this embryos for development might be due to a deficiency of certain components of the "prenervous" neurotransmitter systems.