XB-ART-32801Cell March 1, 1975; 4 (3): 269-74.
Effects of cycloheximide on the "autocatalytic" nature of the maturation promoting factor (MPF) in oocytes of Xenopus laevis.
It is shown that a factor arising during the course of maturation in amphibian oocytes is by itself capable of inducing maturation when injected into recipient oocytes even after a series of 10 transfers. The mechanism of action of this phenomenon is shown to be under translational control. Experiments using cycloheximide suggest that MPF does not need protein synthesis for germinal vesicle breakdown (GVBD), but does require a translational step when serially transferred in order to sustain its renewal ("autocatalytic") capacity. It is further shown that oocytes of Xenopus laevis lend themselves to an in vitro system, since when matured under the action of some steroids (progesterone or hydrocortisone), they are capable of supporting functional maturation with cleavage and development after having received a transplanted blastula nucleus.
PubMed ID: 1122557
Article link: Cell
Genes referenced: cdk1
Article Images: [+] show captions
|Figure 1 . Effects of Protein Synthesis Inhibition on the Serial Transfers of the Maturation Promoting Factor (MPF) Cycloheximide was injected into oocytes 10 min before injection of MPF at a concentration of 10 mg/ml . Injected amounts were constant and approximately 50 nI . The subscript (m) on oocytes indicates maturation of the respective oocyte directly above . Experiments were carried out on two animals . Pipette illustrations are as follows : Shaded pipettes with accompanying arrow represents the uptake of cytoplasmic material. Nonshaded pipettes with accompanying arrow represents the injection of cytoplasmic material into the respective recipient oocyte . Numbers in brackets reflect matured oocytes over the number injected .|
|Figure 2. Cleavage Resulting from the Transplantation of a Blastula Nucleus into In Vitro Steroid-Matured Oocytes of Xenopus laevis (a) Development to morula stage. Magnification 30x (b) A 7p-stained section of morula stage depicting true cleavage. Magnification 90x|