PubMed Health⌕ Search

Biomedical subjects

W J Wasserman

Publications and source records attributed to W J Wasserman.

23 records · Page 2Linked to original sources
PubMed1976

A cytoplasmic factor promoting oocyte maturation: its extraction and preliminary characterization.

Cytoplasm of maturing amphibian oocytes possesses a factor that induces germinal vesicle breakdown. This factor was extracted from Rana pipiens eggs and assayed by microinjection in Xenopus laevis oocytes. The activity of this factor is Mg-dependent, Ca-sensitive, and associated with heat-labile protein. Centrifugation on a sucrose density gradient revealed that the factor exists in three different molecular sizes.

Animals↗
PubMed1975

Initiation of meiotic maturation in Xenopus laevis oocytes by the combination of divalent cations and ionophore A23187.

Meiotic maturation was induced in Xenopus laevis oocytes when the external Ca++ or Mg++ ion concentration was raised above 5 mM in the presence of the ionophore. Ionophore-divalent cation-induced maturation appears to be due to the stimulation of the oocyte itself. Cytoplasm of responding oocytes induced maturation when microinjected into ovarian oocytes. Cycloheximid, an inhibitor of progesterone-induced maturation, inhibited the maturational response induced by the ionophore and divalent cations. Ethidium bromide, an inhibitor of the follicular response to human chorionic gonadotropin, had no effect. The possible roles that Ca++ and Mg++ may play in the initiation of maturation are discussed.

Animals↗