Phospholipid turnover and ultrastructural correlates during spontaneous germinal vesicle breakdown of the bovine oocyte: Effects of a cyclic AMP phosphodiesterase inhibitor

Journal Article · Thu Aug 01 00:00:00 EDT 1991 · Developmental Biology; (United States)

DOI:https://doi.org/10.1016/0012-1606(91)90247-Z· OSTI ID:5229439

Homa, S T; Webster, S D; Russell, R K ^[1]

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1. Arizona State University, Tempe (USA)

The turnover of (32P)orthophosphate in bovine oocyte phospholipids was studied during the early stages of spontaneous meiotic maturation, and during inhibition of this process by the cAMP phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine (IBMX). Radioactive lipids were separated by TLC and the meiotic stage was determined cytogenetically. Ultrastructure of the nuclear membrane was examined using transmission EM. During the commitment period to meiotic resumption, which precedes germinal vesicle breakdown (GVBD), small localized convolutions appeared in the intact nuclear membrane. This was accompanied by a decrease in (32P)phosphatidic acid (PA) and an increase in (32P)-phosphatidylcholine (PC). This was followed by extensive convolutions, and subsequent dissociation, of the nuclear membrane, concomitant with a tremendous surge in (32P)PC and (32P)phosphatidylethanolamine (PE). The cAMP-mediated maintenance of meiotic arrest involved retention of entire nuclear envelope integrity and total inhibition of the surge in (32P)PC and (32P)PE which accompanied GVBD. The increase in (32P)phosphatidylinositol (PI) associated with all stages of early meiotic resumption was unaffected by IBMX. Microinjection of heparin inhibited GVBD, and injection of inositol 1,4,5-trisphosphate (IP3) overrode IBMX-maintained meiotic arrest in almost 40% of the oocytes. The results suggest that there may be several functions for phospholipid turnover in the regulation of spontaneous meiotic resumption in the bovine oocyte. The first precedes the commitment period, and involves IP3 generation to serve as the primary signal for meiotic resumption. The second occurs concomitant with the commitment period, is unaffected by the level of intracellular cAMP, and is associated with the general turnover of phospholipid.

• OSTI ID: 5229439
• Journal Information: Developmental Biology; (United States), Journal Name: Developmental Biology; (United States) Vol. 146:2; ISSN 0012-1606; ISSN DEBIA
• Country of Publication: United States
• Language: English

Related Subjects

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550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
AMP
ANIMALS
ANTICOAGULANTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CARBOHYDRATES
CATTLE
CELL CONSTITUENTS
CELL DIFFERENTIATION
CELL DIVISION
CELL MEMBRANES
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
DRUGS
ENZYME INHIBITORS
ESTERS
GERM CELLS
HEMATOLOGIC AGENTS
HEPARIN
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
LIPIDS
MAMMALS
MEIOSIS
MEMBRANES
METABOLISM
MUCOPOLYSACCHARIDES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
OOCYTES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHOLIPIDS
PHOSPHORUS 32
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
POLYSACCHARIDES
PREGNANCY
RADIOISOTOPES
REACTION KINETICS
RUMINANTS
SACCHARIDES
SEPARATION PROCESSES
THIN-LAYER CHROMATOGRAPHY
TRACER TECHNIQUES
VERTEBRATES