Phospholipid transfer activities in toad oocytes and developing embryos. [Bufo arenarum]

Journal Article · Thu Jan 01 04:00:00 EST 1987 · J. Lipid Res.; (United States)

OSTI ID:6526686

Rusinol, A; Salomon, R A; Bloj, B

The role of lipid transfer proteins during plasma membrane biogenesis was explored. Developing amphibia embryos were used because during their growth an active plasma membrane biosynthesis occurs together with negligible mitochondrial and endoplasmic reticulum proliferation. Sonicated vesicles, containing /sup 14/C-labeled phospholipids and /sup 3/H-labeled triolein, as donor particles and cross-linked erythrocyte ghosts as acceptor particles were used to measure phospholipid transfer activities in unfertilized oocytes and in developing embryos of the toad Bufo arenarum. Phosphatidylcholine transfer activity in pH 5.1 supernatant of unfertilized oocytes was 8-fold higher than the activity found in female toad liver supernatant, but dropped steadily after fertilization. After 20 hr of development, at the stage of late blastula, the phosphatidylcholine transfer activity had dropped 4-fold. Unfertilized oocyte supernatant exhibited phosphatidylinositol and phosphatidylethanolamine transfer activity also, but at the late blastula stage the former had dropped 18-fold and the latter was no longer detectable under our assay conditions. Our results show that fertilization does not trigger a phospholipid transport process catalyzed by lipid transfer proteins. Moreover, they imply that 75% of the phosphatidylcholine transfer activity and more than 95% of the phosphatidylinositol and phosphatidylethanolamine transfer activities present in pH 5.1 supernatants of unfertilized oocytes may not be essential for toad embryo development. Our findings do not rule out, however, that a phosphatidylcholine-specific lipid transfer protein could be required for embryo early growth.

• Research Organization: INSIBIO (UNT-CONICET), San Miguel de Tucuman, Argentina
• OSTI ID: 6526686
• Journal Information: J. Lipid Res.; (United States), Journal Name: J. Lipid Res.; (United States) Vol. 1; ISSN JLPRA
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
550301* -- Cytology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
BIOCHEMICAL REACTION KINETICS
CARBON 14 COMPOUNDS
CELL CONSTITUENTS
CELL MEMBRANES
ESTERS
GERM CELLS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPIDS
MEMBRANES
METABOLISM
ONTOGENESIS
OOCYTES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
REACTION KINETICS
TOADS
TRACER TECHNIQUES
VERTEBRATES