ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
A study of the uptake of exogenous proteins, peroxidase, ferritin, and myoglobin by rabbit blastomeres of different developmental stages was undertaken to determine some of the means by which these stages ingest protein. Exposure of embryos in preimplantation stages, ranging from fertilized ovum to late blastocyst, was carried out in vitro with selected in vivo controls. Blastomeres of early cleavage stages up to the morula show little uptake of peroxidase. However, the endocytosis of peroxidase greatly increases with the morula stages and continues at an elevated level through the blastocyst stages. The uptake of the tracer is initially accomplished via micropinocytotic vesicles and tubules and can have several subsequent fates. The tracer can pass into larger vacuoles and be transported into the cavity of the blastocyst, or can pass into multivesicular bodies where it is presumably degraded by the lysosomal system for cellular use. The use of myoglobin at selected blastocyst stages yielded results similar to those obtained with peroxidase. However, the response by the blastomeres to ferritin is different. Endocytosis of ferritin is scant at all preimplantation stages, even though the ferritin has no difficulty reaching the surface of the blastomeres. The experiment with mechanically denuded blastocysts indicated that ferritin did not adsorb to the cell surface.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091790304
