Back to Search Start Over

Developmental changes in localization of the main ganglioside during sea urchin embryogenesis

Developmental changes in localization of the main ganglioside during sea urchin embryogenesis

Authors :
Toshihiro Yamamoto
Kazuyoshi Chiba
Maiko Nezuo
Tetsuo Shiba
Hidehiko Shogomori
Tadashi Teshima
Motonori Hoshi
Source :
Glycobiology. 10(11)
Publication Year :
2000

Abstract

Ganglioside M5 (NeuGcalpha2-6Glcbeta1-1'Cer), the main ganglioside in sea urchin and sand dollar eggs, exists mainly in the endoplasmic reticulum and yolk granules in unfertilized eggs. To study the localization of ganglioside M5 after fertilization, early embryos were stained with an anti-ganglioside M5 monoclonal antibody. Using immunofluorescent and immunoelectron microscopy, intense label was observed in the outer surface and cytoplasm of embryos. These results indicate that ganglioside M5 was secreted during embryogenesis and localized in the extracellular matrix (ECM). When living embryos were incubated in sea water containing 7-nitrobenz-2-oxa-1,3-diazole labeled-ganglioside M5 (NBD-M5), the ECM and plasma membrane were strongly stained. Since the localization of NBD-M5 in the ECM was similar to that of extracellular M5, NBD-M5 was likely to be useful to examine the fate of extracellular ganglioside M5. Interestingly, NBD-M5 was incorporated in subcortical vesicles during embryogenesis, suggesting that the extracellular ganglioside M5 is transported into the cytoplasm. When fertilized eggs were incubated with NBD-M5 and tetramethylrhodamine dextran (a marker dye for endocytotic vesicles), colocalization of the dyes was observed in the vesicles. Thus, it was concluded that NBD-M5 in the ECM and/or plasma membrane was internalized in the cells by endocytosis, suggesting that extracellular M5 is transported from the ECM to endocytotic vesicles.

Details

ISSN :
09596658
Volume :
10
Issue :
11
Database :
OpenAIRE
Journal :
Glycobiology
Accession number :
edsair.doi.dedup.....45699cabedccbcee5a519a135bd5e0fd