A spontaneous membrane assembly process has been postulated to account for the rapid perigranular membrane enlargement which occurs during mast cell secretory granule activation. This process requires the presence of a phospholipid store in the quiescent granule. By using purified granules with intact membranes we have determined the total phospholipid content of the average quiescent granule. ...

by a short BrdU pulse, indicating that prevention of Bmi1 downregulation does not drive granule cells back into the cell cycle. No tumours were observed in two aging cohorts of transgenic mice derived from separate founder lines. However, these mice display an increase in astrocytes with the type II morphology in vitro compared to wild-type littermates. Cultures of FACSorted Math1-GFP+ granule ...

T HE CYTOPLASMIC GRANULES of eosinophils may be considered a form of lysosome, for they are membrane bounded structures containing, among other substances, hydrolytic enzymes.’ These granules appear in the immature cell as large membrane bounded structures with a homogeneous electron dense content; as the cell matures, a crystalloid inclusion commonly develops within the granule.2.3 Electron mi...

Germ cell formation in Drosophila relies on polar granules, which are large ribonucleoprotein complexes found at the posterior end of the embryo. The granules undergo characteristic changes in morphology during development, including the assembly of multiple spherical bodies from smaller precursors. Several polar granule components, both protein and RNA, have been identified. One of these, the ...

Recent studies suggest that multivesicular bodies are an intermediate stage in the formation of alpha-granules. In contrast, the kinetics and mode of appearance of dense granules during megakaryocytic maturation has remained poorly understood. Immunoelectron microscopy was used to monitor the appearance of dense granular markers (granulophysin and serotonin) on cryosections of human megakaryocy...

Germ granules are germ lineage-specific ribonucleoprotein (RNP) complexes, but how they are assembled and specifically segregated to germ lineage cells remains unclear. Here, we show that the PGL proteins PGL-1 and PGL-3 serve as the scaffold for germ granule formation in Caenorhabditis elegans. Using cultured mammalian cells, we found that PGL proteins have the ability to self-associate and re...