ISSN:
1432-0878
Keywords:
Membrane particles
;
Cockroach hemocytes
;
Freeze-fracture
;
Electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Freeze-fracture studies were conducted on the membranes of normal cockroach hemocytes. The plasmalemma is asymmetric with the A fracture face containing 80–100 Å membrane intercalated particles at a concentration of ∼2500/μ2. The B fracture face contains 120–150 Å particles with a relatively low density (∼800/μ2). The nuclear envelope displays an asymmetry with the A fracture face containing ∼1500 particles/μ2 and the B face containing ∼300/μ 2. No significant particle size differences were observed in nuclear envelope fracture faces. Two types of symmetric membranes were also found in these cells. Both A and B fracture faces of the membrane surrounding the numerous cytoplasmic inclusion bodies contain particle sizes and concentrations similar to the B face of the plasmalemma. A second type of symmetry was observed in cells apparently engaged in “exocytosis”. Vesicles (∼0.1 μD) from this process were completely particle free on both fracture faces. Such particle free vesicles could be found in the cytoplasm, attached to the plasmalemma, or completely separated from the cell.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00224548
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