Annulate lamellae

Oocyte of Nectnrus maculosus maculosus Imertnal epithelium odls of A(yles Annulate lamellae [116]... 

Relationships between tubuloreticular structures, annulate lamellae, and cubic membranes... 

Figure 7.24 Micrographs showing typical (a)-(b) and atypical (c) appearcutce of annulate lamellae, (a) Overview showing an AL in Xenopus laevis. (b) Detail of AL in (a), (c) A rather unusual regular membrane arrangement of what can be classified as an AL. Figures (a) and (b) are reproduced from [123],and (c) from [118] with permission.

Due to the application of highly specific markers, i.e., monoclonal antibodies, the possible experimental artifacts are negligible. One problem when detecting the NPCs in the nuclear envelope are certainly those NPCs that are not yet assembled in the nuclear membrane, but are found, for example, in the annulate lamellae. Due to the high resolution in the axial direction, it will in most cases be possible to differentiate them from the nuclear envelope due to a different z position, but it cannot be excluded that some of the detected NPCs are not located in the nuclear envelope. 

Dabauvalle, M.-C., Loos, K., Merkert, H., and Scheer, U. (1991). Spontaneous assembly of pore complex-containing membranes ( annulate lamellae ) in Xenopus egg extract in the absence of chromatin. J. Cell Biol. 112, 1073-1082. 

Meier, E Miller, B., and Forbes, D. J. (1995). Nuclear pore complex assembly studied with a biochemical assay for annulate lamellae formation. J. Cell Biol 129, 1459-1472. 

Annulate lamellae (Fig. 229) are intracytoplasmic membrane systems composed of parallel arrays of cisternae bearing at regular intervals small annuli or fenestrae. As shown by electron microscopy, the structure of the aimulate lamellae pore complex is similar to that of the pore complexes of the nuclear envelope. When melatonin was administered to rats or when rats were kept in darkness Freire and Cardinali (1975) observed changes in the ultra-... 

Fig. 229. Annulate lamellae and damaged mitochondria (swelling and cristolysis) in a repetitively reoxygenated pineal cell (block 1211) from a rat (No. 7) treated for 7 consecutive days with intraperitoneal injection of 1.5 ml Tyrode s solution per kg body weight x day. On the last 4 days of experimentation the animal was exposed to an atmosphere containing only 5 % oxygen for 30 min. Half an hour after the last exposure under pentobarbital anaesthesia (30 mg/kg), the animal was perfused from the abdominal aorta with 2.5 % glutaral-dehyde in 0.1 M sodium cacodylate buffer (pH 7.4). Postfixa-tion with 1 % osmium tetroxide in sodium cacodylate buffer. Embedded in Epon 812 and sectioned at 50 nm. Lead citrate and uranyl acetate. Plate 3395...

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