Extract prepared from activated Xenopus eggs is capable of reconstituting nuclei from added DNA or chromatin. We have incubated such extract in the absence of DNA and found that numerous flattened membrane cisternae containing densely spaced pore complexes (annulate lamellae) formed de novo. By electron and immunofluorescence microscopy employing a pore complex-specific antibody we followed the...

[1] Shear waves that traverse the lowermost mantle exhibit polarization anomalies and waveform complexities that indicate the presence of complex velocity structure above the core-mantle boundary. Synthetic seismograms for horizontally and vertically polarized shear waves (SH and SV, respectively) are computed using the reflectivity method for structures with low-velocity sheets (‘‘lamellae’’),...

PURPOSE To map the collagen orientation and relative distribution of collagen fibrillar mass in keratoconus corneal buttons. METHODS Structural analysis was performed by obtaining synchrotron x-ray scattering patterns across the samples at 0.25-mm intervals. The patterns were analyzed to produce two-dimensional maps of the orientation of the lamellae and of the distribution of total and prefe...

At temperatures below 15°C the gill lamellae of goldfish (Carassius auratus) are largely covered by an interlamellar cell mass (ILCM) which decreases the functional surface area of the gill. The presence of the ILCM in goldfish acclimated to cold water conceivably could lead to a covering of the neuroepithelial cells (NECs), which are believed to be important for sensing ambient O₂ and CO₂ leve...

The pigment and acyl lipid composition ofphotochemically active stroma lamellae and inside-out photosystem II vesicles have been investigated. Mechanical disruption followed by phase partitioning in an aqueous two phase system resulted in a clean separation of the photosystems. A qualitative and quantitative determination of the pigment content was achieved using reversed-phase high performance...

Atresia is the process through which non-selectable oocytes are eliminated; it involves apoptosis and/or autophagy. This study used immunohistochemical and ultrastructural techniques to characterize the lamellae present in the cytoplasm of oocytes in follicles in the process of atresia in prepubertal and adult Wistar rats. The results indicate that the lamellae are positive to tubulin and myosi...

introduction: the regulation of the body fluid content (osmoregulation) of an aquatic animal, is performed by several organs. in fish, osmoregulatory mechanisms are based on the function of specialized cells (ionocytes) located in various tissues and organs including gills. na+, k+-atpase is one of the main osmoregulatory enzymes enabling the use of atp as a source of energy for ion transport t...

Ferricyanide was used as a Hill oxidant to localize the site of photoreduction in chloroplast lamellae. The ferrocyanide formed on illumination was complexed with copper ions to form insoluble, electron-dense precipitates of Cu ferrocyanide, which can be easily seen in unstained preparations in the electron microscope. Control experiments showed no precipitates in the dark, at zero time, in the...