The morphology of the preimaginal stages of Enochrus Thomson (Coleoptera: Hydrophilidae) is investigated. Descriptions and detailed illustrations of the egg cases, all three larval instars, and pupae of the Neotropical species E. (Hugoscottia) variegatus (Steinheil, 1869) and E. (Methydrus) vulgaris (Steinheil, 1869) are presented. The larval morphology of these species is studied on the basis ...

The eggshell of the hen is a highly ordered and mineralised structure, which is sequentially deposited within an acellular milieu – the uterine fluid secreted by the distal oviduct. Spherulitic crystal growth of calcite is initiated on organic aggregates on surface of the eggshell membranes, followed by competition between radial crystallites for space to form a compact columnar biomineral. The...

The morphological effects of epidermal growth factor (EGF) on human carcinoma cells A-431 have been examined by scanning electron microscopy. These flat polygonal cells normally exhibit only small membrane folds, but show extensive ruffling and extension of filopodia within 5 min of exposure to EGF at 37 degrees C. This ruffling activity is transient, subsiding within another 5--15 min, but sev...

Standardized sperm concentration and volume:volume extension were compared as dilution rates for canine semen freezing. Six proven stud dogs were submitted to two seminal collections by manual stimulation. Semen was evaluated and extended in tris plus egg-yolk and glycerol according to two different dilution rates. The first one was based on a standardized sperm concentration of 200x10 spermato...

Multilamellar stacking seen in negatively stained lipid vesicle-tubulin mixtures has been attributed to lipid-protein interactions (Caron, J. M., and R. D. Berlin, 1979, J. Cell Biol. 81:665-671). We show that this stacking is produced by the phosphotungstic acid used for staining, independent of the presence of tubulin in the sample. The morphology of negatively stained single bilayer vesicles...

The levels of neutralizing antibody to a pathogen are an effective indicator to predict efficacy of a vaccine in trial. And yet not all the trial vaccines are in line with the theory. Using dengue virus (DENV) to investigate the viral morphology affecting the predictive value, we evaluated the viral morphology in acute dengue plasma compared to that of Vero cells derived DENV. The virions in pl...

Several studies of eye morphology have analysed macroevolutionary patterns in the diversity of eyes, and although these studies are often linked to environment or behaviour, they provide only indirect evidence of selection. Specific data to show the microevolutionary potential for adaptation by natural selection in eye morphology have been lacking. We document directional selection on eye size,...

If ‘the aim of biomineralisation is stability’, then with reference to the hen’s egg such stability is essential if the calcified package, constructed over a period of 20 hours, is to meet the demands of the developing embryo or withstand the rigours of selection, packaging and travel en route to the table. The pattern of mineralisation in which calcite, the most stable polymorph of calcium car...