This scanning electron microscope image of the tarsal claw of the horsefly Tabanus sulcifrons juxtaposes the complexity and simplicity of “nature’s Velcro.” The menacing sturdiness of the tarsal claws contrasts with the delicate nature of the tarsal pad, with fine, hooked hairs that allow the fly to hold on to animal fur.
Video 8. Single and double centrosome ablations in a sand dollar embryo coexpressing ensconsin-3xGFP (cyan) and mC-H2B (yellow). Time-lapse sequence of single confocal sections (Atto CARV). Video corresponds to Fig. S5 B. Real times are indicated, and the video is encoded at 15 frames/s. Bar, 25 µm.
Animal cells decide where to build the cytokinetic apparatus by sensing the position of the mitotic spindle. Reflecting a long-standing presumption that a furrow-inducing stimulus travels from spindle to cortex via microtubules, debate continues about which microtubules, and in what geometry, are essential for accurate cytokinesis.
In normal cells, the cytokinetic apparatus forms in a region of lower cortical microtubule density. Ablation of a single centrosome displaces furrows away from the remaining centrosome; ablation of both centrosomes causes broad, inefficient furrowing.
Living Volvox colony at 100x magnification, differential interference contrast, by Mr Wim van Egmond
Needless to say, microscopy has progressed radically since Leeuwenhoek first observed his “animalcules” through lenses.
It is now possible to dissect cells into their various microscopic components, aiding not only in modeling and visualisation but also treatment and the advancement of research. In the image above, scientists used a technique called stochastic optical reconstruction microscopy (STORM) to peer deeper into a kidney cell. Objects of interest – in this case a protein called actin involved in cell movement – are tagged with fluorescent markers, which light up under laser light. This composite image is formed from 230,000 frames and is detailed enough to illuminate individual actin fibres, which are less than a millionth of a centimetre thick. Such high resolution can reveal the effects of a disease or a genetic fault in the finest detail - advancing research and treatment to a whole new level simply through the power of visualisation.
From NSF:
This scanning electron micrograph shows the various adhesive hairs found on the footpad of the dock beetle (Gastrophysa viridula). The feet of the green dock beetle are covered with thousands of tiny adhesive hairs, each no wider than 5 microns (1/200th of a millimetre) across, that allow the beetle to climb, even over molecularly smooth substrates. Visible in the image are two distinct hair morphologies, both pointed hairs and hairs with flattened (disc-like) tips allowing the insect to peel each contact from the surface when it wants to detach. Recent research has shed new light on the mechanisms used by beetles and other insects to run across smooth surfaces.
Chick embryo at 6x magnification, by Tomas Pais de Azevedo of Universidade de Lisboa in Portugal.
By Dr. Sonja Pyott
Department of Biology and Marine Biology
University of North Carolina, Wilmington
Wilmington, NC, USA
Specimen: Cochlea and Hair Cells
Technique: ConfocalThis confocal microscopy image of the organ of Corti is just stunning. Judges at the Olympus Bioscapes Digital Imaging Competition thought so too, and awarded Dr. Sonja Pyott 4th prize in the contest.
