WAVELENGTH AND TIME EVOLUTION OF MULTIPLE STIMULATED RAMAN SPECTRA IN CCl4CCl_{4} EXCITED BY AN INTENSE PICOSECOND LASER PULSE

Author Institution: Section Biology, Institut de Radium; Laboratoire de Photosynthese, GIF; P.N. Lebedev Physical Institute, USSRBy focussing a giant laser pulse, delivered by a mode-locked Nd-YAG laser, Into $CCl_{4}$, under specified conditions, a discrete train of stimulated Raman bands was observed. On the anti-Stokes side for instance, using a multichannel spectroscopy method, over 30 bands of very high intensity were recorded, ranging from 1.06 $\mu m$ to below 400 nm. Under the conditions of the experiments, no continuum was detected between the bands. The time evolutions of the various bands were simultaneously examined, using a high speed deflection camera. The following features were observed: 1) the durations of the stimulated Raman bands are always less than that of the excitation laser pulse (either $1.06\mu m$ or 532 nm), 2) the durations of the individual, stimulated Raman bands decrease steadily, as the bands are more distant from the excitation line, 3) the durations of the bands which are far away from the excitation line are below the time resolution capability of the camera used, i.e., $\sim$6 ps

Centrosomes in the zebrafish (Danio rerio): a review including the related basal body

Ever since Edouard Van Beneden and Theodor Boveri first formally described the centrosome in the late 1800s, it has captivated cell biologists. The name clearly indicated its central importance to cell functioning, even to these early investigators. We now know of its role as a major microtubule-organizing center (MTOC) and of its dynamic roles in cell division, vesicle trafficking and for its relative, the basal body, ciliogenesis. While centrosomes are found in most animal cells, notably it is absent in most oocytes and higher plant cells. Nevertheless, it appears that critical components of the centrosome act as MTOCs in these cells as well. The zebrafish has emerged as an exciting and promising new model organism, primarily due to the pioneering efforts of George Streisinger to use zebrafish in genetic studies and due to Christiane Nusslein-Volhard, Wolfgang Driever and their teams of collaborators, who applied forward genetics to elicit a large number of mutant lines. The transparency and rapid external development of the embryo allow for experiments not easily done in other vertebrates. The ease of producing transgenic lines, often with the use of fluorescent reporters, and gene knockdowns with antisense morpholinos further contributes to the appeal of the model as an experimental system. The added advantage of high-throughput screening of small-molecule libraries, as well as the ease of mass rearing together with low cost, makes the zebrafish a true frontrunner as a model vertebrate organism. The zebrafish has a body plan shared by all vertebrates, including humans. This conservation of body plan provides added significance to the existing lines of zebrafish as human disease models and adds an impetus to the ongoing efforts to develop new models. In this review, the current state of knowledge about the centrosome in the zebrafish model is explored. Also, studies on the related basal body in zebrafish and their relationship to ciliogenesis are reviewed