A laser scanning confocal microscope will significantly enhance and expand the research capabilities of a group of molecular, cellular, and integrative biologists at the College of William and Mary. Currently, these investigators use conventional light and epifluorescence microscopy which, due to certain inherent limitations, precludes certain types of studies. Confocal microscopy can produce optical sectioning of biological specimens and this series of optical sections can then be tomographically assembled using computer reconstruction to produce extremely precise three dimensional images that could be optically viewed through any plane. This allows for imaging fluorescent signals in both living tissues and in thick biological specimens. Confocal microscopy is extremely well suited for visualizing multiple fluorescent signals in the same cell simultaneously and allows for an accurate quantitative measurement of colocalization. The investigator can detect weak or faint images while dramatically increasing the resolution of the image compared to standard epifluorescence. Moreover, even subcellular structures or signals can be localized within a cell in the context of a tissue slice or a living embryo. The acquisition of a confocal scope will enable these investigators to conduct their current research projects more efficiently and productively as well as extend their research in new directions. This instrumentation will have a major impact on seven different research projects including (1) understanding the molecular and cellular mechanisms governing the development of brain vasculature, in particular the tissue interactions and genetic responses that give rise to the brain vasculature ; (2) investigating subnuclear trafficking of nuclear hormone receptors; (3) determining the physiological and genetic mechanisms regulating reproductive responsiveness and inhibition in prairie deermice; (4) uncovering genetic variation underlying photoresponsiveness in the white-footed mouse; (5) investigating the metaphase to anaphase transition during mitosis and meiosis in C. elegans, particularly the role of the anaphase promoting complex; (6) analyzing the functional morphology of thermoregulatory neurons in the hypothalamus in order to understand how organisms regulate their temperature; and (7) determining the genetic mechanisms regulating the activity of the Pax-5 transcription factor during B cell development. In addition, additional investigators from the Biology Department as well investigators from other disciplines including BioPsychology, Kinesiology and Applied Science, will also utilize the confocal microscope. The acquisition of this instrument will have a profound effect not only on the research capabilities of the investigators but will also have a significant educational impact at the College of William and Mary. This technology will be integrated into the cell biology, molecular biology, and neurobiology courses. A substantial number of both Master's degree students and undergraduates will utilize the confocal microscope in the course of their research.