This proposal characterizes and justifies the need to acquire a research grade high resolution transmission electron microscope. The proposed instrumentation will facilitate the research endeavors of a core group of investigators involved in studies of respiratory and reproductive biology and disease pathogenesis. Biological electron microscopy and morphologic analysis has grown from an almost purely descriptive discipline in its infancy to present day linkages with physiologic and molecular techniques from which important structure/function relationships can be derived. Modern cell biological, molecular, and physiologic techniques already are being routinely applied by the investigators named in this proposal. Additionally, each investigator named in this proposal has an established record of scholarship, productivity, and support by the NIH. Acquisition of the instrumentation described in this proposal will permit this group to obtain high resolution electron micrographs of specimens pertinent to their research thus facilitating rigorous and comprehensive analysis of their investigations. Furthermore, this group has been availed of considerable institutional support including allocation of research space, laboratory renovation, salary support, and the acquisition and support of major instrumentation. An indication of the continuing institutional commitment to this group is illustrated by this Shared Instrumentation Grant re-application relative to our initial application of 1988. In that proposal which was approved but not funded, the equipment request included a computer system for morphometry and image analysis. In the interim, the institution has provided funds for the purchase of this item which has reduced our request in this re-application by almost $10,000. Acquisition of the instrumentation described by this proposal complemented by established and continuing extramural and institutional support will favorably position this productive group of scientists for continued success.