SummaryThe repair of injured tissue must occur rapidly to prevent microbial invasion and maintain tissue integrity. Epithelial tissues in particular, which serve as a barrier against the external environment, must repair efficiently in order to restore their primary function. Here we analyze the effect of different parameters on the epithelial wound repair process in the late stage Drosophila embryo using in vivo wound assays, expression of cytoskeleton and membrane markers, and mutant analysis. We define four distinct phases in the repair process, expansion, coalescence, contraction and closure, and describe the molecular dynamics of each phase. Specifically, we find that myosin, E-cadherin, Echinoid, the plasma membrane, microtubules and the Cdc42 small GTPase respond dynamically during wound repair. We demonstrate that perturbations of each of these components result in specific impairments to the wound healing process. Our results show that embryonic epithelial wound repair is mediated by two simultaneously acting mechanisms: crawling driven by cellular protrusions and actomyosin ring contraction along the leading edge of the wound.

Wound repair on the cellular and multicellular levels is essential to the survival of complex organisms. In order to avoid further damage, prevent infection, and restore normal function, cells and tissues must rapidly seal and remodel the wounded area. The cytoskeleton is an important component of wound repair, needed for actomyosin contraction, recruitment of repair machineries, and cell migration. Recent use of model systems and high-resolution microscopy has provided new insight into molecular aspects of the cytoskeletal response during wound repair. Here we discuss the role of the cytoskeleton in single cell, embryonic, and adult repair, as well as the striking resemblance of these processes to normal developmental events and many diseases.

SUMMARY Natural killer (NK) cells eliminate cancer and virus-infected cells through cytolytic activity. The last step in NK cell cytotoxicity, resulting in exocytosis of granule content, requires fusion of lytic granules with the plasma membrane. Proteins from the SNARE family mediate membrane fusion events in the cell. Here we show that NK cells express all members of the R-SNARE subgroup. Two of these R-SNARE proteins, VAMP4 and VAMP7, co-localize with lytic granules during cytotoxic interactions. However, only VAMP7 associates with perforin-containing granules in non-activated cells, indicating that the two VAMPs have different functions in exocytosis. Using both the tumor NK cell line, YTS, and peripheral NK cells we show that disruption of expression of either VAMP4 or VAMP7 inhibits release of lytic granules and severely impairs NK cell cytotoxic activity. Furthermore, VAMP7 but not VAMP4 is involved in IFNγ secretion in NK cells, indicating that VAMP7 is involved in many fusion processes and thus plays a more general function in NK cell activity than VAMP4.

Scope: Expands FORTRAN's capabilities by providing subroutines and functions for dynamic storage allocation, virtual memory, data structuring, list-processing, string-processing, sorting and ranking, statistical and matrix operators. Method: DYSTAL consists of some 81Yodd subroutines and functions written in Basic FORTRAN IV. A program written in DYSTAL consists of numerous calls to DYSTAL functions and subroutines. An early version of DYSTAL II was tested on an IBM 360/50 and a more recent version (1970) on an IBM 1130. Work is in progress on a two-byte integer version for smaller computers. Can be implemented on other machines. Scope:We propose to do a feasibility study to see if the role of language in the formation of nonconscious belief systems can be ascertained. The language we are focusing on is American English and the first ideology we will examine is that of male supremacy. If this proves successful, language characteristics of other ideologies will be examined. Method: 1) An in-depth literature search of related psycholinguistic studies and linguistic etymological studies to delimit sex-related terms.2) The application of Exposure Theory and the frequency distribution of sex-related terms. 3) A computer analysis of selected texts to reveal the frequency distribution of sex-related terms in age-graded material. 4) An experimental study of perceived sexuality in specially prepared texts with male, female, and neuter biaso, s, and select commercial texts.

Natural killer (NK) cells kill cancer and virus-infected cells through their cytolytic activity. The last step in NK cell cytotoxicity, fusion of lytic granules with the plasma membrane resulting in exocytosis of granule content, is still poorly understood. Proteins from the SNARE family mediate all membrane fusion events in the cell. Here we show that NK cells express all seven members of the R-SNARE subgroup. Two of these R-SNARE proteins, VAMP4 and VAMP7, are associated with lytic granules during cytotoxic interactions. However, only VAMP7 co-localizes with granules in non-activated cells. The differences in co-localization of these two R-SNARE proteins, with respect to perforin-containing cytotoxic granules, indicate that they have different functions in exocytosis. Using the tumor NK cell line, YTS, we show that RNAi-mediated disruption of expression of either VAMP4 or VAMP7 inhibits release of lytic granules and severely impairs NK cell cytotoxic activity. Furthermore, VAMP7 but not VAMP4 is involved in cytokine secretion and endocytosis in NK cells, indicating that VAMP7 is involved in many fusion processes and thus plays a more general function in NK cell activity than VAMP4.