Potato virus Y (PVY) has become a serious problem for the seed potato industry, with increased incidence and rejection of seed lots submitted for certification. New PVY strains and strain variants have emerged in recent decades in Europe and North America, including the PVY strain that causes veinal necrosis in tobacco, and strain variants that represent one or three recombination events between the common strain (PVY) and PVY. Several reverse transcription-polymerase chain reaction (RT-PCR) assays have been described that characterize PVY isolates as to strain type, but they are limited in their ability to detect some combinations of mixed strain infections.
View Article and Find Full Text PDFThe Drosophila Mitogen Activated Protein Kinase (MAPK) Rolled is a key regulator of developmental signaling, relaying information from the cytoplasm into the nucleus. Cytoplasmic MEK phosphorylates MAPK (pMAPK), which then dimerizes and translocates to the nucleus where it regulates transcription factors. In cell culture, MAPK nuclear translocation directly follows phosphorylation, but in developing tissues pMAPK can be held in the cytoplasm for extended periods (hours).
View Article and Find Full Text PDFPurpose: Mullerian inhibiting substance (MIS) is a glycoprotein hormone that causes Mullerian duct regression in male embryos. In short-term experiments, recombinant human MIS (rhMIS) inhibits xenotransplanted human ovarian cancer cell lines that are thought to be of Mullerian origin. Because this highly lethal cancer has a high recurrence rate after conventional chemotherapy, new treatments are warranted.
View Article and Find Full Text PDFMitogen-activated protein kinases (MAPKs) phosphorylate target proteins in both the cytoplasm and nucleus, and a strong correlation exists between the subcellular localization of MAPK and resulting cellular responses. It was thought that MAPK phosphorylation was always followed by rapid nuclear translocation. However, we and others have found that MAPK phosphorylation is not always sufficient for nuclear translocation in vivo.
View Article and Find Full Text PDFIntestinal development and homeostasis rely on the coordination of proliferation and differentiation of the epithelium. To better understand this process, we are studying Rbm19, a gene expressed in the gut epithelium that is essential for intestinal morphogenesis and differentiation in the zebrafish (Development 130, 3917). Here we analyzed the expression of Rbm19 in several biological contexts that feature proliferation/differentiation cell fate decisions.
View Article and Find Full Text PDFThe Drosophila PS1 and PS2 integrins are required to maintain the connection between the dorsal and ventral wing epithelia. If alphaPS subunits are inappropriately expressed during early pupariation, the epithelia separate, causing a wing blister. Two lines of evidence indicate that this apparent loss-of-function phenotype is not a dominant negative effect, but is due to inappropriate expression of functional integrins: wing blisters are not generated efficiently by misexpression of loss-of-function alphaPS2 subunits with mutations that inhibit ligand binding, and gain-of-function, hyperactivated mutant alphaPS2 proteins cause blistering at expression levels well below those required by wild-type proteins.
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