Identification of the gene for vitamin K epoxide reductase

Vitamin K epoxide reductase (VKOR) is the target of warfarin, the most widely prescribed anticoagulant for thromboembolic disorders. Although estimated to prevent twenty strokes per induced bleeding episode, warfarin is under-used because of the difficulty of controlling dosage and the fear of inducing bleeding. Although identified in 1974 (ref. 2), the enzyme has yet to be purified or its gene identified. A positional cloning approach has become possible after the mapping of warfarin resistance to rat chromosome 1 (ref. 3) and of vitamin K-dependent protein deficiencies to the syntenic region of human chromosome 16 (ref. 4). Localization of VKOR to 190 genes within human chromosome 16p12-q21 narrowed the search to 13 genes encoding candidate transmembrane proteins, and we used short interfering RNA (siRNA) pools against individual genes to test their ability to inhibit VKOR activity in human cells. Here, we report the identification of the gene for VKOR based on specific inhibition of VKOR activity by a single siRNA pool. We confirmed that MGC11276 messenger RNA encodes VKOR through its expression in insect cells and sensitivity to warfarin. The expressed enzyme is 163 amino acids long, with at least one transmembrane domain. Identification of the VKOR gene extends our understanding of blood clotting, and should facilitate development of new anticoagulant drugs.     

Detection of human antigens on the surface of mouse cells transformed by chromosome transfer]

Mouse embryo cells, transformed in vitro by the transfer of chromosomes from HeLa human tumour cells, express a surface antigen (s) also found on HeLa cells. This antigen(s), which has been detected both by indirect immunofluoresence and by a 125I-protein A binding assay, is not an antigen(s) shared by both Human and Mouse cells.     

Pigment formation in sensory cells ofAplysia l

Summary The yellow-brown pigment present in the sensory cells ofAplysia limacina was studied using light and electron microscopy. The ultrastructure, the high carotenoid content and the presence in neurons for which a turnover process has been hypothesized, indicate that these pigments are cytosomes, organelles involved in the production of energy in anaerobiosis.This investigation was conducted at the Zoological Station of Naples.     

Cell transformation in vitro by transfer of isolated metaphase chromosomes]

Human and murine cells can be transformed in vitro following transfer of chromosomes (transfection) isolated from tumour (HeLa) or SV40-transformed (WI98VaD) human cells. An abortive transformation of Mouse cells is observed in soft-agar medium. An instability of the transformed phenotype is exhibited by the transfected human cells, following the isolation of colonies growing in soft-agar or low-serum medium. Nevertheless, two transformed cell lines (809 ch. VaD, Cl.5P and Cl.6P) could be established in culture.     

Fluorinated analogs of insect sex pheromones

Summary The syntheses of fluorinated mimics of pheromones ofSpodoptera littoralis, Diparopsis castanea, Laspeyresia pomonella, Bombyx mori andThaumetopoea pityocampa are described. These analogs showed biological activities similar to those of the natural pheromones in laboratory assays (EAG).We gratefully acknowledge Comisión Asesora de Investigación Cientifica y Técnica for financial support (Grant No. 3296/79) and Consejo Superior de Investigaciones Cientificas for predoctoral and postdoctoral fellowship (to G.F. and M.R.). We also thank Mr J. Baltá and Ms R. Murgó for their collaboration in the EAG work.     

Parasites of the Lessepsian invasive fish Lagocephalus sceleratus (Gmelin 1789) in the eastern Mediterranean Sea

Lagocephalus sceleratus, is a Lessepsian invasive fish species introduced into the Mediterranean Sea through the Suez Canal. This study investigated it as host of parasites. Out of 41 individuals caught from northern and southern locations of the eastern Aegean Sea, nine were found to host parasites. Gnathia sp. praniza larva, an ectoparasite, was associated with severe damage of the primary and secondary structures of the gills and it was found in one specimen (prevalence 2.4%). Regarding endoparasites, Anisakis type I third-stage larvae were found in two specimens (prevalence 4.9%). In addition, adult nematodes of Hysterothylacium aduncum were found in another six specimens (prevalence 14.6%). Lagocephalus sceleratus is a new host for some indigenous parasites, with low host specificity, in the Mediterranean Sea, providing an additional niche for the success and increase of local populations of these parasites and, to our knowledge, this is the first record of L. sceleratus parasites in this area. Whether these parasites can control the invasion success of L. sceleratus needs to be further investigated. However, the low mean intensity of infection found in this study does not support such control.