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Type Member (type + member)
Selected AbstractsBeet yellows virus: the importance of being differentMOLECULAR PLANT PATHOLOGY, Issue 2 2003Valerian V. Dolja SUMMARY Taxonomic relationship: Type member of the genus Closterovirus, family Closteroviridae. A member of the alphavirus-like supergroup of positive-strand RNA viruses. Physical properties: Virions are flexuous filaments of ,1300 nm in length and ,12 nm in diameter that are made up of a ,15.5 kb RNA and five proteins. The major capsid protein forms virion body of helical symmetry that constitutes ,95% of the virion length. The short virion tail is assembled by the minor capsid protein, Hsp70-homologue, ,64-kDa protein, and ,20-kDa protein. Viral proteins: The 5,-most ORFs 1a and 1b encode leader proteinase and RNA replicase. The remaining ORFs 2,8 are expressed by subgenomic mRNAs that encode 6-kDa membrane protein, Hsp70 homologue, ,64-kDa protein, minor and major capsid proteins, ,20-kDa protein, and ,21-kDa protein, respectively. Hosts: The principal crop plants affected by Beet yellows virus (BYV) are sugar beet (Beta vulgaris) and spinach (Spinacea oleracea). In addition, BYV was reported to infect ,120 species in 15 families. Most suitable propagation species are Nicotiana benthamiana, Tetragonia expansa, and Claytonia perfoliata. [source] Monoclonal Antibodies against the Recombinant Nucleocapsid Protein of Tomato spotted wilt virus and its Application in Virus DetectionJOURNAL OF PHYTOPATHOLOGY, Issue 6 2009Jianxiang Wu Abstract Tomato spotted wilt virus (TSWV) is the type member of the tospovirus genus and causes significant losses in a wide range of economically important ornamental and vegetable crops worldwide. The nucleocapsid gene, located on the ambisense S RNA segment of TSWV was expressed in Escherichia coli using pET-32a as vector and correct expression of recombinant protein was confirmed by Western blot using an anti-TSWV monoclonal antibody (MAb). The recombinant protein was purified using Ni-NTA agarose and the purified protein was used for the production of MAbs. Three murine MAbs against the recombinant nucleocapsid protein were produced. Triple antibody sandwich enzyme-linked immunosorbent assay and immunocapture RT-PCR methods were then established for reliable and efficient detection of TSWV using the produced MAbs. [source] Cauliflower mosaic virus: still in the newsMOLECULAR PLANT PATHOLOGY, Issue 6 2002Muriel Haas SUMMARY Taxonomic relationship:Cauliflower mosaic virus (CaMV) is the type member of the Caulimovirus genus in the Caulimoviridae family, which comprises five other genera. CaMV replicates its DNA genome by reverse transcription of a pregenomic RNA and thus belongs to the pararetrovirus supergroup, which includes the Hepadnaviridae family infecting vertebrates. Physical properties:, Virions are non-enveloped isometric particles, 53 nm in diameter (Fig. 1). They are constituted by 420 capsid protein subunits organized following T= 7 icosahedral symmetry (Cheng, R.H., Olson, N.H. and Baker, T.S. (1992) Cauliflower mosaic virus: a 420 subunit (T= 7), multilayer structure. Virology, 16, 655,668). The genome consists of a double-stranded circular DNA of approximately 8000 bp that is embedded in the inner surface of the capsid. Figure 1. Electron micrograph of CaMV virions. Courtesy of J. Menissier de Murcia, Ecole Supérieure de Biotechnologie de Strasbourg. Viral proteins: The CaMV genome encodes six proteins, a cell-to-cell movement protein (P1), two aphid transmission factors (P2 and P3), the precursor of the capsid proteins (P4), a polyprotein precursor of proteinase, reverse transcriptase and ribonuclease H (P5) and an inclusion body protein/translation transactivator (P6). Hosts: The host range of CaMV is limited to plants of the Cruciferae family, i.e. Brassicae species and Arabidopsis thaliana, but some viral strains can also infect solanaceous plants. In nature, CaMV is transmitted by aphids in a non-circulative manner. [source] The empirical upper limit for mass loss of cool main sequence starsASTRONOMISCHE NACHRICHTEN, Issue 4 2008A. Lednicka Abstract The knowledge of mass loss rates due to thermal winds in cool dwarfs is of crucial importance for modeling the evolution of physical parameters of main sequence single and binary stars. Very few, sometimes contradictory, measurements of such mass loss rates exist up to now. We present a new, independent method of measuring an amount of mass lost by a star during its past life. It is based on the comparison of the present mass distribution of solar type stars in an open cluster with the calculated distribution under an assumption that stars with masses lower than Mlim have lost an amount of mass equal to ,M. The actual value of ,M or its upper limit is found from the best fit. Analysis of four clusters: Pleiades, NGC 6996, Hyades and Praesepe gave upper limits for ,M in three of them and the inconclusive result for Pleiades. The most restrictive limit was obtained for Praesepe indicating that the average mass loss rate of cool dwarfs in this cluster was lower than 6 × 10,11 M,/yr. With more accurate mass determinations of the solar type members of selected open clusters, including those of spectral type K, the method will provide more stringent limits for mass loss of cool dwarfs. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||