The acquisition by parasites of the capacity to infect resistant host genotypes, that is, resistance-breaking, is predicted to be hindered by across-host fitness trade-offs. All analyses of costs of resistance-breaking in plant viruses have focused on within-host multiplication without considering other fitness components, which may limit understanding of virus evolution. We have reported that ...

In mice vaccinated subcutaneously with different doses of virulent W.E.E. virus or with formolized vaccine, neutralizing and complement-fixing antibodies paralleled resistance to some extent yet appeared in groups in which resistance remained undetectable, persisted at a similar maximum level in spite of different titers of resistance, and after resistance had become negligible. In mice vaccina...

introduction: influenza is a contagious acute viral disease of the respiratory tract that causes fever, headache, muscle aches and cough. one of the unique features of influenza virus is antigenic variation in viral protein neuraminidase (na) which causes emergence of new virus variants. na is responsible for the release and spread of progeny virions. due to the continuous changes of na genes, ...

Following interruption of antiretroviral therapy among individuals with acquired drug resistance, preexisting drug-sensitive virus emerges relatively rapidly. In contrast, wild-type virus is not archived in individuals infected with drug-resistant human immunodeficiency virus (HIV) and thus cannot emerge rapidly in the absence of selective drug pressure. Fourteen recently HIV-infected patients ...

Virus-induced gene silencing was used to assess the function of random Nicotiana benthamiana cDNAs in disease resistance. Out of 4992 cDNAs tested from a normalized library, there were 79 that suppressed a hypersensitive response (HR) associated with Pto-mediated resistance against Pseudomonas syringae. However, only six of these clones blocked the Pto-mediated suppression of P.syringae growth....

RNA silencing in plants is a natural defense system against foreign genetic elements including viruses. This natural antiviral mechanism has been adopted to develop virus-resistant plants through expression of virus-derived double-stranded RNAs or hairpin RNAs, which in turn are processed into small interfering RNAs (siRNAs) by the host's RNA silencing machinery. While these virus-specific siRN...

the identification of molecular markers linked to leaf curl virus (clcuv) disease resistance in cotton has the potential to improve both the efficiency and the efficacy of selection in cotton breeding programs. genetic analysis suggested that clcuv resistance is controlled by a single dominant gene. in this study, an interspecific f2 population derived from a cross of gossypium barbadense and g...

Administration of neutralizing monoclonal antibody to gamma interferon increased Theiler's virus-induced demyelination and virus antigen persistence in the spinal cord in susceptible SJL/J mice and completely abrogated resistance such that all C57BL/10SNJ mice developed demyelination. These experiments support the hypothesis that gamma interferon is critically important for resistance to Theile...