Understanding the coevolution of hosts and parasites is one of the key challenges for evolutionary biology. In particular, it is important to understand the processes that generate and maintain variation. Here, we examine a coevolutionary model of hosts and parasites where infection does not depend on absolute rates of transmission and defense but is approximately all-or-nothing, depending on t...

Parvoviruses elaborate rugged nonenveloped icosahedral capsids of approximately 260 A in diameter that comprise just 60 copies of a common core structural polypeptide. While serving as exceptionally durable shells, capable of protecting the single-stranded DNA genome from environmental extremes, the capsid also undergoes sequential conformational changes that allow it to translocate the genome ...

As baculoviruses usually have a narrow insecticidal spectrum, knowing the mechanisms by which they control the host-range is prerequisite for improvement of their applications as pesticides. In this study, from supernatant of culture cells transfected with DNAs of an Autographa californica multiple nucleopolyhedrovirus (AcMNPV) mutant lacking the antiapoptotic gene p35 (vAc(∆P35)) and a cosmid ...

What determines which plant species are susceptible to a given plant pathogen is poorly understood. Experimental inoculations with fungal pathogens of plant leaves in a tropical rain forest show that most fungal pathogens are polyphagous but that most plant species in a local community are resistant to any given pathogen. The likelihood that a pathogen can infect two plant species decreases con...

Ample evidence suggests that all influenza viruses in mammals were probably derived from those in wild waterfowl at some time. In addition to those already established in mammals, the viruses have been transmitted to both mammals and to poultry from wild waterfowl and caused outbreaks in recent years. Experimentally, however, the viruses from one species of animals do not grow efficiently in ot...

alfalfa mosaic virus (almv) is one of the most conspicuous alfalfa viruses in the world. in order to identify the distribution, host range and molecular characterization of alfalfa mosaic virus in kerman province, 514 alfalfa samples showing mosaic, calico, mottle and malformation symptoms as well as 66 potato samples showing calico symptoms were collected from alfalfa and potato fields in kerm...