An interspecies hybrid RNA virus is significantly more virulent than either parental virus.

An interspecies hybrid RNA virus is significantly more virulent than either parental virus.

Cucumber mosaic cucumovirus (CMV) infects a very wide range of plant species (>1000 species). We recently demonstrated that a previously undescribed gene (2b) encoded by RNA 2 of the tripartite RNA genome of CMV is required for systemic virus spread and disease induction in its hosts. Herein we report that when this CMV gene is replaced by its homologue from tomato aspermy cucumovirus (TAV), th...

Zika Virus: More Questions Than Answers

The recent Zika virus (ZIKV) outbreak has been declared a Public Health Emergency of International Concern (PHEIC) by the World Health Organization in February 2016. It started in Brazil in 2015, rapidly spread through South and Central America, and is expected to reach the continental US in the summer of 2016. The appearance of ZIKV has been connected with an increase in cases of microcephaly ...

Is human T-cell lymphotropic virus type I more clever than human immunodeficiency virus type 1?

SIR—Casseb [1] hypothesizes that human T-cell lymphotropic virus type I (HTLV-I) is “more clever” than human immunodeficiency virus type 1 (HIV-1). One of his reasons is that HTLV-I, unlike HIV-1, has “an exceptionally low capability for causing death in the host.” “Cleverness” is not a biological concept but rather an anthropomorphism. Casseb probably is referring to the biological success of ...

Recombinant herpes simplex virus type 1 expressing murine interleukin-4 is less virulent than wild-type virus in mice.

The effect of interleukin-4 (IL-4) on herpes simplex virus type 1 (HSV-1) infection in mice was evaluated by construction of a recombinant HSV-1 expressing the gene for murine IL-4 in place of the latency-associated transcript (LAT). The mutant virus (HSV-IL-4) expressed high levels of IL-4 in cultured cells. The replication of HSV-IL-4 in tissue culture and in trigeminal ganglia was similar to...

Characterization of a Highly Virulent Infectious Bursal Disease Virus