Densoviruses: A Highly Diverse Group of Arthropod Parvoviruses
Max Bergoin and Peter Tijssen
from: Insect Virology (Edited by: Sassan Asgari and Karyn N. Johnson). Caister Academic Press, U.K. (2010)
Densoviruses (DNVs) are defined as small (25 nm), nonenveloped viruses with an icosahedral symmetry containing an unsegmented single-stranded linear DNA genome, 4-6 kb in length, which terminates in short duplex hairpin telomeres involved in DNA replication. According to these properties, DNVs are bona fide members of the Family Parvoviridae, along with vertebrate parvoviruses. The genome of DNVs contains two sets of genes encoding nonstructural (NS) and capsid (VP) proteins. The manner their coding sequences are organized and transcribed as well as the structure of their noncoding 3' and 5' extremities appear very diversified. Some DNVs have a monosense organization i.e. their gene products are encoded in tandem from a single DNA strand. Others have an ambisense organization, i.e. their NS and VP coding sequences are located in the 5' half on both complementary strands. Most DNVs cause fatal diseases in their hosts. However, mortality is less common for shrimp DNVs. Owing to their specificity and high virulence, they have been considered for the biological control of some major insect pests. The ability of recombinant DNV genomes to integrate into host cell DNA has been exploited for stable transformation of insect cells allowing constitutive expression of foreign genes and somatic transformation of insects read more ...