Phycodnaviridae: Difference between revisions

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==Virion Structure of a Phycodnaviridae==
==Virion Structure of a Phycodnaviridae==


The virions of phycodnaviridae consist of a non-enveloped capsid. The virion attaches to the host cell surface and releases DNA into the host cell in a similar fashion as Tectiviridae. The capsid is round and exhibits polyhedral symmetry. The isometric capsid has a diameter of 130-200 nm. The capsid shells of virions are composed of multiple layers and are referred to as multilaminated capsids. The capsids appear hexagonal in outline.
The virions of phycodnaviridae consist of a non-enveloped capsid. The virion attaches to the host cell surface and releases DNA into the host cell in a similar fashion as Tectiviridae. The capsid is round and exhibits polyhedral symmetry. The isometric capsid has a diameter of 130-200 nm. The capsid shells of virions are composed of multiple layers and are referred to as multilaminated capsids. The capsids appear hexagonal in outline. (source: [http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/index.htm ICTVdB Descriptions])


==Reproduction Cycle of a Phycodnaviridae in a Host Cell==
==Reproduction Cycle of a Phycodnaviridae in a Host Cell==

Revision as of 14:26, 19 June 2006

Baltimore Classification

Higher order taxa

Viruses; dsDNA viruses, no RNA stage; Phycodnaviridae

Genera

Chlororvirus, Coccolithovirus, Phaeovirus, Prasinovirus, Prymnesiovirus

Description and Significance

Phycodnaviridae are viruses with double-stranded DNA that infect chlorella, algal symbionts of paramecia and hydras.

Genome Structure

The genome of phycodnaviridae is not segmented and contains a single molecule of linear double-stranded DNA. The complete genome is 250000-350000 nucleotides long. The genome guanine+cytosine content is 40-52 %. The genome contains unusual bases, varying from 0.1-47 %. These bases are 5-methyl deoxy-cytosine residues and N6-methyl deoxy-adenosine residues in some DNAs. The double-stranded DNA is non-permuted and the genome sequence has termini with cross-linked hairpin ends. The genome, except for the hairpin, has terminally redundant sequences. These sequences have inverted terminal repetitions (ITR) for at least 2000 bases. (source: ICTVdB Descriptions)

Virion Structure of a Phycodnaviridae

The virions of phycodnaviridae consist of a non-enveloped capsid. The virion attaches to the host cell surface and releases DNA into the host cell in a similar fashion as Tectiviridae. The capsid is round and exhibits polyhedral symmetry. The isometric capsid has a diameter of 130-200 nm. The capsid shells of virions are composed of multiple layers and are referred to as multilaminated capsids. The capsids appear hexagonal in outline. (source: ICTVdB Descriptions)

Reproduction Cycle of a Phycodnaviridae in a Host Cell

Viral Ecology & Pathology

References