Tema 3 Organització del genoma en virus

Viroids lack genes and capsids, and are single-stranded, circular RNA molecules.

Viroids replicate through a rolling-circle mechanism within their host.

Satellite RNAs are transported in the capsid of helper viruses from cell to cell.

Two main families of viroids are recognized: Pospiviroidae and Avsunviroidae.

Viroids interfere with the production and expression of cellular RNAs in the host.

Satellite RNAs are considered parasites of helper viruses, and can be circular or linear.

Secondary structures formed by viroids protect them from nucleases.

Viroids lack a lipid envelope and associated proteins.

Satellite RNAs act as agents of replication that are independent from the host virus.

Single-stranded RNA of negative sense is one type of viral genome classification.

Viral genome integration into host DNA is one replication mechanism.

Some viruses interfere with host RNA by inducing synthesis of specific viral proteins that inhibit host RNA function.

Bacteriophages can have circular or linear, single- or double-stranded genomes.

A bacteriophage with a complex structure has a head and tail.

Hepadnaviruses have circular DNA genomes with gaps.

Type VI in Baltimore classification represents single-stranded positive-sense RNA with DNA intermediates

Eukaryotic viruses can have filamentous or icosahedral capsids.

Poliovirus replicates by encoding a self-processing polyprotein.

The Vpg protein is crucial for RNA replication during Poliovirus reproduction.

Retroviruses replicate by integrating their genome into the host's DNA.

HIV-1's genome contains 9 genes, some overlapping.

Long terminal repeats (LTRs) in retroviruses provide operational elements for replication.

Poliovirus RNA is single-stranded, linear, and positive-sense.

Reverse transcriptase converts viral RNA into DNA.

Alternative splicing in HIV-1 facilitates the production of multiple protein isoforms.