Reactions triggered in response to the presence of a virus that act to protect the cell or organism.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus from a virus.

The resolution of the male germline syncytium or cyst into individual gametes by packaging each spermatid into its own plasma membrane.

The process in which double-stranded RNAs silence cognate genes. Involves posttranscriptional gene inactivation ('silencing') both of transgenes or dsRNA introduced into a germline, and of the host gene(s) homologous to the transgenes or dsRNA. This silencing is triggered by the introduction of transgenes or double-stranded RNA (dsRNA), and can occur through a specific decrease in the level of mRNA, or by negative regulation of translation, of both host genes and transgenes.

Any process that affects the rate, extent or location of chromatin silencing.

Any process that results in the specification, formation or maintenance of the physical structure of eukaryotic heterochromatin and contributes to chromatin silencing.

A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A compact and highly condensed form of chromatin.