A genome is the complete set of genetic information under discussion. For a cellular organism it is encoded in DNA, including genes and other sequences. Specify whether a comparison concerns a nuclear genome, a mitochondrion's genome or all cellular genetic material: the cell nucleus does not contain every DNA sequence in a typical eukaryote. See NHGRI: genome.
Mechanisms limiting the propagation or harmful effects of parasitic genetic material. Shared defence functions do not by themselves prove one origin for all molecular pathways.[ref]
DNA-guided DNA interference by a prokaryotic Argonaute by Daan C. Swarts and others. 2014, Figures 1–4, DNA guides and foreign-DNA restriction
A genetic element maintained separately from host chromosomes in an episomal state. Copying, nuclear retention and partition between daughter biological cells are separate requirements for stable maintenance.
Possession of more than two complete chromosome sets. DNA content can increase without a corresponding increase in cell number.
genome reduction is evolutionary loss of genomic material and functions. Host complementation can relax selection on some pathways, while transmission bottlenecks and genetic drift can also permit deleterious losses; reduction is not necessarily wholly adaptive.
Loss of a function favoured because the costs of retaining it exceed its benefits in a specified environment. This hypothesis differs from neutral deterioration under relaxed selection and requires evidence beyond absence of the gene.
The genome carried within a chloroplast. It retains some photosynthesis and expression-machinery genes, while many components required for its expression are encoded in the nuclear genome.
A representation of genomic variation across multiple sampled individuals or lineages. It can include sequence absent from a single reference, helping address reference-dependent ascertainment.
A mitochondrial genome is the genetic material carried in a mitochondrion. In comparing sampled mitochondrial genomes, the age of their ancestral split is the relevant branch-time calibration; it need not equal the time of separation of the species carrying them.
Locating genetic markers or other features within a genome. Physical positions use DNA sequence distances, while linkage maps use genetic recombination frequencies.
