Glossary
Glossary
Bias in gene retention
the retention of copies of genes after duplication is not random, relative to gene function or evolutionary rate. This bias can be a confounding factor in large scale analyses of paralogs: the function of duplicate genes in a genome results both from the bias in retention and from evolution after duplication.
Homologs
genes descending from a common ancestor.
In-paralogs
paralogs resulting from a duplication after a speciation event of reference.
Negative selection
selection that decreases the chance of fixation of a mutation because it is detrimental; it results in a decrease in the rate of evolution of selected mutations.
Neofunctionalization
the process in which one paralog gains a new function, which is selectively advantageous.
One-to-one orthologs
orthologs which are present in a single copy in each genome of interest.
Orthologs
homologs which have diverged since a speciation event.
Out-paralogs
paralogs resulting from a duplication before a speciation event of reference.
Paralogs
homologs which have diverged since a duplication event.
Positive selection
selection that increases the chance of fixation of a mutation because it is beneficial; it results in an increase in the rate of evolution of selected mutations.
Subfunctionalization
the process in which paralogs partition the ancestral function, so that each performs only part of this function. Subfunctionalization can happen by degenerating reciprocal mutations (DDC model), or by positive selection for specialization (escape from adaptive conflict).
Trends in Genetics
Volume 25, Issue 5, May 2009, Pages 210-216