Subfunctionalization was proposed by Stoltzfus and Force et al. as one of the possible outcomes of functional divergence that occurs after a gene duplication event, in which pairs of genes that originate from duplication, or paralogs, take on separate functions.

What is Neofunctionalization and Subfunctionalization?

Under neofunctionalization, one copy retains its ancestral functions, and the other acquires a novel function (1). Under subfunctionalization, mutations damage different functions of each copy, such that both copies are required to preserve all ancestral gene functions (9, 10).

What causes gene duplication?

Gene duplications can arise as products of several types of errors in DNA replication and repair machinery as well as through fortuitous capture by selfish genetic elements. Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage.