|Nei, Masatoshi - PENN STATE UNIV, PA|
Submitted to: Annual Review of Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2005
Publication Date: June 22, 2005
Citation: Nei, M., Rooney, A.P. 2005. Concerted and birth-and-death evolution of multigene families. Annual Review of Genetics. 22(15):121-152. Interpretive Summary: Gene families are defined as groups of functionally related genes. Because they form a large component of the genome, it is important to understand aspects of gene family structure and organization if we are to fully understand genome structure and organization. This paper is a review article that covers the processes and mechanisms that shape gene family structure and organization. In addition, we explain how gene family research will ultimately reveal how organisms acquire highly complex genetic systems such as the immune system. This review provides important information for researchers studying genome structure, function and evolution.
Technical Abstract: Until around 1990, most multigene families were thought to be subject to concerted evolution, in which all member genes of a family evolve as a unit in concert. However, phylogenetic analysis of MHC and other immune systems genes showed quite a different evolutionary pattern, and a new model called birth-and-death evolution was proposed. In this model new genes are created by gene duplication and some duplicate genes stay in the genome for a long time whereas others are inactivated or deleted from the genome. Later investigations have shown that most non-rRNA genes including highly conserved histone or ubiquitin genes are subject to this type of evolution. However, the controversy over the two models is still continuing because the distinction between the models becomes difficult when sequence differences are small. Unlike concerted evolution, the model of birth-and-death evolution can give some insights into the origins of new genetic systems or new phenotypic characters.