A unified phylogeny-based nomenclature for histone variants
Epigenetics Chromatin May 31, 2012
May 31, 2012
The lack of a consistent naming convention for histone variants has led to much confusion for histone researchers in recent years, at a time when genome sequencing has become routine and the number of known variants has greatly increased. This has led to problems concerning the similarity of names and incorrect attributions of orthology or common function. Faced with this challenge, attendees of the EMBO Workshop on Histone Variants held last year have developed consistent but flexible naming rules that are both informative and database-searchable. The comprehensive review, published in BioMed Central’s open access journal Epigenetics & Chromatin, proposes a new, unified, phylogeny-based nomenclature for histone variants.
The project, led by Paul Talbert and Steven Henikoff of the Howard Hughes Medical Institute in Seattle, was the result of a community effort of researchers from 35 different institutions worldwide, including Drs. Stefan Dimitrov, Saadi Khochbin and Maria-Elena Torres-Padilla. in response to an urgent need to rationalise the currently inconsistent schemes for naming histone variants.
Histones are proteins that package DNA into structures called nucleosomes found in eukaryote nuclei. They are found in multigene families and may encode isoforms, commonly referred to as histone variants, with different functions. Though the existence of histone variants has been known since the beginnings of histone research, the diversity of their various roles and functions are still being discovered.
Building on current usage, Talbert et al. propose a nomenclature that uses a consistent system of punctuation that reflects phylogenetic relationships among variant subtypes, making explicit the evolutionary links that have been previously unclear. They also recommend using organism-specific numbering, and separate letter suffixes for structurally distinct groups of variants.
This powerfully effective scheme, based on the understanding that common structures and functions reflect shared evolutionary history, should serve to accommodate the ever-increasing rate of discoveries emerging from new genome sequencing projects in the future.