Open AccessDEAD‐box RNA helicases in Arabidopsis thaliana : establishing a link between quantitative expression, gene structure and evolution of a family of genes
Author(s) -
Mingam Annaïck,
ToffanoNioche Claire,
Brunaud Véronique,
Boudet Nathalie,
Kreis Martin,
Lecharny Alain
Publication year - 2004
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/j.1467-7652.2004.00084.x
Subject(s) - biology , genetics , housekeeping gene , gene , genome , dead box , intron , tata box , gene duplication , transcription (linguistics) , computational biology , helicase , promoter , rna , gene expression , linguistics , philosophy
Summary The model genome of Arabidopsis thaliana contains a DEAD‐box RNA helicase family (RH) of 58 members, i.e. almost twice as many as in the animal or yeast genomes. Transcript profiling using real‐time quantitative polymerase chain reaction (PCR) has been obtained for 20 AtRH s from nine different organs. Two AtRH s exhibited plant‐specific profiles associated with photosynthetic and sink organs. The other 18 AtRH s had the same transcript profile, and the levels of transcription of these ‘housekeeping’ AtRH s were under strict quantitative control over a large range of values. Transcript levels may be very different between the most recently duplicated genes. The master regulatory element in the definition of the transcript level is the simultaneous presence of a TATA‐box and an intron in the 5′ untranslated region (UTR). There is a positive and highly significant correlation between the size of the 5′ UTR intron and the transcription level, as long as a characteristic TATA‐box is present. Our work on the housekeeping AtRH s suggests a scenario for the evolution of duplicated genes, leading to both highly and poorly transcribed genes in the same terminal branch of the phylogenetic tree. The general evolutionary drive of the AtRH family, after duplication of a highly transcribed ancestral AtRH, was towards an alteration of the transcriptional activity of the divergent duplicates through successive events of suppression of the TATA‐box and/or the 5′ UTR intron.