RRC ID 4637
Author Sakuma S, Pourkheirandish M, Matsumoto T, Koba T, Komatsuda T.
Title Duplication of a well-conserved homeodomain-leucine zipper transcription factor gene in barley generates a copy with more specific functions.
Journal Funct Integr Genomics
Abstract Three spikelets are formed at each rachis node of the cultivated barley (Hordeum vulgare ssp. vulgare) spike. In two-rowed barley, the central one is fertile and the two lateral ones are sterile, whereas in the six-rowed type, all three are fertile. This characteristic is determined by the allelic constitution at the six-rowed spike 1 (vrs1) locus on the long arm of chromosome 2H, with the recessive allele (vrs1) being responsible for the six-rowed phenotype. The Vrs1 (HvHox1) gene encodes a homeodomain-leucine zipper (HD-Zip) transcription factor. Here, we show that the Vrs1 gene evolved in the Poaceae via a duplication, with a second copy of the gene, HvHox2, present on the short arm of chromosome 2H. Micro-collinearity and polypeptide sequences were both well conserved between HvHox2 and its Poaceae orthologs, but Vrs1 is unique to the barley tribe. The Vrs1 gene product lacks a motif which is conserved among the HvHox2 orthologs. A phylogenetic analysis demonstrated that Vrs1 and HvHox2 must have diverged after the separation of Brachypodium distachyon from the Pooideae and suggests that Vrs1 arose following the duplication of HvHox2, and acquired its new function during the evolution of the barley tribe. HvHox2 was expressed in all organs examined but Vrs1 was predominantly expressed in immature inflorescence.
Volume 10(1)
Pages 123-33
Published 2010-3-1
DOI 10.1007/s10142-009-0134-y
PMID 19707806
PMC PMC2834773
MeSH Amino Acid Sequence Chromosome Mapping Conserved Sequence* Gene Dosage / genetics* Gene Duplication* Gene Expression Regulation, Plant Genes, Plant / genetics Homeodomain Proteins / genetics* Hordeum / genetics* Leucine Zippers / genetics* Molecular Sequence Data Phylogeny Plant Proteins / chemistry Plant Proteins / genetics Plant Proteins / metabolism Reverse Transcriptase Polymerase Chain Reaction Sequence Homology, Amino Acid Transcription Factors / genetics*
IF 3.058
Times Cited 30
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