%0 Journal Article
%T TaMSH7: A cereal mismatch repair gene that affects fertility in transgenic barley (Hordeum vulgare L.)
%A Andrew H Lloyd
%A Andrew S Milligan
%A Peter Langridge
%A Jason A Able
%J BMC Plant Biology
%D 2007
%I BioMed Central
%R 10.1186/1471-2229-7-67
%X Sequencing of the three MSH7 genes, located on the short arms of wheat chromosomes 3A, 3B and 3D, has revealed no significant sequence divergence at the amino acid level suggesting conservation of function across the homoeogroups. Functional analysis of MSH7 through the use of RNAi loss-of-function transgenics was undertaken in diploid barley (Hordeum vulgare L.). Quantitative real-time PCR revealed several T0 lines with reduced MSH7 expression. Positive segregants from two T1 lines studied in detail showed reduced MSH7 expression when compared to transformed controls and null segregants. Expression of MSH6, another member of the mismatch repair family which is most closely related to the MSH7 gene, was not significantly reduced in these lines. In both T1 lines, reduced seed set in positive segregants was observed.Results presented here indicate, for the first time, a distinct functional role for MSH7 in vivo and show that expression of this gene is necessary for wild-type levels of fertility. These observations suggest that MSH7 has an important function during meiosis and as such remains a candidate for Ph2.In most organisms there are evolutionarily conserved mechanisms in place that minimise the frequency of mismatches introduced during DNA replication [1]. As plants lack a reserved germ-line, mutation occurring in somatic cells can be transmitted to the next generation. Consequently, the need for an effective post-replicative DNA repair mechanism is pronounced. The mismatch repair (MMR) system is an essential component of this DNA repair.In eukaryotes MMR is undertaken by the MutS and MutL homologues (MSH and MLH). Both MSH and MLH polypeptides form MSH and MLH heterodimeric proteins, respectively, which act together to bind mismatched DNA and initiate repair. Most eukaryotes have genes encoding six MSH proteins, however a seventh MSH protein (MSH7) has been identified in plants [2].All MSH proteins, except MSH1, have been shown to act in DNA repair and/or recom
%U http://www.biomedcentral.com/1471-2229/7/67