The Arabidopsis MutS homolog AtMSH5 is required for normal meiosis.
MSH5, a member of the MutS homolog DNA mismatch repair protein family, has been shown to be required for proper homologous chromosome recombination in diverse organisms such as mouse, budding yeast and Caenorhabditis elegans. In this paper, we show that a mutant Arabidopsis plant carrying the putative disrupted AtMSH5 gene exhibits defects during meiotic division, producing a proportion of nonviable pollen grains and abnormal embryo sacs, and thereby leading to a decrease in fertility. AtMSH5 expression is confined to meiotic floral buds, which is consistent with a possible role during meiosis. Cytological analysis of male meiosis revealed the presence of numerous univalents from diplotene to metaphase I, which were associated with a great reduction in chiasma frequencies. The average number of residual chiasmata in the mutant is reduced to 2.54 per meiocyte, which accounts for approximately 25% of the amount in the wild type. Here, quantitative cytogenetical analysis reveals that the residual chiasmata in Atmsh5 mutants are randomly distributed among meiocytes, suggesting that AtMSH5 has an essential role during interference-sensitive chiasma formation. Taken together, the evidence indicates that AtMSH5 promotes homologous recombination through facilitating chiasma formation during prophase I in Arabidopsis.
Lu
Xiaoduo
X
School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
Liu
Xiaolin
X
An
Lizhe
L
Zhang
Wei
W
Sun
Jian
J
Pei
Huijuan
H
Meng
Hongyan
H
Fan
Yunliu
Y
Zhang
Chunyi
C
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008540:Meiosis / Q000235:genetics*; D049469:Meiotic Prophase I / Q000235:genetics; D008969:Molecular Sequence Data; D051719:MutS DNA Mismatch-Binding Protein / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D030821:Plants, Genetically Modified; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C530474:MSH5 protein, Arabidopsis; C036483:T-DNA; D051719:MutS DNA Mismatch-Binding Protein