Reduced meiotic crossovers and delayed prophase I progression in AtMLH3-deficient Arabidopsis.

ABSTRACT: Characterization of AtMLH3, the Arabidopsis homologue of the prokaryotic MutL mismatch repair gene, reveals that it is expressed in reproductive tissue where it is required for normal levels of meiotic crossovers (COs). Immunocytological studies in an Atmlh3 mutant indicate that chromosome pairing and synapsis proceed with normal distribution of the early recombination pathway proteins. Localization of the MutS homologue AtMSH4 occurs, suggesting that double Holliday junctions (dHjs) are formed, but the MutL homologue AtMLH1, which forms a heterocomplex with AtMLH3, fails to localize normally. Loss of AtMLH3 results in an approximately 60% reduction in COs and is accompanied by a substantial delay of approximately 25 h in prophase I progression. Analysis of the chiasma distribution in Atml

SUBMITTER: Jackson N 

PROVIDER: S-EPMC1422170 | biostudies-literature | 2006 Mar

REPOSITORIES: biostudies-literature