Poster: Late and Moved Abstracts
Abs #
1017: The Arabidopsis MALE MEIOCYTE DEATH1 gene encodes a PHD-finger protein that is required for male meiosis
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Presenter: |
Yang, Xiaohui , xiaohuiy@yahoo.com |
Authors | Yang, Xiaohui (A) Christopher A., Makaroff (A) | | Affiliations: |
(A): Dept.of Chemistry and Biochemistry, Miami University, Oxford, OH
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Proper formation and development of microspore mother cells is an essential aspect in plant reproduction. The mutation of MMD1 causes alterations in chromatin condensation,chromosome segregation and extensive fragmentation of chromosomes beginning around diakinesis. The mmd1 meiocytes exhibit many characteristics of Programmed Cell Death (PCD), including fragmentation of chromosomes and cytoplasmic shrinkage. FISH analyses identified alterations in centromere and rDNA chromatin condensation/structure and chromosome behavior during meiotic interphase/leptotene and diakinesis respectively. Therefore, although most MMD1 protein is observed at pachytene, the protein is also required very early in meiosis. Molecular analysis of MMD1 indicates that it contains a PHD protein that is similar to MS1 of Arabidopsis, which is thought to be required for chromatin remodelling/transcription in tapetal cells. It is not similar to any previously characterized proteins in other organisms. Many PHD domain containing proteins, including Polycomb-like and Trithorax group genes, are believed to be transcription factors or to be involved in protein-protein, protein-DNA, or protein-RNA interactions associated with chromatin remodelling complexes. Based on the phenotype of mmd1 plants and the presence of PHD domain, MMD1 may function in controlling meiotic gene expression through chromatin-remodelling/packaging. To date MMD1 appears to be unique in that the mmd1 mutation triggers meiotic cell death, which is normally not associated with plant meiotic mutants. At this point it is not clear how/why the mmd1 mutation triggers cell death. Experiments are underway to investigate this question and further understand the role of MMD1 in meiosis.
