Dr. Nir Ohad Department of Plant Sciences, Tel Aviv University, ISRAEL

2009年07月01日(水) 14:00 より 15:00 まで

明大寺地区１階会議室（１１１）

生物進化 長谷部光泰 内線7546

Fertilization in flowering plants initiates the development of the embryo and endosperm, which nurtures the embryo and/or the seedling. Few genes which take part in regulating endosperm development are imprinted, thus expressed in endosperm from their maternal allele, while their paternal allele remains silenced. The mechanisms controlling imprinting of MEDEA (MEA) a member of the SET domain Polycomb group (Pc-G) complex, involves a feedback regulation which ensures maternal control of MEA expression during endosperm development and silencing of both parental alleles during the vegetative phase. This regulation involves the evolutionary conserved PcG complex which acts as a transcription repressing mechanism via association with chromatin and modification of histone tails. PcG complexes epigenetically mark specific sites leading to compaction of chromatin and thereby gene silencing. The evolution of the PcG machinery, as revealed by comparing P.patens as a model system for early terrestrial plants with Arabidopsis representative of flowering plants, and its relation to the parental conflict theory will be discussed.