月日月日MitochondriaandPlastids.ppt

Development of chloroplasts Chlamydomas DNA结合蛋白可抑制线粒体DNA的下调 Mode of Cytoplasmic Inheritance in 295 Angiosperms Why maternal and why biparental? r Digestion of sperm mitochondria in the zygote. Ubiquitination of male mitochondria: Ubiquitinated prohibitin as a proteolytic marker From Thompson et al. 2003 Conclusion It is not the smallness of sperm cell that determines maternal inheritance; The relative inputs of sperm and egg mtDNA are critical for mitochondrial inheritance; An ubiquitin-mediated degeneration of sperm mitochondria is suggested to act as a trigger for maternal inheritance. Non-Mendelian genetics no genes no mutants In plants, the first step is to understand how organelle inheritance is regulated at the cellular level. Degradation of male mtDNA for maternal inheritance Isolation of gametic cells for single-cell PCR to determine the copy number of mtDNA Target Sequences: maturase coxI Competitive PCR sensitive competitive A PCR test using Arabidopsis mesophyll chloroplasts Mitochondrial DNA is not amplified in the egg cells of A. thaliana, A. majus and N. tabacum. The sperm cells of A. thaliana, A. majus and N. tabacum contain less than 1 copy of mtDNA. Whereas the cells of C. melo and P. zonale contain more than 200 copies. Male determines! Mesophyll cell: 670 mt; 61.7 mtDNA 0.092 copies / mt (1/11) Egg cell: 759 mt; 59.0 mtDNA 0.078 copies / mt (1/13) Sperm cell: 9 and 15 mt; 0.083 mtDNA degradation Similarity between egg and somatic cells Insufficiency of mitochondrial genomes Conclusion The egg cell of angiosperm maintains mtDNA equivalent in amount to a somatic cell; Mitochondrial inheritance seems to be determined by unilateral regulations of sperm mtDNA. 0.47 copies Down-regulation when how ? 基础知识 花粉发育及精细胞线粒体DNA上下调 非孟德尔遗传现象发现与1909年。实验表明被子植物精细胞线粒体DNA 的上下调是调控线粒体遗传方式的决定性因素。 A 30-fold down-regulation of mtDNA (482.7/16.0) occurs in the pollens of A. majus. An early generative cell of A. majus may cont