Loss of function of MULTICOPY SUPPRESSOR OF IRA 1 produces nonviable parthenogenetic embryos in Arabidopsis
Loss of function of MULTICOPY SUPPRESSOR OF IRA 1 produces nonviable parthenogenetic embryos in Arabidopsis
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DOI：
10.1016/j.cub.2005.02.066
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发表时间：
2005-04-26
期刊：
影响因子：
9.2
通讯作者：
Berger, F
中科院分区：
文献类型：
--
作者：
Guitton, AE;Berger, F
在有性繁殖的物种中，受精使雌性和雄性配子的基因组在受精卵中结合。在一些动物物种中，雌性配子能够在没有受精的情况下启动胚胎发生，这一过程被称为孤雌生殖。在表观遗传控制下，通过篡改基因座的表达，在小鼠中实现了单性生殖。在植物中，有报道称，在没有受精的情况下，胚胎发育绕过减数分裂导致无细胞分裂发育，而由减少的卵细胞发育成孤雌生殖只在罕见的偶然情况下报道[10]。我们报道了IRA 1的多拷贝抑制基因（MSI1）的单个突变能够启动拟南芥由减数分裂产生的卵细胞的孤雌生殖胚胎发育。WD40重复蛋白MSI1是进化上保守的Polycomb group （PcG）染色质重塑复合物[3]的一部分，与果蝇的视网膜母细胞瘤结合蛋白P55和哺乳动物的RbAp48同源。不可存活的单倍体孤雌生殖msi1胚胎表达的分子标记和极性与受精产生的二倍体野生型（wt）胚胎相似，表明母体对拟南芥胚胎的早期模式有贡献。
In sexually reproducing species, fertilization brings together in the zygote the genomes of the female and male gametes. In several animal species, female gametes are able to initiate embryogenesis in the absence of fertilization, a process referred to as parthenogenesis. Parthenogenesis has been engineered in mice by tampering with expression of loci under epigenetic controls [1]. In plants, embryo development in the absence of fertilization has been reported in cases in which meiosis is bypassed leading to apomictic development, and parthenogenetic development from a reduced egg cell has been only reported in rare accidental cases [2]. We report that single mutations in the gene MULTICOPY SUPPRESSOR OF IRA 1 (MSI1) are able to initiate parthenogenetic development of the embryo in Arabidopsis thaliana from eggs cells produced by meiosis. The WD40 repeat protein MSI1 is part of the evolutionarily conserved Polycomb group (PcG) chromatin-remodeling complexes [3] and is homologous to the Retinoblastoma binding proteins P55 in Drosophila and RbAp48 in mammals [4]. Nonviable haploid parthenogenetic msi1 embryos express molecular markers and polarity similar to diploid wild-type (wt) embryos produced by fertilization, indicating a maternal contribution to early patterning of the Arabidopsis embryo.