Haploid plants produced by centromere-mediated genome elimination
Haploid plants produced by centromere-mediated genome elimination
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DOI：
10.1038/nature08842
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发表时间：
2010-03-25
期刊：
影响因子：
64.8
通讯作者：
Chan, Simon W. L.
中科院分区：
文献类型：
--
作者：
Ravi, Maruthachalam;Chan, Simon W. L.
产生仅从一个亲本遗传染色体的单倍体植物可以大大加速植物育种（1-3）。从杂合个体产生并转化为二倍体的单倍体产生即时纯合系，绕过近交世代。通常使用两种方法来产生单倍体。首先，培养的配子体细胞可以再生为单倍体植物（4），但许多物种和基因型都不适合这一过程（2，5）。其次，可以从罕见的种间杂交中诱导单倍体，其中一个亲本基因组在受精后被消除（6-11）。基因组消除的分子基础尚不清楚，但有一种理论认为，来自两个亲本物种的着丝粒与有丝分裂纺锤体的相互作用不相等，导致选择性染色体丢失（12-14）。在这里，我们表明，单倍体拟南芥植物可以很容易地产生通过操纵一个单一的着丝粒蛋白，着丝粒特异性组蛋白CENH 3（称为CENP-A在人类）的种子。当表达改变的CENH 3蛋白的cenh 3无效突变体与野生型杂交时，来自突变体的染色体被消除，产生单倍体后代。单倍体通过减数分裂非减数分裂自发转化为可育二倍体，使其基因型得以延续。母本和父本单倍体可以通过正反交产生。我们还利用着丝粒介导的基因组消除将天然的四倍体拟南芥转化为二倍体，降低其倍性以简化育种。由于CENH 3在真核生物中是通用的，我们的方法可以扩展到在任何植物物种中产生单倍体。
Production of haploid plants that inherit chromosomes from only one parent can greatly accelerate plant breeding(1-3). Haploids generated from a heterozygous individual and converted to diploid create instant homozygous lines, bypassing generations of inbreeding. Two methods are generally used to produce haploids. First, cultured gametophyte cells may be regenerated into haploid plants(4), but many species and genotypes are recalcitrant to this process(2,5). Second, haploids can be induced from rare interspecific crosses, in which one parental genome is eliminated after fertilization(6-11). The molecular basis for genome elimination is not understood, but one theory posits that centromeres from the two parent species interact unequally with the mitotic spindle, causing selective chromosome loss(12-14). Here we show that haploid Arabidopsis thaliana plants can be easily generated through seeds by manipulating a single centromere protein, the centromere-specific histone CENH3 (called CENP-A in human). When cenh3 null mutants expressing altered CENH3 proteins are crossed to wild type, chromosomes from the mutant are eliminated, producing haploid progeny. Haploids are spontaneously converted into fertile diploids through meiotic non-reduction, allowing their genotype to be perpetuated. Maternal and paternal haploids can be generated through reciprocal crosses. We have also exploited centromere-mediated genome elimination to convert a natural tetraploid Arabidopsis into a diploid, reducing its ploidy to simplify breeding. As CENH3 is universal in eukaryotes, our method may be extended to produce haploids in any plant species.