Genomic changes in synthetic Arabidopsis polyploids
Genomic changes in synthetic Arabidopsis polyploids
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DOI：
10.1111/j.1365-313x.2004.02297.x
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发表时间：
2005-01-01
期刊：
影响因子：
7.2
通讯作者：
Comai, L
中科院分区：
文献类型：
--
作者：
Madlung, A;Tyagi, AP;Comai, L
多倍体是常见的，经常通过基因组复制（同源多倍体）或种间杂交（异源多倍体）产生。新异源多倍体显示不育性、致死性、表型不稳定性、基因沉默和表观遗传变化。关于这些现象的分子基础，以及在异源多倍体化后发生了多少基因组重塑，我们知之甚少。广泛的基因组重塑已被记录在小麦，但很少重塑发生在棉花。新合成的拟南芥异源多倍体，表现出表型不稳定性和低生育力，显示了几个，可能相关的机制，可以重塑基因组。我们检测到几个转座子的转录活性，虽然他们的转座是有限的。一个代表了一个新的家庭的条件活性的恩-Spm-样转座子的拟南芥，这经历了重塑CG甲基化异源多倍体化。一项随机扩增片段长度多态性调查表明，在一些特定的位点重塑。减数分裂分析显示，在相当大一部分花药减数分裂细胞的染色体片段的外观。在人工合成的异源多倍体和天然异源多倍体之间的杂交产生的几个个体中，花粉活力与减数分裂不稳定性呈负相关。选择的DNA转座子的活性和可能相关的染色体断裂可以通过诱导易位和重排引起变化。
Polyploids are common and arise frequently by genome duplication (autopolyploids) or interspecific hybridization (allopolyploids). Neoallopolyploids display sterility, lethality, phenotypic instability, gene silencing and epigenetic changes. Little is known about the molecular basis of these phenomena, and how much genomic remodeling happens upon allopolyploidization. Extensive genomic remodeling has been documented in wheat, but little remodeling occurs in cotton. Newly synthesized Arabidopsis allopolyploids, which display phenotypic instability and low fertility, displayed several, possibly related mechanisms that can remodel genomes. We detected transcriptional activity of several transposons although their transposition was limited. One represents a new family of conditionally active En-Spm-like transposons of Arabidopsis thaliana, which underwent remodeling of CG methylation upon allopolyploidization. A random amplified fragment length polymorphism survey suggested remodeling at few, specific loci. Meiotic analyses revealed the appearance of chromosomal fragments in a substantial fraction of anther meiocytes. In several individuals produced by hybrids between the synthetic and a natural allopolyploid pollen viability inversely correlated with meiotic instability. Activity of selected DNA transposons and the possibly related chromosomal breaks could cause changes by inducing translocations and rearrangements.