Retrotransposons and genomic stability in populations of the young allopolyploid species Spartina anglica CE Hubbard (Poaceae)
Retrotransposons and genomic stability in populations of the young allopolyploid species Spartina anglica CE Hubbard (Poaceae)
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DOI：
10.1093/oxfordjournals.molbev.a004182
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发表时间：
2002-08-01
影响因子：
10.7
通讯作者：
Schulman, AH
中科院分区：
文献类型：
--
作者：
Baumel, A;Ainouche, M;Schulman, AH
19世纪世纪末，在英国由本地的Spartina maritima和引入的Spartina alterniflora杂交而产生Spartina X townsendii。杂交基因组的复制产生了大米草，一个充满活力的异源多倍体参与自然和人工入侵几个大陆。该系统允许调查伴随新的异源多倍体物种稳定的早期进化变化。由于异源多倍性可能是一种基因组休克，引发反转录元件插入活性，我们研究了是否存在于亲本物种的反转录转座子已被激活的基因组中的S。英国国教。为此，我们使用了反转录转座子间扩增多态性（IRAP）和反转录转座子-微卫星扩增多态性（REMAP）标记，它们是基于多位点PCR的方法，用于检测基因组中反转录转座子整合事件。英国国教。群体主要由一个主要的多位点基因型组成，与第一代杂种S相同。唐氏X在年轻的异源多倍体基因组中，很少有新的整合位点。我们还发现，在异源多倍体亲本亚基因组的严格加性。这两个结果表明，S。英国圣公会自成立以来，并没有经历过广泛的变化。这与以前的文献结果形成对比，文献报道了实验再合成的异源多倍体的快速结构变化。
Spartina X townsendii arose during the end of the 19th century in England by hybridization between the indigenous Spartina maritima and the introduced Spartina alterniflora, native to the eastern seaboard of North America. Duplication of the hybrid genome gave rise to Spartina anglica, a vigorous allopolyploid involved in natural and artificial invasions on several continents. This system allows investigation of the early evolutionary changes that accompany stabilization of new allopolyploid species. Because allopolyploidy may be a genomic shock, eliciting retroelement insertional activity, we examined whether retrotransposons present in the parental species have been activated in the genome of S. anglica. For this purpose we used inter-retrotransposon amplified polymorphism (IRAP) and retrotransposons-microsatellite amplified polymorphism (REMAP) markers, which are multilocus PCR-based methods detecting retrotransposon integration events in the genome, IRAP and REMAP allowed the screening of insertional polymorphisms in populations of S. anglica. The populations are composed mainly of one major multilocus genotype, identical to the first-generation hybrid S. X townsendii. Few new integration sites were encountered in the young allopolyploid genome. We also found strict additivity of the parental subgenomes in the allopolyploid. Both these findings indicate that the genome of S. anglica has not undergone extensive changes since its formation. This contrasts with previous results from the literature, which report rapid structural changes in experimentally resynthesized allopolyploids.