Gene loss and silencing in Tragopogon miscellus (Asteraceae): comparison of natural and synthetic allotetraploids
Gene loss and silencing in Tragopogon miscellus (Asteraceae): comparison of natural and synthetic allotetraploids
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DOI：
10.1038/hdy.2009.24
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发表时间：
2009-07-01
期刊：
影响因子：
3.8
通讯作者：
Soltis, D. E.
中科院分区：
文献类型：
--
作者：
Buggs, R. J. A.;Doust, A. N.;Soltis, D. E.
全基因组复制（多倍化）是植物中广泛存在的物种形成机制。随着时间的推移，多倍体基因组通过重复基因（同源基因）的缩小和丢失而趋向于更像二倍体的状态，但对于多倍体形成和稳定期间基因丢失的时间知之甚少。一些研究还表明基因转录受到多倍化的影响。在这里，我们检查了异源四倍体 Tragopogon 杂种的 5 个自然群体中 10 组同源物的基因丢失模式，这些群体是在过去 80 年内独立全基因组复制事件后出现的。我们还检查了同一物种的 44 个第一代合成异源多倍体。在第一代异源多倍体中没有出现同源物丢失的情况，但80年后，自然群体中有1.6%的同源物丢失。对于七个同源物组，我们还检查了转录，发现 3.4% 的保留同源物在自然群体中被沉默，但在合成植物中没有。发现的同源基因丢失和沉默事件在自然种群中并不固定，也没有在种群中形成可预测的模式。因此，我们发现同源物的偶然丢失和沉默发生在杂种多倍体形成的几十年内，但不是在最初的一代中。遗传 (2009) 103, 73-81; doi：10.1038/hdy.2009.24； 2009 年 3 月 11 日在线发布
Whole-genome duplication (polyploidisation) is a widespread mechanism of speciation in plants. Over time, polyploid genomes tend towards a more diploid-like state, through downsizing and loss of duplicated genes (homoeologues), but relatively little is known about the timing of gene loss during polyploid formation and stabilisation. Several studies have also shown gene transcription to be affected by polyploidisation. Here, we examine patterns of gene loss in 10 sets of homoeologues in five natural populations of the allotetraploid Tragopogon miscellus that arose within the past 80 years following independent whole-genome duplication events. We also examine 44 first-generation synthetic allopolyploids of the same species. No cases of homoeologue loss arose in the first allopolyploid generation, but after 80 years, 1.6% of homoeologues were lost in natural populations. For seven homoeologue sets we also examined transcription, finding that 3.4% of retained homoeologues had been silenced in the natural populations, but none in the synthetic plants. The homoeologue losses and silencing events found were not fixed within natural populations and did not form a predictable pattern among populations. We therefore show haphazard loss and silencing of homoeologues, occurring within decades of polyploid formation in T. miscellus, but not in the initial generation. Heredity (2009) 103, 73-81; doi: 10.1038/hdy.2009.24; published online 11 March 2009