Rapid, Repeated, and Clustered Loss of Duplicate Genes in Allopolyploid Plant Populations of Independent Origin
Rapid, Repeated, and Clustered Loss of Duplicate Genes in Allopolyploid Plant Populations of Independent Origin
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DOI：
10.1016/j.cub.2011.12.027
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发表时间：
2012-02-07
期刊：
影响因子：
9.2
通讯作者：
Barbazuk, W. Brad
中科院分区：
文献类型：
--
作者：
Buggs, Richard J. A.;Chamala, Srikar;Barbazuk, W. Brad
进化的可预测性是有争议的，最近的证据表明，结果可能受到基因相互作用网络的限制[1]。全基因组重复（WGD;多倍体化-在植物进化中普遍存在[2]）提供了评估基因组减少的可预测性的机会，这是进化的普遍特征[3，4]。重复模式的基因组减少似乎已经发生了通过重复的基因（同源）损失在不同的物种后，古老的WGD [5-9]，有证据表明，优先保留重复在某些基因类别[8-10]。这些模式出现的速度尚不清楚。我们检查了来自5个独立起源的自然种群的59株芒叶草植物中70个同源异型基因座的存在/不存在;这种异源四倍体与80年前通过二倍体亲本与WGD之间的杂交产生类似[11]。基因在簇中重复保留或丢失，并且丢失基因的基因本体类别对应于同一家族（菊科;向日葵家族）中在古代WGD之后丢失的那些基因[6]并且具有基因剂量敏感性[8]。这些结果提供了证据表明，WGD的结果是可预测的，即使在40代中，可能是由于基因产物的连接性[8，10，12]。检测到的单等位基因丢失的高频率和群体内固定的变化的低频率为持续的进化提供了证据。
The predictability of evolution is debatable, with recent evidence suggesting that outcomes may be constrained by gene interaction networks [1]. Whole-genome duplication (WGD; polyploidization-ubiquitous in plant evolution [2]) provides the opportunity to evaluate the predictability of genome reduction, a pervasive feature of evolution [3, 4]. Repeated patterns of genome reduction appear to have occurred via duplicated gene (homeolog) loss in divergent species following ancient WGD [5-9], with evidence for preferential retention of duplicates in certain gene classes [8-10]. The speed at which these patterns arise is unknown. We examined presence/absence of 70 homeologous loci in 59 Tragopogon miscellus plants from five natural populations of independent origin; this allotetraploid arose similar to 80 years ago via hybridization between diploid parents and WGD [11]. Genes were repeatedly retained or lost in clusters, and the gene ontology categories of the missing genes correspond to those lost after ancient WGD in the same family (Asteraceae; sunflower family) [6] and with gene dosage sensitivity [8]. These results provide evidence that the outcomes of WGD are predictable, even in 40 generations, perhaps due to the connectivity of gene products [8, 10, 12]. The high frequency of single-allele losses detected and low frequency of changes fixed within populations provide evidence for ongoing evolution.