Neofunctionalization of a Duplicate dachshund Gene Underlies the Evolution of a Novel Leg Segment in Arachnids.
Neofunctionalization of a Duplicate dachshund Gene Underlies the Evolution of a Novel Leg Segment in Arachnids.
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DOI：
10.1093/molbev/msv200
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发表时间：
2016
影响因子：
10.7
通讯作者：
Natascha Turetzek;Matthias Pechmann;Christoph Schomburg;J. Schneider;Nikola-Michael Prpic
中科院分区：
文献类型：
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作者：
Natascha Turetzek;Matthias Pechmann;Christoph Schomburg;J. Schneider;Nikola-Michael Prpic
新功能的获得或新功能化可以保护重复的基因免于冗余和随后的丢失，并且是驱动适应性进化的主要力量。新功能化已被推断为许多重复基因的基础上，在父母的基因和它的副本之间的调节差异。然而，只有很少的研究实际上将重复基因的新功能与生物体的新形态或生理特征联系起来。在这里，我们表明，腊肠犬（腊肠犬）在蛛形纲动物（蜘蛛和盟友）的复制与一个新的腿节，髌骨的进化。我们已经研究了两个远亲蜘蛛物种，entelegyne蜘蛛Parasteatoda tepidariorum和haplogyne蜘蛛Pholcus phalangioides中的p53基因。这两个物种都拥有两个旁系同源的基因，在恩氏蛛和单雌蛛分裂之前复制。相反，在进化上高度保守的dac1，其重复dac2强烈表达在髌骨腿段在两个物种的胚胎发生过程中。利用亲本RNA干扰P.tepidariorum，我们发现dac2是髌骨段发育所必需的。如果dac2功能受损，则将髌骨与胫骨融合成单个腿部节段。因此，去除dac2的功能，实验性地将P.tepidariorum腿形态恢复到复制髌骨和髌骨段进化之前的阶段。我们的研究结果表明，髌骨的起源是重复和随后的neofunctionalization的蜘蛛类动物血统的结果。
The acquisition of a novel function, or neofunctionalization, protects duplicated genes from redundancy and subsequent loss, and is a major force that drives adaptive evolution. Neofunctionalization has been inferred for many duplicated genes based on differences in regulation between the parental gene and its duplicate. However, only few studies actually link the new function of a duplicated gene to a novel morphological or physiological character of the organism. Here we show that the duplication of dachshund (dac) in arachnids (spiders and allies) is linked with the evolution of a novel leg segment, the patella. We have studied dac genes in two distantly related spider species, the entelegyne spider Parasteatoda tepidariorum and the haplogyne spider Pholcus phalangioides. Both species possess two paralogous dac genes that duplicated before the split between entelegyne and haplogyne spiders. In contrast to the evolutionarily highly conserved dac1, its duplicate dac2 is strongly expressed in the patella leg segment during embryogenesis in both species. Using parental RNA interference in P. tepidariorum we show that dac2 is required for the development of the patella segment. If dac2 function is impaired, then the patella is fused with the tibia into a single leg segment. Thus, removing the function of dac2 experimentally reverts P. tepidariorum leg morphology into a stage before the duplication of dac and the evolution of the patella segment. Our results indicate that the origin of the patella is the result of the duplication and subsequent neofunctionalization of dac in the arachnid lineage.