Evolution of vertebrate gill covers via shifts in an ancient Pou3f3 enhancer
Evolution of vertebrate gill covers via shifts in an ancient Pou3f3 enhancer
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DOI：
10.1073/pnas.2011531117
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发表时间：
2020-10-06
影响因子：
11.1
通讯作者：
Crump, J. Gage
中科院分区：
文献类型：
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作者：
Barske, Lindsey;Fabian, Peter;Crump, J. Gage
无颌脊椎动物的鳃腔直接通向环境，而有颌脊椎动物进化出了骨骼附属物，可以将含氧水单向地输送到鳃上。两种有颌脊椎动物谱系之间的一个主要解剖差异是硬骨鱼中存在单个大的鳃盖，而软骨鱼中每个鳃室都有单独的盖。在这里，我们发现这些不同的模式与Pou3f3同源基因的咽弓表达相关。我们发现了一种高度保守的Pou 3f3弓增强子，它通过鲨鱼存在于人类体内，但在无颚鱼中检测不到。骨和软骨鱼增强子之间的微小差异解释了它们的限制性与泛弓表达模式。在斑马鱼中，突变的Pou3f3或保守的增强子破坏鳃盖形成，而异位泛拱Pou3f3b表达产生异位骨骼元件类似的软骨鱼类的多聚体覆盖。出现这种Pou3f3拱增强>430 Mya和随后的修改，因此可能有助于收购和多样化的鳃盖和呼吸策略在颚口进化。斑马鱼dlx2a，这是无颚的
Whereas the gill chambers of jawless vertebrates open directly into the environment, jawed vertebrates evolved skeletal append-ages that drive oxygenated water unidirectionally over the gills. A major anatomical difference between the two jawed vertebrate lineages is the presence of a single large gill cover in bony fishes versus separate covers for each gill chamber in cartilaginous fishes. Here, we find that these divergent patterns correlate with the pharyngeal arch expression of Pou3f3 orthologs. We identify a deeply conserved Pou3f3 arch enhancer present in humans through sharks but undetectable in jawless fish. Minor differences between the bony and cartilaginous fish enhancers account for their restricted versus pan-arch expression patterns. In zebrafish, mutation of Pou3f3 or the conserved enhancer disrupts gill cover formation, whereas ectopic pan-arch Pou3f3b expression generates ectopic skeletal elements resembling the multimeric covers of cartilaginous fishes. Emergence of this Pou3f3 arch enhancer >430 Mya and subsequent modifications may thus have contributed to the acquisition and diversification of gill covers and respiratory strategies during gnathostome evolution. well zebrafish dlx2a, This the jawless