Evolution of Respiratory Proteins across the Pancrustacea
Evolution of Respiratory Proteins across the Pancrustacea
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DOI：
10.1093/icb/icv079
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发表时间：
2015-11-01
影响因子：
2.6
通讯作者：
Burmester, Thorsten
中科院分区：
文献类型：
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作者：
Burmester, Thorsten
呼吸蛋白增强血液运输氧气的能力，并支持细胞内氧气的储存和输送。血蓝蛋白和血红蛋白是存在于泛甲壳动物中的呼吸蛋白。含铜的血蓝蛋白是从节肢动物干群谱系中的酚氧化酶进化而来的。长期以来，血蓝蛋白仅在软甲纲甲壳动物中被发现，但最近的研究也在桨足纲、介形纲和鳃尾目中鉴定出了血蓝蛋白。血红蛋白在鳃足纲中很常见，但也偶尔在其他甲壳动物类群（软甲纲、桡足纲、蔓足纲）中被发现。由于气管系统的存在，呼吸蛋白长期以来被认为在六足动物中是不必要的。只有摇蚊、一些仰泳蝽以及马胃蝇是已知的例外，它们都生活在缺氧条件下，并拥有血红蛋白。然而，最近的数据表明血蓝蛋白存在于大多数无变态和半变态昆虫中。系统发育分析显示昆虫和桨足纲的血蓝蛋白相似，这表明这些分类群之间关系密切。血蓝蛋白在蜻蜓目、蜉蝣目和真变态类（半翅目 + 全变态类）中已经缺失。在蟑螂和蝗虫中，血蓝蛋白的表达仅限于发育中的胚胎，而在成虫中，氧气仅由气管系统供应。这种模式表明血蓝蛋白是泛甲壳动物最后共同祖先血淋巴中的氧气运输蛋白。其缺失可能与小型化、氧气供应受限时期、生活方式的改变或形态变化有关。一旦缺失，血蓝蛋白就不会再重新出现。一些泛甲壳动物还拥有功能不确定的细胞珠蛋白基因，这些基因低水平表达。当再次需要呼吸蛋白时，血红蛋白从细胞珠蛋白独立进化了多次。
Respiratory proteins enhance the capacity of the blood for oxygen transport and support intracellular storage and delivery of oxygen. Hemocyanin and hemoglobin are the respiratory proteins that occur in the Pancrustacea. The copper-containing hemocyanins evolved from phenoloxidases in the stem lineage of arthropods. For a long time, hemocyanins had only been known from the malacostracan crustaceans but recent studies identified hemocyanin also in Remipedia, Ostracoda, and Branchiura. Hemoglobins are common in the Branchiopoda but have also been sporadically found in other crustacean classes (Malacostraca, Copepoda, Thecostraca). Respiratory proteins had long been considered unnecessary in the hexapods because of the tracheal system. Only chironomids, some backswimmers, and the horse botfly, which all live under hypoxic conditions, were known exceptions and possess hemoglobins. However, recent data suggest that hemocyanins occur in most ametabolous and hemimetabolous insects. Phylogenetic analysis showed the hemocyanins of insects and Remipedia to be similar, suggesting a close relationship of these taxa. Hemocyanin has been lost in dragonflies, mayflies, and Eumetabola (Hemiptera+Holometabola). In cockroaches and grasshoppers, hemocyanin expression is restricted to the developing embryo while in adults oxygen is supplied solely by the tracheal system. This pattern suggests that hemocyanin was the oxygen-transport protein in the hemolymph of the last common ancestor of the pancrustaceans. The loss was probably associated with miniaturization, a period of restricted availability of oxygen, a change in life-style, or morphological changes. Once lost, hemocyanin was not regained. Some pancrustaceans also possess cellular globin genes with uncertain functions, which are expressed at low levels. When a respiratory protein was again required, hemoglobins evolved several times independently from cellular globins.