Haemocyanin is essential for embryonic development and survival in the migratory locust
Haemocyanin is essential for embryonic development and survival in the migratory locust
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血蓝蛋白对于飞蝗的胚胎发育和生存至关重要
DOI：
10.1111/imb.12177
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发表时间：
2015-10-01
影响因子：
2.6
通讯作者：
Kang, L.
中科院分区：
文献类型：
--
作者：
Chen, B.;Ma, R.;Kang, L.
血蓝蛋白通常被认为是节肢动物血淋巴中的含铜氧载体，并且已经在许多昆虫目中发现。然而，它仍然没有解决为什么血蓝蛋白坚持在昆虫，拥有复杂的气管系统的氧气扩散到细胞。在这里，我们确定了血蓝蛋白的飞蝗，由两个不同的亚基，HC 1和HC 2。基因组序列分析表明，Hc 1和Hc 2分别有4个和3个基因拷贝，这可能是通过基因重复，然后由内含子的分歧进化演变。这两个亚基在mRNA和蛋白质水平上表现出丰富的胚胎特异性表达;它们的表达在中期胚胎中达到峰值，在若虫后期和成虫阶段检测不到。与胚胎相比，蛋黄中的血蓝蛋白比例更大。免疫组织化学染色显示，血蓝蛋白在胚胎中主要表达于表皮。Hc 1和Hc 2的敲低导致显著的胚胎发育延迟和异常以及降低的卵孵化率，即孵化卵的比例。这些结果揭示了血蓝蛋白在昆虫胚胎发育和存活中的一个以前未被认识到的基本作用，可能涉及胚胎与环境之间的分子（如O-2）交换。
Haemocyanins are commonly known as copper-containing oxygen carriers within the haemolymph of arthropods, and have been found in many orders of insects. However, it remains unresolved why haemocyanins persist in insects that possess elaborate tracheal systems for oxygen diffusion to cells. Here we identified haemocyanins in the migratory locust Locusta migratoria that consists of two distinct subunits, Hc1 and Hc2. Genomic sequence analysis indicated that Hc1 and Hc2 have four and three gene copies, respectively, which may have evolved via gene duplication followed by divergent evolution of introns. The two subunits exhibit abundant and embryonic-specific expression at the mRNA and protein level; their expression peaks in the mid-term embryo and is not detectable in the late nymphal and adult stages. A larger proportion of the haemocyanins is present in the yolk compared with that in the embryo. Immunostaining shows that haemocyanins in the embryo are mainly expressed in the epidermis. Knockdown of Hc1 and Hc2 results in significant embryonic developmental delay and abnormality as well as reduced egg hatchability, ie the proportion of hatched eggs. These results reveal a previously unappreciated and fundamental role for haemocyanins in embryonic development and survival in insects, probably involving the exchange of molecules (eg O-2) between the embryo and its environment.