Tracking the evolutionary loss of hemoglobin expression by the white-blooded Antarctic icefishes
Tracking the evolutionary loss of hemoglobin expression by the white-blooded Antarctic icefishes
复制标题
DOI：
10.1016/s0378-1119(02)00691-1
复制
发表时间：
2002-08-07
期刊：
影响因子：
3.5
通讯作者：
Detrich, HW
中科院分区：
文献类型：
--
作者：
di Prisco, G;Cocca, E;Detrich, HW
南极冰鱼（南极冰鱼科，南极鱼亚目）的血液中完全没有血红蛋白。冰鱼已经发展出补偿性的适应能力，可以减少对氧气的需求，增强氧气的运输。通过携带物理溶解在等离子体中的气体，氧气输送到组织。为了评估导致冰鱼血红蛋白表型的进化途径，从一个密切相关的，红血的notothenioid物种的成人和胚胎/少年基因复合体分离和表征。Notothenioid成体珠蛋白cDNA的杂交模式表明，三种冰鱼的基因组保留了转录失活的α 1-珠蛋白相关DNA序列，这些序列是红鱼α 1-珠蛋白基因的相同截短变体，包含部分内含子2，全部外显子3和3 '非翻译区。冰鱼的基因组中没有β-珠蛋白基因。此外，Southern印迹的基因组DNA的红，白血（两个物种）的notothenioids，探测与侧翼的胚胎/少年复合体的两端的基因片段，表明冰鱼也失去了胚胎/少年珠蛋白基因。有人提出，不能表达血红蛋白是由一个单一的，大规模的删除事件，删除了所有的冰鱼珠蛋白基因，除了3'端的α 1。(C)出版社：Elsevier Science B. V.
The blood of Antarctic icefishes (family Channichthyidae, suborder Notothenioidei) is completely devoid of hemoglobin. Icefishes have developed compensatory adaptations that reduce oxygen demand and enhance oxygen transport. Oxygen delivery to tissues occurs by carrying the gas physically dissolved in the plasma. To evaluate the evolutionary pathway leading to the icefish hemoglobinless phenotype, the adult and embryonic/juvenile gene complexes from a closely related, red-blooded notothenioid species were isolated and characterized. The hybridization pattern of notothenioid adult globin cDNAs showed that the genomes of three icefish species retain transcriptionally inactive alpha1-globin-related DNA sequences, which are identical truncated variants of the alpha1-globin gene of the red-blooded fish, containing part of intron 2, all of exon 3, and the 3'-untranslated region. The icefish genomes have no beta-globin genes. Furthermore, Southern blots of genomic DNA from red- and white-blooded (two species) notothenioids, probed with fragments of the genes flanking the ends of the embryonic/juvenile complex, indicated that icefishes have also lost embryonic/juvenile globin genes. It is proposed that inability to express hemoglobin arose from a single, large-scale deletional event, which removed all icefish globin genes with the exception of the 3' end of alpha1. (C) 2002 Published by Elsevier Science B.V.