Division of Life Sciences, Korea Polar Research Institute (KOPRI), Incheon, 21990, Republic of Korea.
Polar Sciences, University of Science and Technology, Incheon, 21990, Republic of Korea.
BMC Genomics. 2024 Nov 18;25(1):1102. doi: 10.1186/s12864-024-11028-0.
The white-blooded Antarctic icefishes is a representative organism that survive under the stenothermal conditions of the Southern Ocean without the hemoglobin genes. To compensate for inefficient oxygen transport, distinct features such as increased heart size, greater blood volume, and reduced hematocrit density enhance the amount of dissolved oxygen and the velocity of blood flow.
Here, we investigated these unique characteristics by comparing high-quality genomic data between white-blooded and red-blooded fishes and identified the loss of FAAP20, which is implicated in anemia. Although the gene region containing FAAP20 is conserved in notothenioids as shown through collinear analysis, only remnants of FAAP20 persist in several icefish species. Additionally, we observed the loss of SOAT1, which plays a pivotal role in cholesterol metabolism, providing a clue for further investigations into the unique mitochondrial form of the icefish.
The loss of FAAP20, which is known to reduce erythrocyte counts under stress conditions in mice and humans, may provide a clue to understanding the genomic characteristics related to oxygen supply, such as low hematocrit, in Antarctic icefishes.
白血南极冰鱼是一种代表生物，它们在南大洋的低温条件下生存，没有血红蛋白基因。为了弥补氧气运输效率低下，增加心脏大小、增加血液量和降低血细胞比容密度等独特特征，提高了溶解氧的含量和血液流动速度。
在这里，我们通过比较白血鱼和红血鱼的高质量基因组数据，研究了这些独特的特征，并确定了 FAAP20 的缺失，这与贫血有关。尽管通过共线性分析表明 FAAP20 基因区域在南极鱼中是保守的，但只有几个冰鱼物种中存在 FAAP20 的残余。此外，我们观察到 SOAT1 的缺失，SOAT1 在胆固醇代谢中起着关键作用，为进一步研究冰鱼独特的线粒体形式提供了线索。
FAAP20 的缺失可能导致在小鼠和人类的应激条件下红细胞计数减少，这为理解与南极冰鱼供氧相关的基因组特征，如低血细胞比容，提供了线索。
