Department of Biology, University of Maryland, College Park, United States.
Elife. 2022 Jan 5;11:e69109. doi: 10.7554/eLife.69109.
Dark caves lacking primary productivity can expose subterranean animals to hypoxia. We used the surface-dwelling (surface fish) and cave-dwelling (cavefish) morphs of as a model for understanding the mechanisms of hypoxia tolerance in the cave environment. Primitive hematopoiesis, which is restricted to the posterior lateral mesoderm in other teleosts, also occurs in the anterior lateral mesoderm in , potentially pre-adapting surface fish for hypoxic cave colonization. Cavefish have enlarged both hematopoietic domains and develop more erythrocytes than surface fish, which are required for normal development in both morphs. Laboratory-induced hypoxia suppresses growth in surface fish but not in cavefish. Both morphs respond to hypoxia by overexpressing () pathway genes, and some genes are constitutively upregulated in normoxic cavefish to similar levels as in hypoxic surface fish. We conclude that cavefish cope with hypoxia by increasing erythrocyte development and constitutive gene overexpression.
缺乏初级生产力的黑暗洞穴会使地下动物暴露在缺氧环境中。我们使用作为模型，研究了地下环境中缺氧耐受的机制，该模型包括表面栖息（表面鱼）和洞穴栖息（洞穴鱼）两种形态。在其他硬骨鱼中，原始的造血作用仅限于后外侧中胚层，但在中也发生在前外侧中胚层，这可能使表面鱼预先适应了缺氧的洞穴栖息地。洞穴鱼扩大了造血区域，比表面鱼产生更多的红细胞，这对于两种形态的正常发育都是必需的。实验室诱导的缺氧抑制了表面鱼的生长，但对洞穴鱼没有影响。两种形态都通过过度表达 () 途径基因来应对缺氧，并且一些基因在常氧洞穴鱼中被组成性地上调，其水平与缺氧表面鱼相似。我们的结论是，洞穴鱼通过增加红细胞发育和组成性基因过表达来应对缺氧。
