Evolution of Hemoglobin Genes in a Subterranean Rodent Species (Lasiopodomys mandarinus)

Splice Variant of Spalax Heparanase Skipping Exon 12

The subterranean blind mole rat, Spalax, has evolved significantly over 47 million years to thrive in its underground habitat. A key enzyme in this adaptation is heparanase, which degrades heparan sulfate (HS) in the extracellular matrix (ECM), facilitating angiogenesis and releasing growth factors for endothelial cells. Spalax heparanase has various splice variants influencing tumor growth and metastasis differently. We report a novel splice variant from a hypoxia-exposed kidney sample resulting from exon 12 skipping. This variant maintains the translation frame but lacks enzymatic activity, offering insights into Spalax's unique adaptations.

The hypoxia adaptation of small mammals to plateau and underground burrow conditions

Oxygen is one of the important substances for the survival of most life systems on the earth, and plateau and underground burrow systems are two typical hypoxic environments. Small mammals living in hypoxic environments have evolved different adaptation strategies, which include increased oxygen delivery, metabolic regulation of physiological responses and other physiological responses that change tissue oxygen utilization. Multi-omics predictions have also shown that these animals have evolved different adaptations to extreme environments. In particular, vascular endothelial growth factor (VEGF) and erythropoietin (EPO), which have specific functions in the control of O2 delivery, have evolved adaptively in small mammals in hypoxic environments. Naked mole-rats and blind mole-rats are typical hypoxic model animals as they have some resistance to cancer. This review primarily summarizes the main living environment of hypoxia tolerant small mammals, as well as the changes of phenotype, physiochemical characteristics and gene expression mode of their long-term living in hypoxia environment.