Hypobaric Hypoxia Causes Low Fecundity in Zebrafish Parents and Impairment of Skeletal Development in Zebrafish Embryos and Rat Offspring

Hypobaric Hypoxia (HH) negatively affects the cardiovascular and respiratory systems as well as gonadal development and the therefore next generation. This study investigated the effects of HH on zebrafish and SD rats, by exposing them to a low-pressure environment at 6,000m elevation for 30 days to simulate high-altitude conditions. It was indicated that parental zebrafish reared amh under HH had increased embryo mortality, reduced hatchability, and abnormal cartilage development in the offspring. Furthermore, the HH-exposed SD rats had fewer reproductive cells and smaller litters. Moreover, the transcriptome analysis revealed the down-regulation of steroid hormone biosynthesis pathways. The expression of the gonad-associated genes (amh, pde8a, man2a2 and lhcgr), as well as the gonad and cartilage-related gene bmpr1a, were also down-regulated. In addition, Western blot analysis validated reduced bmpr1a protein expression in the ovaries of HH-treated rats. In summary, these data indicate the negative impact of HH on reproductive organs and offspring development, emphasizing the need for further research and precautions to protect future generations' health.