Adams David M, Williamson Sean A, Evans Roger G, Reina Richard D
School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria 3800, Australia.
R Soc Open Sci. 2022 Aug 31;9(8):220709. doi: 10.1098/rsos.220709. eCollection 2022 Aug.
Green turtle () embryos are in an arrested state of development when the eggs are laid, but in the presence of oxygen, arrest is broken and development resumes within 12-16 h. However, the precise oxygen level at which embryos break arrest and continue development is not known. To better understand the impact of oxygen concentration on breaking of arrest and early embryonic development, we incubated freshly laid eggs of the green sea turtle for three days at each of six different oxygen concentrations (less than or equal to 1%, 3%, 5%, 7%, 9% and 21%) and monitored the appearance and growth of white spots on the shell, indicative of embryonic development. As reported previously, white spots did not develop on eggs incubated in anoxia (less than or equal to 1% oxygen). For all other treatments, mean time to white spot detection and white spot growth rate varied inversely with oxygen concentration. In nearly all cases the difference between eggs at different oxygen levels was statistically significant ( ≤ 0.05). This suggests that sea turtle embryonic development may respond to oxygen in a dose-dependent manner. Our results indicate that the development of green turtle embryos may be slowed if they are exposed to the most hypoxic conditions reported in mature natural nests.
绿海龟（）胚胎在产卵时处于发育停滞状态，但在有氧气的情况下，停滞状态被打破，发育在12 - 16小时内恢复。然而，胚胎打破停滞并继续发育的确切氧气水平尚不清楚。为了更好地理解氧气浓度对打破停滞和早期胚胎发育的影响，我们将刚产下的绿海龟卵在六种不同氧气浓度（小于或等于1%、3%、5%、7%、9%和21%）下分别孵育三天，并监测龟壳上白点的出现和生长情况，白点表明胚胎在发育。如先前报道，在缺氧（氧气含量小于或等于1%）条件下孵育的卵上没有出现白点。对于所有其他处理，检测到白点的平均时间和白点生长速率与氧气浓度呈反比。几乎在所有情况下，不同氧气水平下的卵之间的差异具有统计学意义（≤0.05）。这表明海龟胚胎发育可能以剂量依赖的方式对氧气作出反应。我们的结果表明，如果绿海龟胚胎暴露在成熟自然巢穴中报道的最缺氧条件下，其发育可能会减缓。
