Ontogenesis of evolved changes in respiratory physiology in deer mice native to high altitude
Ontogenesis of evolved changes in respiratory physiology in deer mice native to high altitude
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DOI：
10.1242/jeb.219360
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发表时间：
2020-03-01
影响因子：
2.8
通讯作者：
Scott, Graham R.
中科院分区：
文献类型：
--
作者：
Ivy, Catherine M.;Greaves, Mary A.;Scott, Graham R.
高海拔环境是寒冷和缺氧的，许多高海拔的本地人已经进化出呼吸生理学的变化，改善了成人缺氧时的O-2吸收。高等哺乳动物在出生后的早期经历了一个剧烈的代谢转变，从外温性到内温性，这可能会影响呼吸性状在高海拔地区的个体发育。我们检查了原产于高海拔地区的鹿鼠（Peromyscus maniculatus）呼吸和血液学特征的发育变化，比较了高地和低地鹿鼠对进行性缺氧的呼吸反应。在成年人中，高地人表现出更高的总通气量和更有效的呼吸模式（相对更深的潮气量），对于在其本土海拔高度捕获和测试的小鼠和在正常氧下实验室饲养的小鼠。还在出生后第7、14、21和30天（P）测试了每个群体的实验室饲养的后代。高地人开发了一个增强的缺氧呼吸反应的P21，同时与颈动脉体的完全成熟，和他们更有效的呼吸模式出现的P14，这些年龄对应的关键基准在高地人的恒温充分发展。然而，高地人表现出发育迟缓，对缺氧，I型细胞在颈动脉体的增生和增加血液血红蛋白含量相比，低地小鼠的过敏性反应。尽管如此，高地人在整个发育过程中在缺氧情况下始终保持较高的动脉氧饱和度，这与从出生起就明显的血液氧亲和力增加有关。我们的结论是，在高海拔鹿小鼠呼吸生理的演变成为表达与产后发展的恒温动物。
High-altitude environments are cold and hypoxic, and many high-altitude natives have evolved changes in respiratory physiology that improve O-2 uptake in hypoxia as adults. Altricial mammals undergo a dramatic metabolic transition from ectothermy to endothermy in early post-natal life, which may influence the ontogenetic development of respiratory traits at high altitude. We examined the developmental changes in respiratory and haematological traits in deer mice (Peromyscus maniculatus) native to high altitude, comparing the respiratory responses to progressive hypoxia between highland and lowland deer mice. Among adults, highlanders exhibited higher total ventilation and a more effective breathing pattern (relatively deeper tidal volumes), for mice that were caught and tested at their native altitudes and those lab-raised in normoxia. Lab-raised progeny of each population were also tested at post-natal day (P)7, 14, 21 and 30. Highlanders developed an enhanced hypoxic ventilatory response by P21, concurrent with the full maturation of the carotid bodies, and their more effective breathing pattern arose by P14; these ages correspond to critical benchmarks in the full development of homeothermy in highlanders. However, highlanders exhibited developmental delays in ventilatory sensitivity to hypoxia, hyperplasia of type I cells in the carotid body and increases in blood haemoglobin content compared with lowland mice. Nevertheless, highlanders maintained consistently higher arterial O-2 saturation in hypoxia across development, in association with increases in blood-O-2 affinity that were apparent from birth. We conclude that evolved changes in respiratory physiology in high-altitude deer mice become expressed in association with the post-natal development of endothermy.