Weddell seal iron dynamics and oxygen stores across lactation

The profound impacts that maternal provisioning of finite energy resources has on offspring survival have been extensively studied across mammals. However, in addition to calories, we tested whether high hemoprotein concentrations in diving mammals necessitates exceptional female-to-pup iron transfer. To answer this question adult female Weddell seals (Leptonychotes weddellii) were handled across the austral summer. This included post-partum females during lactation and post-weaning. To demonstrate that any observed changes in iron dynamics were due to lactation, equivalent skip-breeding females (i.e., that did not produce a pup) were also handled. We measured numerous indices of iron mobilization (ferritin, serum iron, total-iron-binding-capacity, transferrin saturation, milk iron concentration), hemoprotein concentrations, and oxygen stores.

母体为后代提供有限能量资源对其存活的深远影响，已在各类哺乳动物中得到广泛研究。然而，除热量供给外，我们还针对潜水哺乳动物体内的高血红素蛋白（hemoprotein）浓度是否需要雌性向幼崽进行额外铁元素转运这一科学问题展开了测试。为解答该问题，我们在南半球夏季期间对成年雌性威德尔海豹（Leptonychotes weddellii）进行了采样处理，研究对象涵盖泌乳期的产后雌性个体以及断奶后的雌性个体。为验证所观测到的铁动态变化确实由泌乳行为所致，我们同时对同等条件下的跳过繁殖雌性（即未产下幼崽的个体）进行了采样操作。我们测定了多项铁调运相关指标：铁蛋白（ferritin）、血清铁（serum iron）、总铁结合力（total-iron-binding-capacity）、转铁蛋白饱和度（transferrin saturation）、乳铁浓度（milk iron concentration），以及血红素蛋白浓度与氧储备量。