Ringed (Pusa hispida) and bearded seals (Erignathus barbatus) inhabit vast and often remote areas in the Arctic, making it difficult to obtain long-term physiological information concerning health and reproduction. These seals are experiencing climate-driven changes in their habitat that could result in physiological stress. Chronic physiological stress can lead to immunosuppression, decreased reproduction and decreased growth. Recently, keratin has become a popular matrix to measure steroid hormones, such as stress-related cortisol and reproduction-related progesterone. We developed and validated methods to extract cortisol and progesterone from the claws of adult female ringed (n = 20) and bearded (n = 3) seals using enzyme immunosorbent assays. As ringed and bearded seal claws grow, a pair of dark- and light-colored bands of keratin is deposited annually providing a guide for sampling. Two processing methods were evaluated, removal of claw material with a grinding bit or grinding followed by mechanical pulverization (102 paired samples from six claws, two each from three seals). Adding the mechanical pulverization step resulted in a 1.5-fold increase in hormone extraction. Progesterone from the proximal claw band was evaluated to biologically validate claw material as a measure of pregnancy in ringed seals (n = 14). Claws from pregnant seals had significantly higher claw progesterone concentrations than from non-pregnant seals. This suggests that the elevated progesterone associated with gestation was reflected in the claws, and that the most proximal claw band was indicative of pregnancy status at time of death. Thus, although the sample size was low and the collection dates unbalanced, this study demonstrates the potential to use claws to examine an extended time series (up to 12 yrs) of cortisol and progesterone concentrations in ringed and bearded seal claws.

中文翻译：

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一种新型方法的验证，该方法可从环状和有胡子的海豹的爪中创建激素浓度的时间记录。

圈养（Pusa hispida）和胡须海豹（Erignathus barbatus）居住在北极广大且经常偏远的地区，因此很难获得有关健康和生殖的长期生理信息。这些海豹在其栖息地中受到气候驱动的变化，这可能导致生理压力。慢性生理应激可导致免疫抑制，繁殖减少和生长下降。最近，角蛋白已成为测量类固醇激素的流行基质，例如与压力有关的皮质醇和与生殖有关的孕激素。我们开发并验证了使用酶免疫吸附法从成年雌性环状（n = 20）和胡须（n = 3）海豹的爪中提取皮质醇和孕酮的方法。随着环状和有胡子的海豹爪的成长，每年沉积一对深色和浅色的角蛋白带，为采样提供指南。评估了两种加工方法：用磨头去除爪材料或先研磨，然后进行机械粉碎（六个爪中有102个成对样品，三个密封件各有两个）。添加机械粉碎步骤会导致激素提取增加1.5倍。对来自近端爪带的黄体酮进行了评估，以对爪材料进行生物学验证，以作为环斑海豹中妊娠的量度（n = 14）。怀孕海豹的爪子的孕酮浓度明显高于未怀孕海豹的爪子。这表明与妊娠相关的孕酮升高反映在爪中，并且最接近的爪带指示死亡时的妊娠状态。从而，