Keratinized tissues, including whiskers, are ideal for acquiring a record of physiological parameters. Most tissues provide a snapshot of physiological status; however, whiskers may support longitudinal sampling for reproductive and stress-related hormones, if hormones are incorporated as whiskers grow and concentrations change with physiological state. Whiskers from female Steller sea lions (Eumetopias jubatus) and northern fur seals (Callorhinus ursinus) were serially sectioned and pulverized and steroid hormones were extracted. Standard methods were used to validate enzyme immunoassay kits for cortisol, progesterone, 17β-estradiol and testosterone. All hormones were measurable in whisker segments from both species with progesterone concentrations showing cyclical patterns, which appear to signify previous pregnancies or luteal phases. Yearly progesterone concentrations were greater in years a pup was produced compared with years when no pup was observed. Free-ranging female Steller sea lions had reproductive rates between 0 and 1.0 (0.53 ± 0.33, n = 12) using a yearly progesterone concentration of 30 pg/mg or greater to classify a reproductive year as producing a pup and below 30 pg/mg as non-reproductive. Cortisol concentrations were greater near the root and rapidly declined, lacking any obvious patterns, throughout the rest of the whisker. Progesterone and testosterone concentrations were able to help determine sex of unknown individuals. Immunohistochemistry revealed that steroid hormones most likely do not leach out of whiskers based on the deposition patterns of progesterone and cortisol being present throughout the whisker length. Overall, measuring steroid hormones in whiskers can reveal individual reproductive histories over multiple years in sea lions and fur seals. Cyclical patterns of δ¹⁵N were useful for identifying periods of up to ~10 years of growth within whiskers, and measuring both stable isotopes and hormones may be useful for differentiating periods of active gestation from diapause and potentially track multi-year reproductive histories of female otariids.

中文翻译：

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晶须作为一种新的组织，用于追踪北太平洋OTARIID PINnips的生殖激素和压力相关激素

包括晶须在内的角质化组织非常适合获取生理参数记录。大多数组织提供了生理状态的快照。但是，如果随着晶须的生长而加入激素并且浓度随生理状态而变化，则晶须可能支持对生殖激素和压力相关激素的纵向采样。雌性斯特勒海狮（Eumetopias jubatus）和北部海狗（Callorhinus ursinus）的晶须）连续切片并粉碎，并提取类固醇激素。使用标准方法来验证皮质醇，孕酮，17β-雌二醇和睾丸激素的酶免疫测定试剂盒。在这两个物种的晶须片段中，所有激素都是可测量的，孕酮浓度呈周期性变化，这似乎意味着先前的怀孕或黄体期。与未观察到幼崽的年份相比，幼崽产生的年孕激素浓度更高。自由放养的雌性斯特勒海狮的繁殖率在0到1.0之间（0.53±0.33，n = 12）使用30 pg / mg或更高的年孕激素浓度将生殖年归类为产仔，将低于30 pg / mg归为非生殖。在整个晶须的其余部分，皮质醇的浓度在根部附近较高，并迅速下降，没有任何明显的模式。孕酮和睾丸激素的浓度能够帮助确定未知个体的性别。免疫组织化学显示，基于整个晶须长度中存在的孕酮和皮质醇的沉积模式，类固醇激素很可能不会从晶须中浸出。总体而言，测量晶须中的类固醇激素可以揭示海狮和海狗多年的个体生殖史。δ的循环模式¹⁵N可用于识别晶须内至多约10年的生长时期，同时测定稳定的同位素和激素可能有助于区分活跃妊娠与滞育的时期，并可能追踪雌性otariids的多年生殖史。