Richard Justin T, Schultz Krystle, Goertz Caroline E C, Hobbs Roderick C, Romano Tracy A, Sartini Becky L
Department of Fisheries, Animal and Veterinary Science, University of Rhode Island, 9 E Alumni Drive, Kingston, RI 02881, USA.
Alaska SeaLife Center, 301 Railway Avenue, Seward, AK 99664, USA.
Conserv Physiol. 2022 Jul 3;10(1):coac045. doi: 10.1093/conphys/coac045. eCollection 2022.
Evaluating respiratory health is important in the management of cetaceans, which are vulnerable to respiratory diseases. Quantifying the expression of genes related to immune function within the respiratory tract could be a valuable tool for directly assessing respiratory health. Blow (exhale) samples allow DNA analysis, and we hypothesized that RNA could also be isolated from blow samples for gene expression studies of immune function. We evaluated the potential to extract RNA from beluga blow samples and tested whether transcripts associated with immune function could be detected with endpoint polymerase chain reaction. A total of 54 blow samples were collected from clinically healthy aquarium belugas ( = 3), and 15 were collected from wild belugas temporarily restrained for health assessment in Bristol Bay, Alaska ( = 9). Although RNA yield varied widely (range, 0-265.2 ng; mean = 85.8; SD = 71.3), measurable RNA was extracted from 97% of the samples. Extracted RNA was assessed in 1-6 PCR reactions targeting housekeeping genes (, or ) or genes associated with immune function (α, or ). Fifty of the aquarium samples (93%) amplified at least one transcript; overall PCR success for housekeeping genes (96/110, 87%) and genes associated with immune function (90/104, 87%) were similarly high. Both RNA yield and overall PCR success (27%) were lower for wild beluga samples, which is most likely due to the reduced forcefulness of the exhale when compared with trained or free-swimming belugas. Overall, the high detection rate with PCR suggests measuring gene expression in blow samples could provide diagnostic information about immune responses within the respiratory tract. While further study is required to determine if quantitative gene expression data from blow samples is associated with disease states, the non-invasive nature of this approach may prove valuable for belugas, which face increasing anthropogenic disturbances.
评估鲸类动物的呼吸健康对于其管理至关重要，因为它们易患呼吸道疾病。量化呼吸道内与免疫功能相关基因的表达可能是直接评估呼吸健康的一个有价值的工具。呼气样本可用于DNA分析，我们推测也可以从呼气样本中分离RNA用于免疫功能的基因表达研究。我们评估了从白鲸呼气样本中提取RNA的潜力，并测试了是否可以通过终点聚合酶链反应检测到与免疫功能相关的转录本。总共从临床健康的水族馆白鲸（n = 3）中收集了54个呼气样本，从阿拉斯加布里斯托尔湾暂时被限制以进行健康评估的野生白鲸（n = 9）中收集了15个呼气样本。尽管RNA产量差异很大（范围为0 - 265.2 ng；平均值 = 85.8；标准差 = 71.3），但97%的样本中提取到了可测量的RNA。提取的RNA在针对管家基因（甘油醛-3-磷酸脱氢酶、β-肌动蛋白或18S核糖体RNA）或与免疫功能相关的基因（α-防御素、β-防御素或白细胞介素-1β）的1 - 6次PCR反应中进行评估。50个水族馆样本（93%）扩增出了至少一种转录本；管家基因（96/110，87%）和与免疫功能相关的基因（90/104，87%）的总体PCR成功率同样很高。野生白鲸样本的RNA产量和总体PCR成功率（27%）都较低，这很可能是因为与经过训练或自由游动的白鲸相比，其呼气力度较小。总体而言，PCR的高检测率表明测量呼气样本中的基因表达可以提供有关呼吸道内免疫反应的诊断信息。虽然需要进一步研究来确定呼气样本中的定量基因表达数据是否与疾病状态相关，但这种非侵入性方法的性质可能对白鲸很有价值，因为白鲸面临着日益增加的人为干扰。
