Silla Aimee J, Roberts J Dale, Byrne Phillip G
School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, Northfields Ave, NSW 2522, Australia.
School of Biological Sciences and Centre for Evolutionary Biology, University of Western Australia, Stirling Highway, Nedlands, WA 6009, Australia.
Conserv Physiol. 2020 Dec 4;8(1):coaa104. doi: 10.1093/conphys/coaa104. eCollection 2020.
Reproductive technologies may assist amphibian conservation breeding programs (CBPs) to achieve propagation targets and genetic management goals. However, a trial-and-error approach to protocol refinement has led to few amphibian CBPs routinely employing reproductive technologies with predictable outcomes. Additionally, while injections can be safely administered to amphibians, perceived animal welfare risks, such as injury and disease transmission, warrant the development of alternative hormone administration protocols. The present study investigated the spermiation response of roseate frogs, , administered various doses of human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone agonist (GnRH-a) via subcutaneous injection. This study also quantified the spermiation response of frogs administered both hormones via topical application. Total sperm, sperm concentration and sperm viability were assessed over a 12-h period post hormone administration. Males released sperm in response to the injection of hCG (88-100% response; 5, 10 or 20 IU), but all samples collected from males administered hCG topically (100, 100 + DMSO or 200 IU hCG) were aspermic. In contrast, males consistently released sperm in response to both the injection (100% response; 1, 5 or 10 μg), or topical application (80-100% response; 50, 50 + DMSO or 100 μg) of GnRH-a. Overall, the administration of GnRH-a was more effective at inducing spermiation than hCG. Mean total sperm and sperm concentration were highest in response to the optimal topically applied dose of 100 μg GnRH-a (mean total sperm = 2.44 × 10, sperm concentration = 1.48 × 10 sperm/ml). We provide novel evidence that topical application provides a viable alternative to injection for the administration of GnRH-a to induce spermiation in amphibians.
生殖技术可能有助于两栖动物保护繁育计划（CBPs）实现繁殖目标和遗传管理目标。然而，对方案进行反复试验的方法导致很少有两栖动物保护繁育计划常规采用能产生可预测结果的生殖技术。此外，虽然可以安全地对两栖动物进行注射，但诸如受伤和疾病传播等被感知到的动物福利风险，促使人们开发替代激素给药方案。本研究调查了通过皮下注射给予不同剂量人绒毛膜促性腺激素（hCG）和促性腺激素释放激素激动剂（GnRH-a）后玫瑰色蛙的排精反应。本研究还对通过局部应用给予两种激素的青蛙的排精反应进行了量化。在激素给药后的12小时内评估总精子数、精子浓度和精子活力。雄性青蛙对注射hCG（88 - 100%有反应；5、10或20国际单位）有排精反应，但从局部给予hCG（100、100 + 二甲基亚砜或200国际单位hCG）的雄性青蛙收集的所有样本均无精子。相比之下，雄性青蛙对注射（100%有反应；1、5或10微克）或局部应用（80 - 100%有反应；50、50 + 二甲基亚砜或100微克）GnRH-a均持续有排精反应。总体而言，给予GnRH-a诱导排精比hCG更有效。对100微克GnRH-a的最佳局部应用剂量反应时，平均总精子数和精子浓度最高（平均总精子数 = 2.44×10，精子浓度 = 1.48×10精子/毫升）。我们提供了新的证据，即局部应用为在两栖动物中给予GnRH-a诱导排精提供了一种可行的注射替代方法。
