Hormonal induction of spermiation, previously reported to be immunogenic in fishes, is a common hatchery practice in pikeperch, Sander lucioperca. The aim of the present study was to investigate the effects of repeated induction of spermiation in pikeperch, following application of either human chorionic gonadotropin (hCG) or salmon gonadoliberine analogue (sGnRHa) on sperm quality indices as well as on immune and stress response. Mature males of pikeperch (n = 7 per group) were stimulated twice with five days between injections of either hCG (hCG; 500 IU kg-1), sGnRHa (sGnRHa; 50 μg kg-1) or NaCl (control group; 1 ml kg-1) to assess spermatozoa motility with a computer-assisted sperm analysis (CASA) system. During second sampling, blood plasma was sampled for humoral innate immune (peroxidase and lysozyme activities, ACH50), stress (cortisol, glucose) and endocrine (testosterone) markers. In addition, the head kidney was dissected to assay the expression of several immune genes (such as il1, c3, hamp, tnf-α and lys genes). The results indicate that hormonal treatment significantly increased sperm production. Sperm sampled after the hormonal treatment maintained its quality throughout the study, regardless of the sampling time. However, it appears that the application of hCG induced elevated cortisol and glucose plasma levels compared to the control group. Almost all immune markers, except the relative expression of hepcidin (hamp gene), were unaffected by the two hormones applied. The results showed that the induction treatment of spermiation processes in pikeperch resulted in an important physiological stress response for which the intensity varied according to the hormonal agent used. However, this stress response (more profound following application of hCG) was weakly associated with innate immune functions. On the other hand, a significant negative correlation between the expression of several important immune markers (peroxidase activity, relative expression of c3 and il1 genes) and sperm quality indices indicates significant involvement of immune status on sperm quality. The results obtained shed light on immune-system-induced modifications to sperm quality. The data presented here highlight the need for careful revision of broodstock management and selection practices where welfare status as well as individual predispositions of fish to cope with the stress should be taken under the consideration.

中文翻译：

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重复的激素对精子的诱导影响应激，但不影响鲈鱼的免疫反应（Sander lucioperca）。

以前曾报道鱼类在鱼类中具有免疫原性，这是荷尔蒙对精子的诱导，是梭子鱼Sander lucioperca常见的孵化场。本研究的目的是研究人绒毛膜促性腺激素（hCG）或鲑鱼性腺多巴胺类似物（sGnRHa）对精子质量指标以及免疫和应激反应的影响，从而反复诱导精子中的精子形成。在两次注射hCG（hCG; 500 IU kg-1），sGnRHa（sGnRHa; 50μgkg-1）或NaCl（对照组; 1 ml）之间间隔五天刺激两次鲈鱼的成熟雄性（每组n = 7）。 kg-1），以计算机辅助的精子分析（CASA）系统评估精子活动能力。在第二次采样中，对血浆进行了体液先天免疫（过氧化物酶和溶菌酶活性，ACH50），应激（皮质醇，葡萄糖）和内分泌（睾丸激素）标记。另外，解剖头部肾脏以测定几种免疫基因（例如il1，c3，hamp，tnf-α和lys基因）的表达。结果表明，激素治疗显着增加了精子的产生。荷尔蒙治疗后采样的精子在整个研究过程中保持其质量，而与采样时间无关。但是，与对照组相比，hCG的使用似乎诱导了皮质醇和葡萄糖血浆水平的升高。除了hepcidin（hamp基因）的相对表达外，几乎所有的免疫标记都不受所用两种激素的影响。结果表明，诱导处理梭子鱼的精子化过程产生了重要的生理应激反应，其强度随所用激素的不同而变化。但是，这种应激反应（在应用hCG之后更为深刻）与先天免疫功能弱相关。另一方面，几种重要的免疫标志物的表达（过氧化物酶活性，c3和il1基因的相对表达）与精子质量指标之间呈显着负相关，表明免疫状态与精子质量显着相关。获得的结果揭示了免疫系统对精子质量的修饰。