Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland.
Department of Lake and River Fisheries, University of Warmia and Mazury, Olsztyn, Poland.
Theriogenology. 2014 Mar 15;81(5):723-32. doi: 10.1016/j.theriogenology.2013.12.006. Epub 2013 Dec 18.
β-N-Acetylglucosaminidase (β-NAGase) is an enzyme found in the sperm acrosome of numerous animal species including fish. Fish spermatozoa differ in their morphology including acrosome or acrosomeless aquasperm in chondrostean (e.g., sturgeon) and teleostean (e.g., rainbow trout). It has been shown that β-NAGase exists with high activity in both eggs and sperm of these species. The present study shows the potency of β-NAGase in fertilization. In rainbow trout, increase in sperm motility parameters (VAP and MOT) were observed in the presence of acetamide, an inhibitor for β-NAGase. In contrast, sperm motility parameters (VCL, VSL, VAP, MOT, and PRG) were reduced on the Siberian sturgeon in the presence of acetamide. The inhibition of the activity of β-NAGase in rainbow trout spermatozoa was led to a reduction in the number of fertilized eggs from 79% to 40%, whereas in sturgeon no change was observed in fertilization. Moreover, inhibition of β-NAGase in both spermatozoa and eggs of trout and sturgeon resulted in significant decrease in fertilization rate from 79% to 1% in rainbow trout and from 84% to 12% in Siberian sturgeon. Our research proves that β-NAGase can play a significant role in the fertilization process in teleosteans.
β-N-乙酰氨基葡萄糖苷酶（β-NAGase）是一种存在于许多动物物种精子顶体中的酶，包括鱼类。鱼类精子在形态上有所不同，包括软骨鱼类（如鲟鱼）和硬骨鱼类（如虹鳟鱼）的顶体或无顶体的aquasperm。已经表明，β-NAGase 在这些物种的卵子和精子中都具有高活性。本研究显示了β-NAGase 在受精中的作用。在虹鳟鱼中，在存在乙酰胺（β-NAGase 的抑制剂）的情况下，精子运动参数（VAP 和 MOT）增加。相比之下，在西伯利亚鲟鱼中，在存在乙酰胺的情况下，精子运动参数（VCL、VSL、VAP、MOT 和 PRG）减少。β-NAGase 在虹鳟鱼精子中的活性抑制导致受精卵数量从 79%减少到 40%，而在鲟鱼中，受精没有变化。此外，抑制虹鳟鱼和鲟鱼的精子和卵子中的β-NAGase 导致受精率从 79%显著下降到 1%（在虹鳟鱼中）和从 84%显著下降到 12%（在西伯利亚鲟鱼中）。我们的研究证明了β-NAGase 在硬骨鱼类的受精过程中可以发挥重要作用。
