Abstract：
Gonad maturation is critical for the reproductive success of any organism, and in fish, captivity can significantly affect their reproductive performance, leading to maturation incompetence and spawning failure. The greater amberjack (Seriola dumerili), a fish species recently introduced to aquaculture fails to undergo oocyte maturation, ovulation, and spawning when reared in aquaculture facilities. Since confinement has been shown to influence gonad maturation and completion of the reproductive cycle, investigations into epigenetic mechanisms may shed light on the reasoning behind the reproductive dysfunctions of fish under captivity. Among the known important epigenetic regulators are small non-coding RNAs (sncRNAs), and in particular microRNAs (miRNAs). In this study, immature, maturing (late vitellogenesis), and spent ovaries of captive greater amberjack were collected, and the differential expression of miRNAs in the three different ovarian development stages was examined. Expression patterns of conserved and novel miRNAs were identified, and potential targets of highly differentially expressed miRNAs were detected. Additionally, read length distribution showed two prominent peaks in the three different ovarian maturation stages, corresponding to miRNAs and putative piwi-interacting RNAs (piRNAs), another type of ncRNAs with a germ-cell specific role. Furthermore, miRNA expression patterns and their putative target mRNAs are discussed, in relevance with the different ovarian maturation stages of captive greater amberjack. Overall, this study provides insights into the role of miRNAs in the reproductive dysfunctions observed in fish under captivity and highlights the importance of epigenetic mechanisms in understanding and managing the reproductive performance of economically important fish species.
摘要：
性腺成熟对于任何生物体的生殖成功都至关重要，在鱼中，圈养会显著影响他们的繁殖性能，导致成熟无能和产卵失败。更大的amberjack(Serioladumerili)，最近引入水产养殖的一种鱼类未能经历卵母细胞成熟，排卵,在水产养殖设施中饲养时产卵。由于禁闭已被证明会影响性腺成熟和生殖周期的完成，对表观遗传机制的研究可能会阐明圈养鱼类生殖功能障碍背后的原因。已知的重要表观遗传调节因子是小的非编码RNA（sncRNAs），特别是microRNA(miRNA)。在这项研究中,不成熟,成熟（晚期卵黄发生），并收集了圈养的大Amberjack的废卵巢，并检测了miRNAs在三个不同卵巢发育阶段的差异表达。鉴定了保守的和新的miRNA的表达模式,并检测到高度差异表达的miRNA的潜在靶标。此外,阅读长度分布在三个不同的卵巢成熟阶段显示两个突出的峰，对应于miRNA和推定的piwi相互作用RNA（piRNAs），另一种具有生殖细胞特异性作用的ncRNAs。此外，讨论了miRNA表达模式及其推定的靶mRNA，与圈养大Amberjack的不同卵巢成熟阶段相关。总的来说,这项研究提供了有关miRNA在圈养鱼类生殖功能障碍中的作用的见解，并强调了表观遗传机制在理解和管理经济上重要的鱼类繁殖性能方面的重要性。
