RNA interference (RNAi), which employs double-strand RNA (dsRNA) or small interference RNA (siRNA), is a popular reverse genetic manipulation tool to study gene function. Presently, there is few reports on the implementation of RNAi on the insulin-like androgenic gland gene (IAG) in red swamp crayfish Procambarus clarkii. In this study, the effective sequence of siRNA and optimal injection dose were determined, and the effects of RNAi using dsRNA, siRNA, and long-term RNAi were investigated. The results showed that the doses of 0.5 and 1µg/g of body weight of IAG-siRNA3 produced significantly better inhibition than 0.1µg/g. qPCR assays showed that both dsRNA and siRNA silenced the IAG expression in five tissues (brain, ventral nerve cord, androgenic gland, testis, and vas deferens) in adult P. clarkii, with the effectiveness decreasing over time, inhibiting the production of spermatid. dsRNA exhibited a longer interference effect than siRNA in adults. For long-term interference (P. clarkii juveniles were injected 7 times with 1µg/g of body weight of IAG-dsRNA), and found that the secondary sexual characteristics of juveniles were affected, while the control group developed normally. The results of this study could lay the foundation for crayfish sex reversal with IAG RNAi, and provide the reference for those studies in which the technique of RNAi was used.

中文翻译：

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比较dsRNA和siRNA RNA干扰对红色沼泽小龙虾Procambarus clarkii中胰岛素样雄激素腺基因（IAG）的影响。

RNA干扰（RNAi）使用双链RNA（dsRNA）或小干扰RNA（siRNA），是研究基因功能的一种流行的逆向遗传操作工具。目前，很少有报道在红色沼泽小龙虾Procambarus clarkii中对胰岛素样雄激素基因（IAG）实施RNAi。在这项研究中，确定了siRNA的有效序列和最佳注射剂量，并研究了使用dsRNA，siRNA和长期RNAi的RNAi的作用。结果表明，剂量为0.5和1μg/ g的IAG-siRNA3产生的抑制作用明显优于0.1μg/ g。qPCR分析表明，dsRNA和siRNA均能使成年毕氏疟原虫的5种组织（大脑，腹侧神经索，雄性腺，睾丸和输精管）中的IAG表达沉默，其有效性随时间而降低，抑制精子的产生。在成人中，dsRNA表现出比siRNA更长的干扰作用。为了进行长期干预（向美洲按蚊幼虫注射7次，每次注射1μg/ g的IAG-dsRNA体重），发现少年的继发性特征受到影响，而对照组则正常发育。这项研究的结果可以为IAG RNAi逆转小龙虾的性爱奠定基础，并为那些使用RNAi技术的研究提供参考。对照组正常发育。这项研究的结果可以为IAG RNAi逆转小龙虾的性别奠定基础，并为那些使用RNAi技术的研究提供参考。对照组正常发育。这项研究的结果可以为IAG RNAi逆转小龙虾的性爱奠定基础，并为那些使用RNAi技术的研究提供参考。