China-UK-NYNU-RRes Joint Laboratory of insect biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, Nanyang Normal University, 473061, Nanyang, Henan, China.
School of Life Science, Zhengzhou University, 450001, Zhengzhou, Henan, China.
BMC Genomics. 2021 May 22;22(1):374. doi: 10.1186/s12864-021-07692-1.
20-hydroxyecdysone (20E) plays important roles in insect molting and metamorphosis. 20E-induced autophagy has been detected during the larval-pupal transition in different insects. In Bombyx mori, autophagy is induced by 20E in the larval fat body. Long non-coding RNAs (lncRNAs) function in various biological processes in many organisms, including insects. Many lncRNAs have been reported to be potential for autophagy occurrence in mammals, but it has not been investigated in insects.
RNA libraries from the fat body of B. mori dissected at 2 and 6 h post-injection with 20E were constructed and sequenced, and comprehensive analysis of lncRNAs and mRNAs was performed. A total of 1035 lncRNAs were identified, including 905 lincRNAs and 130 antisense lncRNAs. Compared with mRNAs, lncRNAs had longer transcript length and fewer exons. 132 lncRNAs were found differentially expressed at 2 h post injection, compared with 64 lncRNAs at 6 h post injection. Thirty differentially expressed lncRNAs were common at 2 and 6 h post-injection, and were hypothesized to be associated with the 20E response. Target gene analysis predicted 6493 lncRNA-mRNA cis pairs and 42,797 lncRNA-mRNA trans pairs. The expression profiles of LNC_000560 were highly consistent with its potential target genes, Atg4B, and RNAi of LNC_000560 significantly decreased the expression of LNC_000560 and Atg4B. These results indicated that LNC_000560 was potentially involved in the 20E-induced autophagy of the fat body by regulating Atg4B.
This study provides the genome-wide identification and functional characterization of lncRNAs associated with 20E-induced autophagy in the fat body of B. mori. LNC_000560 and its potential target gene were identified to be related to 20-regulated autophagy in B. mori. These results will be helpful for further studying the regulatory mechanisms of lncRNAs in autophagy and other biological processes in this insect model.
20-羟基蜕皮酮（20E）在昆虫蜕皮和变态过程中发挥着重要作用。在不同昆虫的幼虫-蛹转变过程中，已经检测到 20E 诱导的自噬。在家蚕中，20E 在幼虫脂肪体中诱导自噬。长非编码 RNA（lncRNA）在许多生物的各种生物学过程中发挥作用，包括昆虫。许多 lncRNA 已被报道可能在哺乳动物中发生自噬，但在昆虫中尚未进行研究。
构建并测序了 20E 注射后 2 和 6 小时家蚕脂肪体的 RNA 文库，并进行了 lncRNA 和 mRNA 的综合分析。共鉴定出 1035 个 lncRNA，包括 905 个 lincRNA 和 130 个反义 lncRNA。与 mRNAs 相比，lncRNAs 的转录本长度更长，外显子更少。与 6 小时相比，注射后 2 小时有 132 个 lncRNA 表达差异，注射后 6 小时有 64 个 lncRNA 表达差异。在 2 和 6 小时注射后有 30 个差异表达的 lncRNA 是共同的，这些 lncRNA 被假设与 20E 反应有关。靶基因分析预测了 6493 个 lncRNA-mRNA cis 对和 42797 个 lncRNA-mRNA trans 对。LNC_000560 的表达谱与其潜在靶基因 Atg4B 高度一致，LNC_000560 的 RNAi 显著降低了 LNC_000560 和 Atg4B 的表达。这些结果表明，LNC_000560 通过调节 Atg4B 参与 20E 诱导的脂肪体自噬。
本研究提供了家蚕脂肪体中与 20E 诱导自噬相关的 lncRNA 的全基因组鉴定和功能特征。鉴定了 LNC_000560 及其潜在靶基因与 B. mori 中 20 调节的自噬有关。这些结果将有助于进一步研究 lncRNA 在该昆虫模型自噬和其他生物学过程中的调控机制。
