The caligid ectoparasite, Caligus rogercresseyi, is one of the main concerns in the Chilean salmon industry. The molecular mechanisms displayed by the parasite during the reproductive process represent an opportunity for developing novel control strategies. Vitellogenin is a multifunctional protein recognized as a critical player in several crustaceans’ biological processes, including reproduction, embryonic development, and immune response. This study aimed to characterize the C. rogercresseyi vitellogenins, including discovering novel transcripts and regulatory mechanisms associated with microRNAs. Herein, vitellogenin genes were identified by homology analysis using the reference sea louse genome, transcriptome database, and arthropods vitellogenin-protein database. The validation of expression transcripts was conducted by RNA nanopore sequencing technology. Moreover, fusion gene profiling, miRNA target analysis, and functional validation were performed using luciferase assay. Six putative vitellogenin genes were identified in the C. rogercresseyi genome with high homology with other copepods vitellogenins. Furthermore, miR-996 showed a putative role in regulating the Cr_Vitellogenin1 gene, which is highly expressed in females. Moreover, vitellogenin-fusion genes were identified in adult stages and highly regulated in males, demonstrating sex-related expression patterns. In females, the identified fusion genes merged with several non-vitellogenin genes involved in biological processes of ribosome assembly, BMP signaling pathway, and biosynthetic processes. This study reports the genome array of vitellogenins in C. rogercresseyi for the first time, revealing the putative role of fusion genes and miRNA regulation in sea lice biology.

Caligid 体外寄生虫Caligus rogercresseyi是智利鲑鱼产业的主要问题之一。寄生虫在繁殖过程中表现出的分子机制为开发新的控制策略提供了机会。卵黄蛋白原是一种多功能蛋白质，被认为在多种甲壳类动物的生物过程中发挥着关键作用，包括繁殖、胚胎发育和免疫反应。本研究旨在表征C. rogercresseyi卵黄原蛋白，包括发现与 microRNA 相关的新转录本和调控机制。在此，使用参考海虱基因组、转录组数据库和节肢动物卵黄蛋白原蛋白数据库通过同源性分析鉴定卵黄蛋白原基因。通过RNA纳米孔测序技术对表达转录本进行验证。此外，使用荧光素酶测定进行融合基因分析、miRNA 靶点分析和功能验证。在C. rogercresseyi基因组中鉴定出 6 个推定的卵黄原基因，与其他桡足类卵黄原蛋白具有高度同源性。此外，miR-996 在调节Cr_Vitellogenin1基因中显示出假定的作用，该基因在女性中高度表达。此外，卵黄蛋白原融合基因在成年阶段被鉴定出来，并在男性中受到高度调控，证明了与性别相关的表达模式。在雌性中，鉴定出的融合基因与参与核糖体组装、BMP 信号通路和生物合成过程的生物过程的几个非卵黄蛋白原基因融合。这项研究报告了C. rogercresseyi 首次揭示了融合基因和 miRNA 调控在海虱生物学中的假定作用。