MicroRNA expression profile in Lampetra morii upon Vibrio anguillarum infection and miR-4561 characterization targeting lip

The evolution and functional characterization of transcription factors E2Fs in lamprey, Lethenteron reissneri

The E2 promoter binding factors (E2Fs) are a group of transcriptional regulators that govern the cell cycle and play crucial roles in various cellular physiological processes, including proliferation and embryonic development. In this study, we identified four homologous genes-Lr-E2F3, Lr-E2F4, Lr-E2F5, and Lr-E2F8-from the lamprey (Lethenteron reissneri) genome database. Phylogenetic tree analysis was conducted to elucidate the evolutionary relationships within the E2F family across different species. Furthermore, analyses of motifs, domains, gene structures, and 3D structures reinforced the conservation of the E2F family. Notably, synteny analysis revealed that the neighboring genes of the Lr-E2Fs exhibited greater diversity compared to those in jawed vertebrates. Activity assays indicated that Lr-E2Fs may be involved in lamprey innate immunity mediated by NF-кB. Additionally, morphological observations of embryos microinjected with Cas9/sgRNA demonstrated that E2F-deficient lamprey embryos displayed embryonic lethality, suggesting that Lr-E2Fs play a significant role in lamprey embryonic development. In summary, our research not only provides new insights into the evolution of Lr-E2Fs but also offers valuable clues regarding their functional roles.

Review of the unique and dominant lectin pathway of complement activation in agnathans

As the most primitive vertebrates, lampreys are significant in understanding the early origin and evolution of the vertebrate innate and adaptive immune systems. The complement system is a biological response system with complex and precise regulatory mechanisms and plays an important role in innate and adaptive immunity. It consists of more than 30 distinct components, including intrinsic components, regulatory factors, and complement receptors. Complement system is the humoral backbone of the innate immune defense and complement-like factors have also been found in cyclostomes. Our knowledge as such in lamprey has dramatically increased in the recent years. The searching for complement components in the reissner lamprey Lethenteron reissneri genome database, together with published data, has unveiled the existence of all the orthologues of mammalian complement components identified thus far, including the complement regulatory proteins and complement receptors, in lamprey. This review, summarizes the key themes and recent updates on the complement system of agnathans and discusses the individual complement components of lampreys, and critically compare their functions to that of mammalian complement components. Interestingly, the adaptive immune system of agnathans differs from that of gnathostomes. Lamprey complement components also display some distinctive features, such as lampreys are characterized by the variable lymphocyte receptors (VLRs)-based alternative adaptive immunity. This review may serve as important literature for deducing the evolution of the immune system from invertebrates to vertebrates.

Lamprey immune protein triggers the ferroptosis pathway during zebrafish embryonic development

BACKGROUND

Previously, a novel lamprey immune protein (LIP) was identified, which plays an important role in immunity and the regulation of growth and development in lampreys. However, the mechanism of how LIP regulates growth and development remains unclear.

METHODS

In this study, a zebrafish model of LIP overexpression was established by delivering a transgenic plasmid to the fertilized egg. The biological function of LIP was explored in vivo through phenotypic characterization, comparative transcriptome sequencing, and physiological and biochemical analyses.

RESULTS

LIP caused developmental toxicity in zebrafish, increased embryo mortality and exhibited strong teratogenic, lethal, and developmental inhibitory effects. Comparative transcriptome analysis showed that LIP-induced large-scale cell death by triggering ferroptosis. Furthermore, LIP-induced lipid peroxidation and caused pericardial edema. Direct inhibition of acsl4a and tfr1a, or silencing of acsl4a and tfr1a with specific siRNA suppressed ferroptosis and pericardial edema.

CONCLUSIONS

Taken together, we confirmed that LIP can participate in growth and development via the regulation of lipid peroxidation and ferroptosis. This lays the foundation for future studies on the function of LIP in lampreys. Video Abstract.