Yinglun Han

ECE1 is involved in the development of the lamprey embryonic heart. Endothelin converting enzyme 1 (ECE1) is a key enzyme for the production of endothelin, which, as a potent vasoconstrictor, plays a central role in regulating the growth and differentiation of cardiomyocytes and smooth muscle cells. The enzyme is widely expressed in human tissues and is significantly upregulated in a variety of cancers, with a key impact on the development and invasiveness of cancer. In addition, ECE1 is also involved in the development of neural crest cell-derived organs such as the heart. In vertebrates, jawed animals (such as mammals) mainly express ECE1, ECE1L, and ECE2 genes, but the function of ECE genes in jawless animals (such as the lamprey) has not yet been clarified. In this study, the ECE1 gene was cloned from the Lethenteron reissneri, and bioinformatics analysis showed that it had a high degree of similarity with the ECE1 of jawed vertebrates. This discovery provides important clues for exploring the role of ECE1 in lamprey biology, especially its potential functions in signal transduction, nervous system, cardiovascular system, digestive system, and immune diseases.

The metabotropic glutamate receptor (mGluR, GRM) family is involved in multiple signaling pathways and regulates neurotransmitter release. However, the evolutionary history, distribution, and function of the mGluRs family in lampreys have not been determined. Therefore, we identified the mGluRs gene family in the genome of Lethenteron reissneri, which has been conserved throughout vertebrate evolution. We confirmed that Lr-GRM3, Lr-GRM5, and Lr-GRM7 encode three types of mGluRs in lamprey. Additionally, we investigated the distribution of Lr-GRM3 within this species by qPCR and Western blotting. Furthermore, we conducted RNA sequencing to investigate the molecular function of Lr-GRM3 in lamprey. Our gene expression profile revealed that, similar to that in jawed vertebrates, Lr-GRM3 participates in multiple signal transduction pathways and influences synaptic excitability in lampreys. Moreover, it also affects intestinal motility and the inflammatory response in lampreys. This study not only enhances the understanding of mGluRs’ gene evolution but also highlights the conservation of GRM3’s role in signal transduction while expanding our knowledge of its functions specifically within lampreys. In summary, our experimental findings provide valuable insights for studying both the evolution and functionality of the mGluRs family.

The Pax(paired box) gene family comprises highly conserved transcription factors that play a crucial regulatory role in embryonic development, tissue morphogenesis, and cell differentiation. The gene family comprises of nine members, namely Pax1 to Pax9 , each exhibiting distinct functionalities and expression patterns. Among the members of the Pax family, Pax7 is particularly involved in key regulatory functions related to skeletal muscle development and satellite cell biology in vertebrates. However, the precise role of Pax7 and its downstream targets in jawless vertebrates such as lamprey remains relatively understudied. Therefore, investigating the expression and function of lamprey’s Pax genes holds significant value as a model organism for understanding developmental processes, evolution, and interactions with other vertebrates. In this study, we identified Pax7 in Lethentero reissneri and multiple bioinformatics analyses suggested that it may represent the ancestral gene of the Pax7 shared among higher vertebrates. To further elucidate the function and regulatory mechanism of Pax7 , we performed transcriptome sequencing analysis after silencing Lr.Pax7 expression which revealed alterations in metabolic processes along with associated genes( Plcy,Jagged2,Hes,Myod,Frizzled2 ,etc) involved in various immune pathways( Notch, Wnt, IL-17, TNF , etc), myogenesis process, adipocyte formation process consistent with those observed in higher vertebrates. Comparative studies between lamprey and high vertebrates could provide valuable insight into understanding the functional role of Pax7 and its downstream targets across diverse biological process as well as disease states.