LAUSR

Nori is the cultivated seaweed with the highest market value in the world. Monospores from the thalli reseed the cultivating nets and provide useful secondary seedlings in nori farming, but the underlying molecular basis remains unclear. To explore crucial genes and pathways related to monospore-producing process in Phycocalida chauhanii ( Pyropia chauhanii ), transcriptomic analysis over the time-course of key developmental stages was carried out. According to comparative analysis, a total of 19,490 differentially expressed genes (DEGs) were identified. Based on time series trend clustering analysis, 7294 DEGs were enriched in a predominant profile 45, in good accordance with the actual temporal monospore-producing processes, exhibiting an expression trend of first upregulated and then downregulated. Gene Ontology (GO) analysis revealed that the function of these DEGs were top three enriched in GO biological processes of positive regulation of GTPase activity, signal transduction, and protein phosphorylation. KEGG pathway analysis indicated that these DEGs were top three enriched in the “mitogen-activated protein kinase (MAPK) signaling pathway, regulation of autophagy, and endocytosis”. Besides, the expression levels of 12 selected DEGs were validated by real-time quantitative PCR and proved the accuracy of RNA-seq results. Collectively, these findings provide a comprehensive landscape of the molecular mechanism underlying the formation and release of monospores, which might serve as essential basis for the identification of key genes that contribute to monospore formation.