A Comprehensive Ultrastructure and Transcriptome Analyses of Early Regeneration in Ophryotrocha Xiamen Sp. Nov. (Annelida: Dorvilleidae)

BackgroundIn recent years, significant progress has been made using powerful genetic approaches with newly developed models for understanding on regeneration, however, the molecular and cellular basis of early regeneration remains unclear. Annelids of the genus Ophryotrocha have long been subjects of research use as model species in ecological, toxicological, reproductive, and regenerative investigations. Although, Ophryotrocha spp., are amenable to molecular, cellular, and functional analyses, still in need to explore new model organisms in this genus to understand regeneration mechanisms. Here, we focus on a newly identified Ophryotrocha species for its early regeneration developmental mode.ResultsBased on detailed morphological (K-maxillae, rosette gland, and chromosome number) and molecular analyses, we present, O. xiamen as a new suitable model species to investigate the early regeneration mechanism. The comparative transcriptome analysis showed the gene expression patterns were related to transcriptional regulation, energy metabolism profiles and structure and signal transduction during early stages of regeneration. Data also exhibited that genes such as neurotrypsin, Nos2, DMBT1, SCO spondin, and endotubin associated to regulate inflammation, enterocyte differentiation, apoptosis, and neuroepithelial, were up-regulated during early regeneration stages (wound healing and blastema formation). Additionally, most of the known regeneration-related genes of annelids were also identified in O. xiamen which enabled to explore the precise functions of genes involved in regeneration process.ConclusionsThis study enriches the identification of genus Ophryotrocha in Chinese coastal zones, an area with high abundances of annelids. The comparative transcriptome analysis provided the whole expression changes during early regeneration process. Morphology and molecular shred of evidences in O. xiamen revealed similar features of early regeneration with other invertebrates. Information on potential candidate genes associated with early regeneration in O. xiamen, will be useful for further studies.