Expression of stem cell pluripotency factors during regeneration in the earthworm Eisenia foetida

• Eisenia foetida full-length sox2 gene and partial oct4, nanog, c-myc and lin28 genes were cloned.
• Expressions of all five cloned genes were up-regulated and tissue specific during regeneration.
• Regeneration of earthworm may involve a process of dedifferentiation and reprogramming.

Stem cell pluripotency factors can induce somatic cells to form induced pluripotent stem cells, which are involved in cell reprogramming and dedifferentiation. The tissue regeneration in the earthworm Eisenia foetida may involve cell dedifferentiation. There is limited information about associations between pluripotency factors and the regeneration. In this report, cDNA sequences of pluripotency factors, oct4, nanog, sox2, c-myc and lin28 genes from the earthworm E. foetida were cloned, and quantitative PCR analysis was performed for their mRNA expressions in the head, clitellum and tail. The maximum up-regulation of oct4, nanog, sox2, c-myc and lin28 occurred at 12 h, 4 days, 12 h, 2 days, and 24 h after amputation for 110, 178, 21, 251 and 325-fold, respectively, in comparison with the controls. The results suggest that the tissues are regenerated via cellular dedifferentiation and reprogramming.