Abstract:

In order to study the mechanism of epidermis regeneration in A. japonicus, and the origination of epidermal cells.The expressions of identification markers of stem cells, the β1 integin, α6 integin and keratin 19(ck19), were studied in the natural and regenerate body wall of sea cucumber through Immunofluorescence method. Results showed that ck19 expression was positive both in the control group and the experimental group. At 1 day of wounding, the cells which expressed ck19 moved towards the edges of the wound surface, and the number of these kinds of cells were similar to those in the control group. At 3 days of wounding, the number of cells positively expressed ck19 decreased significantly compared with those in control. At day 5, the number of the positive cells showed the peak value, and then reduced at 7 days of wounding. The numbers of cells which expressed ck19 showed a kind of increasing at 11 and 13 days compared with those at 7 days. And at day 19, the positive cells were disperse, and the number of them showed no significant differences with those in control.β1 integin and α6 integin were not expressed both in wounding and control body wall of sea cucumber. These data, which combined with the results of histochemical, suggested that the cells labeled with ck19 were the epidermal stem cells and the short-term expanded cells, and they involved in the regeneration of epidermis of body wall. The mechanism of epidermis regeneration in A. japonicus is the Epimorphosis.