RT Journal Article SR Electronic T1 Suppression of the immune response potentiates tadpole tail regeneration during the refractory period JF Development JO Development FD The Company of Biologists Limited SP 2323 OP 2327 DO 10.1242/dev.033985 VO 136 IS 14 A1 Fukazawa, Taro A1 Naora, Yuko A1 Kunieda, Takekazu A1 Kubo, Takeo YR 2009 UL http://dev.biologists.org/content/136/14/2323.abstract AB Regenerative ability varies depending on animal species and developmental stage, but the factors that determine this variability remain unclear. Although Xenopus laevis tadpole tails possess high regenerative ability, this is transiently lost during the `refractory period'. Here, we show that tail amputation evokes different immune responses in wound tail stumps between the `refractory' and `regeneration' periods: there was delayed or prolonged expression of some immune-related genes in the refractory period, whereas there was no obvious or transient expression of other immune-related genes in the regeneration periods. In addition, immune suppression induced by either immunosuppressant treatment or immune cell depletion by knockdown of PU.1 significantly restored regenerative ability during the refractory period. These findings indicate that immune responses have a crucial role in determining regenerative ability in Xenopus tadpole tails.