Whole body regeneration (WBR) is the ability to regrow an entire body or adult from a small collection of cells. Wound healing is the process that occurs after injury, and which utilises components of the immune system, blood coagulation cascade and the inflammatory pathways to repair the wound. We study these processes using the colonial ascidian, Botrylloides leachii. B. leachii are chordates, they live in colonies that consist of adults, referred to as zooids, that share a common gelatinous matrix or tunic which is embedded with a vascular system. B. leachii have the ability to regenerate from only a few hundred cells, to form a fully functioning zooid within 8 days. Regeneration arises from a small section of blood vessels but it must not contain any adult zooids for the process to occur. Wound healing occurs in B. leachii when injury results in at least one zooid being left on the colony. It is currently unknown, besides the presence or absence of zooids, what triggers regeneration verses wound healing.
We are using RNA-sequencing at 1, 3, 5, and 10 hour times points to determine the genes and pathways unique to wound healing and regeneration. Preliminary data indicates that there are 121 up-regulated genes in 1h WBR in comparison to 1h WH and 228 with increased expression during 1h WH.
Understanding what triggers regeneration and wound healing may give insight as to why certain species have lost the ability to regenerate, along with the triggers of B. leachii WBR.