To gain a greater understanding of how early animals generate a regenerative response, we examined the cellular and molecular components involved during wound healing in the anthozoan cnidarian Pharmacological inhibition of extracellular signal-regulated kinases (ERK) signaling blocks regeneration and wound healing in Nematostella.
We characterized early and late wound healing events through genome-wide microarray analysis, quantitative PCR, and hybridization to identify potential wound healing targets.
Immediately after injury, tissue in the aboral portion of the animal became deflated.
This was primarily due to the loss of water within the gastrovascular system, and the inability to stop water-flow from exiting the wound.
Wound healing, a necessary precursor to regeneration.Puncture wounds span both sides of the animal creating two similar wounds.The mitogen-activated protein kinase (MAPK) signaling pathway is present in all eukaryotic genomes and functions in a wide range of cellular processes including immune system regulation, proliferation, apoptosis, cell signaling and movement.Many studies have demonstrated that cnidarians are a powerful model for understanding the evolution of bilaterians, because of their phylogenetic position (sister to bilaterians) and because they are more similar in terms of genomic content and organization to deuterostomes than other model systems [, is widely known as a comparative system for embryological studies, yet following bisection through their major longitudinal axis (the oral-aboral axis) both halves can regenerate into normal animals .Interestingly, regeneration experiments where wound healing was allowed to proceed but cellular proliferation was chemically blocked can be rescued by re-injuring the same untreated tissue, triggering mitosis and regeneration .Overall, the high regenerative capacity and key phylogenetic position of cnidarians provide a unique opportunity to study the basic mechanism underlying animal wound repair.This type of study is of great interest in comparison to other highly regenerative animals (to see similarities) and in comparison to animals that lack the capacity to regenerate (to see differences).(A) Timeline of morphological events during the first six hours after injury.Filamentous actin, a core component of the extracellular matrix and muscle fibers, was labeled with Phallacidin-FL (false-colored black).Overall, scar-free wound healing finished approximately six to eight hours after injury, unless substantial damage to retractor muscles inadvertently occurred during injury.These structures were not repaired at six hours and may need proliferation to regrow [ wound healing.