Reviewer 1's Review (Rob Steele)

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This manuscript presents the first study on p53 homologues in a non-bilaterian animal. As such it makes an important contribution to our understanding of the evolution of a gene which has been the major focus of work in a large number of laboratories. This paper provides the first proof that p53 genes are present in diploblastic animals and it also provides evidence of at least one function for the gene, protection of the germ line from genotoxic damage.
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N.B. These are the general comments made by the reviewer when reviewing this paper in light of which the manuscript was revised. Specific points addressed during revision of the paper are not shown.