It's Thursday, and that means it's Nature day. In an article in the current issue, Zegerman and Diffley tackle the subject of DNA replication by looking at phosphorylation sites in a yeast protein to zoom in on two particular sites that appear to be essential to the replication process. In another paper, Saeij et al. present findings on how the protozoon Toxoplasma gondii infects host cells. Using genetic crosses of Toxoplasma strains, the researchers found that gene expression changes significantly and in this article they implicate a protein kinase injected into host cells as the source of pathogenicity. In an editorial, the Nature team once again confronts the issue of scientific misconduct. This time, editors remind readers that the kind of fraud that has been revealed lately is still quite rare. Still, according to the editorial, "the scientific community should continue to concentrate on developing an environment that is inherently consistent with minimizing scientific misconduct." One part of this is "a respectable level of ethics training for all postgraduate students." Read the full column here.