Steve Ekker has published a new paper describing a particular set of phenotypic alterations in zebrafish embryos that results from knocking down a range of different genes. These phenotypic alterations are caused by apoptosis mediated by p53. Knocking down p53 simultaneous with another targeted gene knockdown can eliminate the apoptotic phenotype and reveal the specific phenotype related to that other targeted knockdown. This has great potential for eliminating artifacts when using embryonic knockdown techniques.

Robu ME, Larson JD, Nasevicius A, Beiraghi S, Brenner C, Farber SA, Ekker SC. p53 activation by knockdown technologies. PLoS Genetics 2007; in press.
http://genetics.plosjournals.org/perlserv/?request=get-document&doi=10.1371%2Fjournal.pgen.0030078.eor