Gene expression profiles in normal and Otx2−/− early gastrulating mouse embryos

The mouse Otx2 gene is a homeobox transcription factor required as early as gastrulation for the proper development of the head. We compared gene expression profiles in wild-type and Otx2^-/- 6.5 days postcoitum embryos by using a serial analysis of gene expression assay adapted to microdissected structures. Among a broader list, the study of six genes found to be differentially expressed allows defining a role for Otx2 in the orchestration of cell movements leading to the adequate organization of the embryo before gastrulation.