Description
4 microarray time series was generated to identify cyclic genes of the segmentation clock in the mouse (2 time series), the chicken and the zebrafish. The right posterior half presomitic mesoderms (PSM) from 20 mouse embryos, 18 chicken embryos and 21 zebrafish embryos were dissected while the contralateral side of the embryo containing the left PSM was immediately fixed to be analyzed by in situ hybridization using a Lfng (fot mosue and chicken) or hes7 (zebrafish) probe to order the samples along the segmentation clock oscillation cycle. Probes were produced from RNA extracted from each of the dissected posterior half PSMs using a two-step amplification protocol and were hybridized to Affymetrix GeneChip MOE430A, MOE430 2.0, Affymetrix GeneChip chicken genome array, or Affymetrix GeneChip zebrafish array.