Identification of Kctd15 target genes in Xenopus animal caps injected with wnt3a and chordin

We aimed to identify genes that are inhibited by Kctd15 overexpression during neural crest (NC) induction. Injection of RNAs encoding Wnt3a and chordin into the embryo followed by animal cap explant culture leads to the induction of NC marker genes as well as additional genes expressed in the neural plate border. Our previous study indicated that co-injection of kctd15 inhibits the induction of these markers. We injected four sets of RNAs, lacZ as control (L), wnt3a+chd (WC), wnt3a+chd+kctd15 (WCK), and kctd15 (K). After evaluation of marker gene expression with RT-PCR, we prepared probes with same RNA extract for Affymetrix DNA microarray. The hybridization, washing and scanning were perfomed following the manual from Affymetrix. Partek Genomics Suite was employed for data analysis. Xenopus embryos were injected with mRNAs at two-cell stage. When developing to stage 9, the animal caps were dissected for RNA extraction and hybridization on Affymetrix microarrays. According to the mRNAs injected, the animal caps (AC) were divided into four groups, including (1) AC injected with lacZ; (2) AC injected with kctd15; (3) AC injected with chordin and wnt3a; (4) AC injected with chordin, wnt3a and kctd15. The injected animal caps were cultured till stage 15 and then collected for RT-PCR and microarray assay. Each group had three repeats.