Fig. 2. GeneChips generated from laser-captured cells parallel earlier studies but additionally identify numerous transcription factor mRNAs specifically enriched in ZCs. (A) Dendrogram showing how gene expression profiles generated from laser-capture microdissected cells for the current study cluster with previous profiles of the same cell types. Numbers at branches are modified Pearson's correlations: where 0 means that profiles are identical, 1 means that they are wholly unrelated and 2 means that they are inversely related. Correlations were calculated by comparing the fractional representation of each GO term in each expression profile using GOurmet software (Doherty et al., 2006). LCM, laser-capture microdissected profiles in the current study; Mills et al., ZCs purified by digesting stomachs followed by centrifugation purification (Mills et al., 2003); Mueller et al., data from another previous study (Mueller et al., 2004). (B) Individual GO terms that differentiate each cell population have been selected to show how the types of genes enriched in each expression profile match known functions associated with those cell lineages. Genes described by the GO term `extracellular space' are highly represented in profiles of ZCs with a function of secretion; those described by the term `mitochondrion' are enriched in parietal cells, which are characterized by abundant mitochondria; those described as `actin-binding' are most common in the rapidly migrating, cytoskeleton-fortified pit cells. (C) The same data as in A have been rendered to show the Pearson's correlation between the current ZC profile and all others. Note that the current ZC is most closely related to the previous ZC profile. (D) Heatmap of transcription-regulating genes with expression that is significantly enriched in either the LCM ZC or LCM parietal cell list.