Gene expression differences between high and low exploratory genetically identical mice

Genetically identical inbred mice exhibit substantial stable individual variability in exploratory behavior. We used microarrays to look at gene expression differences in the hippocampus in female mice separated by stable differences in exploratory behavior Balb c/J offspring were briefly separated from mothers for 15 minutes each morning on postnatal days 1-14 (handled group) or left undisturbed. At 8 weeks of age mice were tested in the open-field and light-dark behavioral paradigms to verify a handling-induced behavioral phenotype. 2 weeks after behavioral testing, animals were sacrificed and the CA1 region was microdissected. CA1 regions were stored at -20C in RNA later. RNA was extracted from 8 samples (4 handled and 4 non-handled) using Trizol. RNA was extracted from second group of animals (7 handled and 10 non-handled) using Qiagen RNA/DNA columns. All total RNA samples were double round amplied and labeled using standard Affymetrix protocols and hybridized to Mouse 430_2.0 arrays in parallel.