Gene expression profiling of squirrel monkey brain

A.M. Karssen; S. Her; A.F. Schatzberg; D.M.
Society for Neuroscience 34th Annual Meeting. 2004.


As part of ongoing studies examining the effects of chronic social stress on squirrel monkey brain, we have collected brains of socially stressed monkeys and their controls to characterize gene expression changes using microarrays. Since squirrel monkey microarrays are not available, here we test the feasibility of application of human microarrays on squirrel monkey brain tissue. We performed a species comparison using the Affymetrix human U133A 2.0 array on hippocampal brain tissue of squirrel monkey, macaque monkey, and rat. We chose hippocampal tissue because this region is homologous between species. Affymetrix arrays have previously been shown to be applicable to Macaque monkey brain. Preliminary data analysis showed that there were seven times more genes detected on arrays of monkey brain than on those of rat brain. This corroborates the hypothesis that genomic differences between species reduce the number of suitable probe sets for interspecies comparisons. Cluster analysis of the genes detected on all arrays showed that gene expression patterns in both monkey species were more alike than gene expression patterns in rat. Moreover, the squirrel monkey samples clustered together separately from those of macaque monkey. Of the genes detected on all arrays, seventeen percent were hybridized at higher levels in monkey than in rat. This most likely reflects the lack of perfect-matching probe sets. However, thirteen percent were hybridized at higher levels in rat than in monkey, and these may represent genes that are truly differentially expressed. This interspecies comparison demonstrates that human microarray can be applied on squirrel monkey brain tissue to characterize changes in gene expression after chronic social stress. Support Contributed By: the Pritzker Neuropsychiatric Disorders Research Consortium which is supported by the Pritzker Family Philanthropic Fund. A shared intellectual property agreement exists between the Pritzker Family Philanthropic Fund and all the universities involved.