Gene expression profiling of a mouse model of islet dysmorphogenesis

In the past decade, several transcription factors critical for pancreas development have been identified. Despite this success, many of the cell surface and extracellular factors necessary for proper islet morphogenesis and function remain uncharacterized. Previous studies have shown that transgenic over-expression of the transcription factor HNF6 specifically in the pancreatic endocrine cell lineage resulted in the disruption of islet morphogenesis, including dysfunctional endocrine cell sorting, increased islet size, and failure of islets to migrate away from the ductal epithelium. We exploited the dysmorphic islets in pdx1PBHnf6 animals as a tool to identify factors important for islet morphogenesis. Genome-wide microarray analysis was used to identify differences in the gene expression profiles of late gestation and early postnatal pancreas tissue from wild type and pdx1PBHnf6 animals. We report the identification of genes with an altered expression in HNF6 Tg animals and highlight factors with potential importance in islet morphogenesis. Keywords: disease state analysis, developmental stage analysis Whole genome microarray analysis was used to identify differences in the gene expression profiles of late gestation and early postnatal pancreas tissue from wild type (WT) animals and HNF6 transgenic animals at a time when the events of normal islet morphogenesis are occurring (e18.5 and postnatal day 1). RNA was isolated from individual pancreata at the appropriate developmental stage. Highly pure samples were pooled according to their genotype (3-5 animals per pool) in order to obtain an adequate quantity of RNA for Affymetrix GeneChip analysis. Twelve samples were run in total, 3 replicates each of 4 groups: embryonic day 18.5, wild type mouse; embryonic day 18.5, HNF6 Transgenic mouse; post-natal day 1, wild type mouse; post-natal day 1, HNF6 Transgenic mouse.