Development of a porcine small intestinal cDNA micro-array: characterization and functional analysis of the response to enterotoxigenic E. coli.

The intestine is a complex and dynamic ecosystem, in which nutrients, exogenous compounds and micro-flora interact, and its condition is influenced by the complex interaction between these factors and host genetic elements. Furthermore, interactions of immune cells with the other components of the intestinal mucosa are essential in the defense against pathogens. The outcomes of these complex interactions determine resistance to infectious diseases. The development of genomic tools and techniques allows for analysis of multiple and complex host responses. We have constructed a porcine small intestinal micro-array, based on cDNA from jejunal mucosal scrapings. Material from two developmental distinct stages (4- and 12-week-old pigs) was used in order to assure a reasonably broad representation of mucosal transcripts. The micro-array consists of 3468 cDNAs spotted in quadruplicate. Comparison of the 4-week-old versus 12-week-old pigs revealed a differential expression in at least 300 spots. Furthermore, we report the early gene expression response of pig small intestine jejunal mucosa to infection with enterotoxigenic E. coli (ETEC) using the small intestinal segment perfusion (SISP) technique. A response pattern was found in which a marker for innate defense dominated, demonstrating the strength of this applied technology. Further analysis of these response patterns will contribute to a better understanding of enteric health and disease in pigs. The great similarity between pig and human suggest results from these continuing studies should be applicable for both agricultural and human biomedical purposes.