Chiang Mai Journal of Science

Ultimately, one wishes to determine how genes and the proteins they encode function in the intact embryo. Today, the exploration of gene function often begins with a DNA microarray. This technique has revolutionized the way in which gene expression is now analyzed by allowing the RNA products of thousands of genes to be monitored at once. Comprehensive studies of gene expression and identifying gene interaction partners also provide an additional layer of information useful for predicting gene function. Other approaches to discover a gene’s function, include searching for homologous genes in other organisms and determining when and where a gene is expressed. Searching for homologous genes and analyzing gene expression patterns can provide clues about gene function, but they do not reveal what exactly a gene does inside a cell. Genetic engineering provides a powerful solution to this problem especially allows one to specifically produce such gene knockouts. Normally, only one of the two DNA strands in is transcribed into RNA, and it is always the same strand for a given gene. If a cloned gene is engineered so that the opposite DNA strand is transcribed instead, it will produce antisense RNA molecules that have a sequence complementary to the normal RNA transcripts. Such antisense RNA can often hybridize with the “sense” RNA and thereby inhibit the synthesis of the corresponding protein. The purpose of this review is to focus on microarray and RNA interference technology as tools to study gene expression in bovine embryos during the preimplantation period.