DIFFERENTIAL DISPLAY METHODS AND PROTOCOLS

Since the first edition of this book dedicated to differential display (DD) technology was published in 1997, we have witnessed an explosive interest in studying differential gene expression. The gene-hunting euphoria was initially powered by the invention of DD, which was gradually overtaken by DNA microarray technology in recent years. Then why is there still the need for second edition of this DD book? First of all, DD still enjoys a substantial lead over DNA microarrays in the ISI citation data (see Table 1), despite the h- dreds of millions of dollars spent each year on arrays. This may come as a surprise to many, but to us it implies that many of the DNA microarray studies went unpublished owing to their unfulfilled promises (1). Second, unlike DNA microarrays, DD is an “open”-ended gene discovery method that does not depend on prior genome sequence information of the organism being studied. As such, DD is applicable to the study of all living organisms―from bacteria, fungi, insects, fish, plants, to mammals―even when their genomes are not sequenced. Second, DD is more accessible technically and financially to most cost-conscious “cottage-industry” academic laboratories. So clearly DD still has its unique place in the modern molecular biological toolbox for gene expression analysis.

Carrying on the high standards of the first edition of Differential Display Methods, Peng Liang et al. have based their second edition on a new mathematical model of differential display (DD) that takes advantage of automation, as well as digital data acquisition and analysis. These well-versed authors explain and highlight all the recent methodological refinements, including automated liquid handling of hundreds of DD PCR reaction setups combined with capillary electrophoresis, a prototype computer program to automatically allow positive band identification from a fluorescence differential display image, and restriction fragment-based DD screenings that can link any cDNA fragment directly to a given gene once the sequence information of all transcripts becomes available. Other improvements discussed are combining DD and DNA microarrays by reducing the complexity of cDNA probes while increasing the sensitivity of detection, and a DD approach to detect prokaryotic mRNA expression. The authors also demonstrate the power of DD technology with a collection of outstanding examples of DD applications and detailed experimental procedures. The elegant studies described here have led to the discovery of many important genes involved in viral infection, Prion disease, cancer, ovulation, circadian clock, floral color, transcription repression gene silencing, mRNA polymorphism, and protein-RNA interaction.
State-of-the-art and highly practical, Differential Display Methods, Second Edition offers gene hunters the possibility of genome-wide comprehensive DD screening, as well as a proven road map for any successful "gene fishing" expedition.