Trouble with differential display

Differential Display. Edited by Ronald A. Leslie and Harold A. Robertson. Oxford University Press, 2000. US$ 115.00 (hbk) (274 pages) ISBN 0 19 9637598 XDifferential display (DD) is a well-developed method for comparative cDNA expression studies. Its advantages and limitations have been widely discussed both in periodic publications and books. It is interesting to look at how the progress in this widely used technique is reflected in this recent book.This collective work contains 12 chapters. The first is the editorial introduction and subsequent chapters are devoted to various topics including fluorescent DD, cloning of differentially expressed brain cDNAs, DD of memory-associated genes and DD in single-cell organisms. Several chapters also describe new developments that enhance or complement traditional DD. The intention of the editors was to create a comprehensive and balanced picture of different approaches for cDNA expression profiling. Such a book would be of a great help for many researchers at the time when genomic sequence information is accumulating with cosmic speed and acquiring functional data is a much slower process that requires robust and high-throughput techniques.Indeed, several chapters in the book are well written and reach the point. For example, a chapter on the microSAGE (serial analysis of gene expression) technique describes a modification from the original SAGE procedure adapted for gene expression studies in specialized brain regions, where only minimal amounts of starting tissues, and consequently RNAs, are available. The method takes advantage of immobilization of mRNA on the walls of streptavidin-coated microtubes, which allows many steps to be performed as a ‘single-tube’ procedure. As a result, microSAGE allows working with at least 5000-fold less mRNA than in conventional SAGE. This useful chapter is complemented with clear schemes and experimental data. The chapter on DNA microarray preparation is an excellent detailed introduction to this technology – helpful both for the newcomers and more experienced researchers. The chapter on practical aspects of DD is also a solid useful practical guide through the entire DD project, starting from the choice of the objects for comparison and finishing with all the experimental details.However, many blemishes substantially flaw several articles in the book. The chapter ‘Recent advances in fluorescent differential display’ is one example. In an article with ‘Recent advances in…’ in the title, you expect to get a discussion, or at least one reference to the original procedure or a mention of the author who used the reviewed technique for the first time. It is not the case in this chapter. There is not one indication that Bauer et al. and Ito et al. were the first to apply fluorescent recording in DD. In addition, the reference choice in this chapter is strange to say the least. For example, the author uses the 1995 review article by Lisitsyn as a reference for representational difference analysis (RDA) and writes that RDA has been modified for the use with cDNAs in 1994. It seems to me that it would be more appropriate to refer to the original paper on RDA by Lisitsyn et al. 1993 and then to cite the 1994 paper on RDA applied to cDNAs. Additionally, the author describes RDA method and then subtractive display as if these are unrelated methods. The appearance of subtractive hybridization in the chapter devoted to fluorescent DD is odd because it has no relation to the main topic and makes the chapter unfocused.It would be not so upsetting if all the mistakes and imperfections were associated with only one chapter but unfortunately that is not the case. Chapter 5, for example, is called ‘The use of RT-PCR differential display in single-celled organisms and plant tissues’. At the same time, the two last sentences of the Introduction confuse the reader: ‘The application of the differential display in single-celled organisms and fungi has also been reported and will not be reviewed here. The approaches are similar to those presented in this chapter’.Furthermore, the book is full of laboratory slang and grammar mistakes. This book was intended to provide readers with the updated protocols for DD and with information on new developments in the field of comparative expression studies. That is a difficult task in the time when many companies provide corresponding kits with the detailed description of the basics of underlying molecular biology and step-by-step protocols. This makes the editor's job especially challenging, and the success or the failure of the book depends entirely on the careful choice of the topics and meticulous work of editors. Unfortunately, the book does not present a good example of the editorial job. All blemishes let this volume down and jeopardize and compromise well-written and informative articles. It is very sad that the good intentions were not matched by the result of the same quality.