(ed) Methods in Cell Biology 28 New York: Academic Press, 1987If the cell biologist interested in fundamental processes, such as chemosensory perception, intracellular signal transduction, cell motility and cellular differentiation was asked to design the ideal subject for study then an organism closely akin to DictyosteUum would be the probable result. These aspects of cell behaviour are deeply rooted in evolution and the fundamental mechanisms and macromolecular components involved are likely to be conserved in all eukaryotes. DictyosteUum engages in activities, such as chemotaxis and cellular differentiation, which lie beyond the capabilities of yeast and it offers the enormous advantage, over higher eukaryotes, of haploid genetics; allowing the ready isolation of mutants using both classical and molecular genetical approaches.The biological insights gained using DictyosteUum are summarized in a series of review articles published elsewhere in book form (Loomis, 1982, The Development of DictyosteUum discoideum, Academic Press) which, despite the major advances made since its publication, still offers the best introduction to the organism. The present publication is in a sense a companion volume, since it tells one how to work with Dictyostelium. It should have two major uses. It will allow the already committed readily to move sideways into unfamiliar territories and, hopefully, the availability of a speciesspecific cookbook will encourage those with a problem best studied in Dictyostelium to utilize the organism.The book opens with a witty, and highly readable, distillation by the now retired Maurice Sussman of a scientific lifetime’s experience of growing Dictyostelium cells and inducing them to undergo synchronous development. The following sections combine some background information with highly detailed protocols and relevant experimental results. There is, of course, an inevitable degree of heterogeneity in the general relevance and depth of coverage of the various procedures described. Many laboratories, with different fundamental interests, are likely to benefit from the insightful chapter on classical genetics or from the comprehensive description of methods used to analyse components of the cAMP signal transduction pathway. In contrast, it seems likely that only the cognoscenti will benefit from the section on amino terminal processing of actin, or the chapter describing the preparation of deuterated actin. The heavy emphasis on cell motility is, perhaps, inevitable given the interests of the editor but this is an area where Dictyostelium does hold great potential and the book does succeed in adequately covering the very broad spectrum of activities in the field. There are small overlaps between some of the chapters but the book in no way suffers from this. No two investigators utilize precisely identical techniques to solve the same problem and it is often very informative to compare exact procedures and the rationale behind them.The chapters are generally clearly written and they are packed with the kind of invaluable tips which should greatly reduce the effort and frustration normally attendant on introducing a new technique into a laboratory. One notable exception is a somewhat vacuous, and several times ill informed, section on molecular cloning by differential screening. Fortunately, the other, much more extensive, section on molecular biological procedures is highly informative. It is firmly rooted in the general experience of cloning genes in Dictyostelium that, while cDNA cloning is straightforward, genomic cloning must be approached very carefully because of the extremely high AT content of intergenic regions. It is this kind of organism-specific information which will make this book so invaluable and which is present, to a greater or lesser extent, in all of the contributions.There is one very serious error in the book. The high AT content of Dictyostelium is reflected in an enormously skewed codon usage. This allows the accurate prediction of synthetic oligonucleotide probes from conserved regions of genes previously sequenced in other organisms. This approach has been used to clone a number of Dictyostelium genes. The two most skewed codon sets are those encoding glu and gin. In a compilation of the codon usage in known Dictyostelium genes the codons for glu and gin are interchanged. It is to be hoped this potentially disastrous error will be made widely known and rectified in any subsequent editions.The final section describes work from the editor’s laboratory which gave the first indication that homologous recombination occurs with very high (c. 10%) efficiency when genes are introduced into Dictyostelium by transformation. The fruits of this enormously powerful tool are now beginning to flower in similar observations for other important genes. The isolation of Dictyostelium mutants is straightforward, but their analysis using classical genetics is much more cumbersome than in yeast. The ‘reverse’ genetic approach described above for analysing the function of cloned genes suggests that the best is yet to come in studying fundamental problems of cell biology in Dictyostelium.