BOOK REVIEWS 663 work well together in helping to explain a potentially diffi- applying the most appropriate transfer methods for their cult area. The 3 chapters on topoisomerases (unlinking of experimental system. The strength of this manual is that, DNA by topoisomerases, gyrase and reverse gyrase) mean in most of its parts, it addresses the three essential ques- that this book is very useful for those interested in this tions a laboratory manual should answer: What is the area. Similarly, this book is very good for those with an potential of a technique, how does it work, step-by-step, interest in HMG-box , which are discussed in 3 and what can go wrong? Surprisingly, the book does not chapters. Perhaps the nicest chapter in the book is on the contain an index, which certainly would have been helpful. E. coli cyclic AMP receptor by Busby, Koib and Updated protocols on -mediated Buc. This is a very focused chapter containing some very transfer and the various forms of direct DNA transfer into nice figures and is ideal for those wishing to get up-to- protoplasts, plastids or tissue, provide valuable and date in this area. detailed sources of information. However, no laboratory To my mind the value of a book such as this is to manual is fully comprehensive, and this book is no excep- provide more or less up-to-date summaries of research tion. Some important transfer techniques are missing, areas that can be understood by the non-expert. For the such as the Ca-aliginate method for embedding Arabi- most part this book is successful in this respect with most dopsis protoplasts, first published by the Willmitzer lab, or of the chapters being clear, straightforward and not overly the co-cultivation technique for plant protoplasts and long. Another opportunity that such a book provides is Agrobacterium, as nicely applied for activation tagging by the possibility of utilising plenty of illustrations that R. Walden and his co-workers. Also, no examples of the wouldn't perhaps otherwise be allowed in a research use of viral transformation vectors are given. article or review. I was pleased to see that the book has In addition to three small chapters on embryonic 101 figures (compared with 82 in the previous volume) culture, genetic markers and biosafety aspects, the book and 12 of these are in colour. The use of colour illustra- contains a larger section with a summary of protocols for tions is to be particularly applauded as these really help to the analysis of transgenic plants, accompanied by a short bring certain chapters alive (notably the ones on gyrase discussion about the stability of transgenic traits. It is and the cyclic AMP receptor protein). especially valuable for those molecular protocols that In summary this book works well and is worthwhile. By cannot readily be found in common molecular necessity the topics covered are selective and, for manuals, such as enzyme assays or in situ hybridization example, RNA does not get much of an airing and drugs techniques. Other techniques, like Southern, Northern or get almost none at all. But there is always next year! Western blot hybridization, various modifications of which TONY MAXWELL have been published elsewhere, might be used by the Department of Biochemistry readers for comparison to choose the method most suit- University of Leicester able for their particular plant system. For example, not Leicester LEJ 7RH everybody will find 20 p1 to be the optimum volume for UK digestion of 10 pg genomic DNA. The relatively poor quality of the discussion about stability, probably reflects the lack of knowledge about this topic at the time the article was written. The Gene 'fransfer to Plants. Ingo Potrykus and German book mentions terms like co-suppression and trans-inacti- Spangenberg (eds). Springer-Verlag, Berlin. 1995. Pp. 361. vation, but it ignores many of the publications that have Price DM 128.00, ringbound paperback. ISBN 3 540 elucidated the underlying mechanisms in recent years. To 58406 4. address the area of gene silencing in a way suitable for a laboratory manual, it might be appropriate for a revised An important factor for progress in plant sciences, has version to add plant-specific protocols for the analysis of been the continuously broadening spectrum of new plant DNA-methylation, transcription and RNA-turnover. transformation techniques. A laboratory manual that PETER MEYER provides the latest update of DNA transfer protocols will Centre for Plant Biochemistry and therefore be highly appreciated both by beginners and Department of Biology veterans. Those who are not put off by the relatively high University of Leeds price of the book will find it most helpful for selecting and Leeds LS2 9JT UK.

The Genetical Society of Great Britain, Heredity, 77, 66 1—664.