REVIEWS The authors of The Molecular BiologF of Floweringpresent a worthy survey for
Flower biology blossoms
The MolecularBiologyof Flowering edited by Brian R. Jordan CAB Intemational, 1993. £45.00/$85.50 hbk (272 pages) ISBN 0 85198 723 0 The recent cloning of several floral homeotic genes has led flower biology into the mainstream of molecular genetics, and this facet of flower biology has been given much attention in the past few years. However, there is much more to flower biology than just the early development of single flowers, and the current emphasis on this has meant that other, equally fascinating, aspects of flower biology tend to get much less exposure than they deserve. Brian Jordan has edited a book that brings together a variety of topics in flower biology, from floral induction to the control of flower pigmentation, and reminds us that the field of flower biology encompasses more than the expression of a few transcription factors during early development. Tile only important topic missing is the reversion of flowering, which should have wammted a separate chapter. Many articles draw together developmental and physk)logical studies and tile results of molecular analyses, giving a perspective that is not merely molecular.
The Molecular BioloRv qf Fhm~,rinl.l is organized according to tile developmental progress of flowering, beginning with dlapters whose main foCLISis floral indttction, a process whose molecular tmderpimlings :ire as mysterious today as they were 20 years ago. Since hlochemical approaches to understanding floral induction have met with little success, tile best bet seems to lie in tile :malysis (ff mutations that affect tile time of flowering; :is described In detail by Colin Law, Caroline Dean and George Couphmd, this approach appears to be particularly promising in Ambidopsis. Several reviews deal with the isolation of genes on the basis of their differential expression during various phases of flower development. Although such screens have been successful, the study of the genes isolated has so far shed little light on the mechanisms that control flower development. Sharman O'Neill points out that one of tile more rewarding approaches has been the molecular analysis of genes defined by mutations that perturb normal development in Antirrhinum and Arabidopsis. The chapter I enjoyed most was the one on the control of flower coloration, written by Cathie MaRin and Tom Gerats. Synthesis of pigment in flowers is one of the few systems in
higher eukaryotes where mutations in both structural and regulatory genes have been identified, and where the interaction between these genes is beginning to be understood at the molecular level. As is often the case with multiauther volumes, the material presented could have been better coordinated: for example, strategies for isolating genes on the basis of their mutant phenotypes are discussed in at least three different chapters. Several reviews suffer from being too broad in scope, and the volume as a whole would have benefited from a more stringent discussion of the pertinent topics.
anyone who wants to get acquainted with genes involved in flowering. However, a recent (October 1993) issue of the journal The Plant Ceil, which reviewed plant reproduction, covers all the topics discussed here, and is not only more up-to-date but also considerably less expensive. You might find some additional information in this book, but I recommend you read it in the departmental library rather than buy !t for your bedside table.
Dedef Weigel Plant Biologylaboratory, The Saikhutitute for BiologicalStudies, 10010Notlh Tonw. PinesRoad, LaJolla, CA 92037, USA.
Basic Human Genetics by E.J. Mange and A.P. Mange Sinauer Associates, 1993. £29.95 hbk (491 pages) ISBN 0 87893 495 2 Textbooks on human genetics are almost invariably American in origin; it is hard to find one emanating from the UK. In the UK, the subject is taught predominantly to medical undergraduates and to young doctors in training, and is presented with an emphasis on medical aspects and inherited Iiuman :dmormality. This book is designed as a one-term course for 'students with diverse interests :rod no prior college I~Ioh~gyexperience', :t limited constituency outside North America. Whether we like it or not, in most other developed countries, the medical professkm has a tight grip on jobs that require expert knowledge of human genetics, and there is little scope for the science graduate within the existing structures. It seems sensible for a British reviewer to examine Basic Human Genetics from a local perspective. Would I recommend it to my medical students? The answer is: with some hesitation. It is a beautifully presented and finished book, with layout, line drawings and figures of an exceptional standard. The liberal use of boxes to encapsulate and highlight anecdotes relevant to the concepts explained in the text is a particularly attractive feature. All the facts necessary for a reasonable understanding of the principles of human genetics are adequately covered. The publishers must have produced the book with a speed unknown to their British counterparts so that, for example, the cloning of the gene
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involved in Huntington's disease gene in March 1993 is covered. My main reservation concerns the order in which the material is presented. This is not just a question of personal taste; it is a key to the proper understanding of the subject. At what point in the text should molecular genetics be introduced: at the very beginning, after chromosomes and cell division are discussed, or after mendelian principles are outlined? Mange and Mange opt for Chapter 12, more than half-way through tile book. Unfortunately, this comes after such topics as genomic imprinting, X chromosonle inactivation and the peculiar inheritance of tile fragile X syndrome have been covered, ahhough one cannot really begin to understand tllese witilout forward reference and some careftll reading of later cl~apters. Of course, genetics ilas evolved in sucil a way that rnolecul:lr biology has been a late arrival, and earlier treatments have often adopted a historical approach. But genetics is the science of inherited variation, and now that we have a sound knowledge of tile molecular basis of variation, wily not star by introducing DNA? Students have a right to be impatient with the preoccupations of their tutors on how the field unfolded. When there is a second edition of this superior book, as there doubtles:~ will be, the authors might consider a radical rearrangement of the chapters.
DavldJ.H,Brock Human GeneticsUnit.UnitersiO,of Edinburgh, WesternGeneralHospitaL Edinbur~b. UKEH42XU.