Molecular medicine, volume 2

T I G - AI~! 1988, Vol. 4, no. 4

Pathogens in the field Diseases and Plant Population Biology byJeremyJ. Burdon, Cambridge University Press, 1987. £27.50/$49.50 hbk, £12.50/$19.95 pbk (w~i + 208 pages) ISBN. 0 521 31615 4

There is excellent literature ov the genetics of host-parasite interactions that makes the study of the population genetics of plants and pathogens very attractive. Many studies on population biology deal only with the influence of components of the system on changes in numbers or density of the target organism. With plant host-pathogen systems, there is the opportunity to study changes in gene frequencies in populations as well as changes in total numbers or density of a particular species. The book leads up to this analysis without tip.allygetting to it. An example of how such a study could have been used to determine influences of a pathogen on the population genetics on a host, and the influenceof a particular host on the population genetics of a pathogen, might have been a tremendous stimulus

book review s

to entice both plant pathologists to think more of population biology, and population biologists (geneticists in particular) to see the opportunities of studying plant-pathogen interactions. The book is sufficientlywell written to be enjoyable, reading for advanced undergraduates, graduate students and established researchers and teachers. It brings together in a lucid manner the concepts of several areas of plant pathology and plant biology, giving a broad overview but with sufficient detail to encourage readers to pursue the literature further.

The influence of plant pathogens on the population biology of plants can be considered as both extensively studied and basically ignored. From the view of an agricultural setting, there have been extensive studies on the influence of pathogens on a population of plants of limited genetic diversity, but in contrast there is a dearth of information on the ALBERT H. ELLINGBOE influence of pathogens on plants in a Depa~,nt of Plant Patl~lo~, Russell native setting. The agriculturallyfocused Laboratories, 1630 Linden Drive, Madison, studies have also been biased in that the W153706, USA. principal interest has been to determine the economic importance of pathogens and the means to control the losses due to therrL This has clearly taken priority New directions for medical research over an understanding of how the pathogen affects the plant in its environ- Molecular Medicine, Volume 2 transcriptional activators of other genes, ment. and the regulation of expression of the This book attempts to focus on the edited by Alan D. B. Malcolm, IRLpress hsp genes themselves. It will be of means by which pathogens have been 1987. £22.50/$40.00 (pbk) (viii + 124 interest to the clinician to know that the shown to or may affect the size and pages) ISBN 0 947946 58 6 hsp genes can also be induced by ethanol genetic structure of plant populations, One of the most exciting developments in and other noxious substances such as the competition in plant communities, medical research today is the application heavy metals, some anaesthetics, anoxia their distribution in different environ- of molecular biology to an ever- and certain drugs. Burdon speculates ments, etc. It does so by beginning with increasing number of diseases. This that heat shock proteins may have some very elementary considerations of volume deals with four areas of medicine significant roles in growth and developwhat pathogens do to plants. Examples that have very little in common except ment and even in the origin of neoplasia. are given of specializationof pathogens to that i n each of them the application of If it were possible to suppress the heat specific parts of plants, parts of the life molecular biology has already produced shock response in turnour cells, they cycle of plants, and some of the significantresults. The topics covered in might be ~endered more sensitive to manifestations of disease on the natural the four chapters are hyperthermia and cytotoxic agents. Atherosclerosis is the most common history of plants. It proceeds to give a its use in cancer therapy, the molecular description of the components and genetics of lipid metabolism and its cause of death in Western countries. development of epidemics and how relation to circulatory diseases, inherited Fresh impetus was given to the role. of epidemics of pathogens might affect plant disorders of blood coagulation and the genetics in disord6rs of lipid metabolism populations. It then moves into the design and development of new vaccines. when Brown and Goldstein demongenetics of interactions between host and Hyperthermia has been used in one strated that the cell membrane receptor pathogen, the environmental modifica- form or another for the treatment of for low density lipoprotein was partially tion of host-pathogen interactions, the cancer over the past hundred years. At or completely absent in the rare condition effects of pathogens on plant populations, first it had no biological rationale, the known as homozygous familial hyperand the effects of plants on pathogen results were unpredictable and any cholesterolaemia. In this disorder, populations. benefit was usually transient. In the past severe atherosclerosis, including coronThe outline of this hook is a logical twenty years, however, the techniques ary heart disease, develops at a very progression from effects at the level of have been quantified and a possible young age. James Scott summarizes the the individual to the level of the genetic biological basis for this form of treatment present state of knowledge of the structure of plant and pathogen popula- has emerged. Cells which have been molecular genetics of the apollpoprotions. The beginning sections consist of exposed to elevated temperatures in teins, the enzymes and the receptors traditional plant pathology and include vitro recover from the initial damage and now known to be involved in the various hypotheses both supported and unsup- in the process they acquire tolerance to genetic abnormalities of lipid.~"~.tabolism. ported by critical experimental analysis. continued or repeated heat applications. Although it is still not clear to what extent These early chapters will make easy This phenomenon is known as the heat genetically determined lipid and lipoproreading for plant pathologists and provide shock response and its molecular basis is tein abnormalities contribute to the a simple explanation of what plant dealt with in detail by Roy Burdon in the aetiology of atherosderotic vascular pathology is all about for the nonpath- first chapter. Both normal and abnormal disease, Scott predicts that "the clear ologists. They represent an excellent tissues respond to elevated tempera- understanding of g e n e s . . , will allow synthesis of the classical areas of plant tures by increased synthesis of proteins, refinement of diagnosis, early prediction pathology research, areas that interact including a group known as the heat of risk and improvement of therapy". shock proteins 0isp). The genes for This must surely be one of the most only infrequently. In contrast, I consider the treatment of some hap appear to have been highly important areas for molecular medicine the genetics of interactions to be weak; conserved in evolution and they probably research. The third chapter, by Peake and different genetic concepts are given have a critical role in cell protection. The equal weight whether or not they are chapter describes molecular aspects of Liddell, deals thoroughly and comprehensupported by careful analytical research. hsp function including their role as sively with haemophilia A, haemophilia B " ~ , ~

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April 1988, Vol. 4, no. 4

that play a large part in the development It should be very useful to both clinicians ase and defects in other blood and eventual use of a vaccine. Added to and research workers with an interest in coagulation factors, both congenital and these are the high costs of safety testing the subjects that it covers, but it is also of acquired. The treatment of the and of distributing vaccines in countries general interest since it clearly indicates haemophilias has attracted much pub- with limited health care facilities. the direction that medical research is now licity recently because of the risk of the However, the prospects for the pro- taking. transmission of AIDS by blood trans- duction of safe and effective vaccines WILLIAM H. PRICE fusion and factor VIII concentrates. The designed by molecular biologists appear need for virus-free materials has to be excellent. Department of Medicine (Western General This volume has been well edited and Hospital), UniversityofEdinburgh, Edinburgh emphasized the importance of bioengineered factors VIII and IX, and a all four chapters are eminently readable. EH4 2XU, UK. n ~ b e r of c a ~ e r c i ~ companies are engaged in trying to meet this need. The The good, the not so good and the trivial authors also describe in detail the application of molecular genetics to From Genes to Clones: Introduction of the 17 chapters for, unlike, From Genes to Clones this text is quite prenatal diagnosis and carrier detection to Gene Technology in the haemophilias. There are by Emst-L. Winnacker, VCH Verlag, readable. The chapters treat diverse undoubted advantages, but the limita- 1987. DM 60pbk, DM12O hbh (xiii + 634 techniques from ELISA to footprinting, from monoclonal antibodies to the tions of these new methods should also pages) ISBN 3 527 26644 5 chemical synthesis of ofigndeoxyribunucbe appreciated. For successful prenatal diagnosis, the mother has to be heterozy- Techniques in Molecular Biology leotides, and from Ti plasmids to bacteriophage ~. However the problem is guns for both the diseased gene and the Vol. 2 that the mix is too diverse and that the marker gene. Ideally, the marker should be an intragenic polymorphism but these edited by John M. Walker and Wim treatment is too patchy. Assuming, first, are fewer than had been expected. Also, Gaastra, Croom Helm, 1987. £14.95 pbk, that a worker could locate the chapter the three intrageuic factor IX poly- £30.00 hbh (iv + 332pages) ISBN 0 7099 about, say, the chemical synthesis of oligonucleotides, he or she is not going to morphisms have been found to be in 3673 7 linkage disequilibrium, so if a mother is Everyone knows that the trouble with find a 22 page review very helpful. If you homozygous for one she stands a greater most books about molecular biology is want to know the basics you look in a chance of being homozygous for the that they date very quickly, they are textbook, if you want to practise the others. If the marker is extragenic there rarely comprehensive and it is usually technique you find a manual! Similarly, I is still a significant and for some an impossible to put your finger on the exact find it hard to befieve that short chapters unacceptable error in carrier detection piece of information that you desperately on cloning in ~. or Ti plasmids will find and prenatal diagnosis, l'hus, although need. Wirmacker's From Genes to Clones many fans. The criticism really is thai: tile the conventional methods of prenatal is a bold attempt to solve at least the book falls between two stools and I diagnosis and carder detection, which latter two problems and is probably the expect will be bought mainly by libraries are also described in this chapter, cannot best value, in terms of pennies per page, and others who already have volume 1. I be used before the second trimester of currently available. Potential readex~ think I would keep my £14.95 to spend on pregnancy and have other disadvantages should not be misled by the inclusion of another book, say one of the IRL as well, they should not be abandoned yet 'introduction' in the title: in fact this book methods series, and hope the library since DNA studies are not applicable in all covers most aspects of cloning in buys this one. families. Everyone knows that trivial things can remarkable detail. My first reaction to The last chapter deals with the design this book was that it was a poor sequel to sometimes command undeserved attenof new vaccines and the challenge it Old and Primrose (Principles of Genetic tion. This was confirmed for me as, after presents to molecular biology. Few Manipulation, Blackwell Scientific Publi- each read of From Genes to Clones, I methods of treatment can have a better cations). However, over a number of found myself thumbing through the text testimony than the success of the use of weeks I have warmed to the text and now to look over the dozens of quarter-page vaccination in the eradication of small- reach for it regularly to check out the size mug-shots of all our heroes, from ~ x . Nor could there be a stronger 'state of play' on particular points for the Khorana to Komberg, Sanger to Gilbert, incentive to the production of new lab or for lectures. Maniatis to Messing. This is a new idea, vaccines than the menacing threat of the The book covers most aspects of perhaps inspired by Cold Spring Harbor, human immunodeficiency virus (HIV), isolation, identification and characteriza- and one of which the younger scientists the aetiological agent of AIDS. In his tion of DNA fragments, including chap- portrayed may not approve in years to highly informative review, Mackett ters on chemical synthesis and sequence come. Actuallythe highlight of the photos describes the impact of the new technol- determination. Vectors for E. coil, is that of Tbeodor Eschefich (1857ogies on vaccine design. There is a wide Gram-positive bacteria, Streptomy- 1911), of whose existence I and all in my diversity of possible approaches: gen- cetes, yeasts and higher eukaryotes laboratory had been hitherto totally etically engineered proteins can be used (including plants) are described, together unaware. At last we shall know whom to as subunit vaccines; synthetic peptides with their manipulation to make express- curse when trying to spell the name of with the same amino acid sequence as the ion systems. Later chapters cover our favourite bacterium[ Another examantigenic regions of the infecting organ- mutagenesis techniques, the applications ple of this 'trivia of sorts' is the inclusion isms can be used for active immunization; of recombinant DNA to medicine (treated of 18 pages of microtype carrying the anti-idiotype antibodies can be used for a little shabbily in my view) and, NIH guidelines for research involving the same purpose; the attenuation of the significantly, sections on safety. I cannot recombinant DNA, signed by Thomas E. virulence of live vaccines can be fault the author on his choice of material. Malone. Considering the hours and genetically engineered and vectors such However, be wvrned: predictably, the money spent, and reams of paper spilt as as the vaccinia virus can be engineered to text is extremely tedious in places and a result of these guidelines, Mr Malone serve as vehicles for other vaccine the book does not make good fireside can consider himself unlucky indeed that antigens. This is an impressive array of reading! his photo is not also included. possible methods of vaccine production Unhappily, several weeks' acquaintSTEVE BUSBY but in his concluding paragraph Mackett ance has not mellowed my opinion of Department of Biochemistry, University of reminds us of the medical, political, volume 2 of Techniques in Molecular Birmingham, PO Box 363, Birmingham econornic and sociological considerations Biology. Actually I enjoyed reading most B15 2TT, UK.