Hail again the double helix

It has been more than half a century since the molecular biology revolution was ushered in by James Watson and Francis Crick's discovery of the double helix. Arguably, the Nobel prize of the 20th century was their reward (and that of their collaborator, Maurice Wilkins).

In every high school, college and university that teaches biology, students learn about DNA, its sister molecule RNA and the proteins that are translated from it. Not surprisingly, this has spawned a cottage industry of textbooks, large and small, geared to every conceivable facet of molecular genetics. My office shelves are full of such tomes - thick, glossy, beautifully illustrated, with associated CD-Roms and websites espousing the wonders of the subject to undergraduates, postgraduates and professors.

So do we need any more? The answer is "yes", because this research field moves so fast that the shelf life of such a text is barely more than four to five years. Sandy Primrose and Richard Twyman's Principles of Gene Manipulation and Genomics is now in its seventh edition, years after the first. It clearly is something of an updated hybrid between the sixth edition of Principles of Gene Manipulation and the third edition of Principles of Genome Analysis and Genomics by the same authors. I also detected a little influence from their other text Genomics: Applications in Human Biology .

Just to add to this Primrose and Twyman orgy of print, they have yet another text out, Gene and Genome Technology , which as far as I can see is identical to Principles of Gene Manipulation and Genomics , except that in the former there are a few questions asked after each chapter, and the sepia figure colours of the latter are replaced with full colour.

Confused by this crisis of identity? I know I am. Whichever of the two recent P&Ts you select, the texts are divided into four sections, the first dealing with basic molecular techniques such as electrophoresis, PCR, cutting and sticking molecules together in vectors, sequencing and so on, plus some basic bioinformatics. This is followed by a description of the tricks of modern transgenic methods in the major model systems, microbes, yeast, vertebrates, flies and plants.

We then move on to "omics" - genomics, transcriptomics, a large chunk on proteomics, including "interactomics" meaning yeast two hybrid screens, and metabolomics. Finally, there is an "applications" section, in which genomics are used to identify the underlying genetic basis of polygenic characters, and the discussion continues somewhat haphazardly with further chapters on pharmacogenetics, bioreactors and useful novel recombinant molecules, agronomics, and gene therapy and disease cure and prevention.

As with previous texts written by Primrose, the subjects are discussed in enough detail to stimulate first to final-year biology and genetics undergraduates and will also help to remind research students about some of the basics they have forgotten.

The glossier version does have some irritations. The main sub-headings within chapters are in a feeble thin orange that is barely legible. In addition, most of the page numbers are on the inside margins, so it's impossible to quickly find the page you want by scanning the corners as you flick through. It doesn't help either that the chapter titles are not presented at the top of every page. Having these beautiful colour images is terrific, but unfortunately any lecturer interested in stealing them for PowerPoint presentations to their classes will be disappointed because there is no associated CD-Rom or website (as far as I can see) by which to easily download them. Less forgivingly, there is no index. Although this may be nitpicking, this text looks like it was rushed out prematurely for Christmas, and I definitely prefer their less glossy 2006 seventh edition.

Terry Brown's Genomes 3 has none of these irritations - everything from the index to page numbers to colour figures is fully and easily accessible.

There is a CD-Rom inserted that has all the figures as PowerPoint and jpeg presentations. Answers to questions posed at the end of every chapter are provided in the appendix, and more detailed guidance is available if you adopt the book and ask. Again, the book is in four sections: "Studying genomes", which has lots of basics and methodology; "Genome anatomy" (all about human, pro, eukaryotic and viral genome organisation); "How genes function" (chromatin, transcription initiation, transcriptome, proteome, and gene regulation); and "How genomes replicate and evolve"

(recombination, repair, mutation, phylogenetics, RNA world, first cells, phylogenetics).

It will have a broad appeal to all levels of biology undergraduates, even the more zoologically inclined, who these days will be unable to avoid learning about molecules. However, even they will be happy with the substantial chapters on evolution, which is afforded considerably more space than in P&T's book.

Which one would I buy? Certainly, for any biology student interested in molecular genetics, Brown cuts the mustard. Having said that, P&T would appeal more to a final-year honours student because the subject matter is a little more advanced than in Brown.

Given how nicely P&T is presented, it's such a pity that a little more attention to detail was not paid to it by the publishers and authors.

Perhaps the next edition of Gene and Genome Technology will become a student favourite.

Finally, Gene Cloning: Principles and Applications by Julia Lodge, Pete Lund and Steve Minchin also landed on my desk. Unlike Genomes 3 and Principles of Gene Manipulation and Genomics (or Gene and Genome Technology if you prefer), this is not a comprehensive text and requires a certain amount of prior knowledge, but nothing more than a second-year undergraduate should command. It begins with basic genome organisation, GC content, CpG islands, chromatin and moves effortlessly into cloning, making and screening libraries, gene tagging, sequencing, bioinformatics, gene expression, transgenic organisms and forensic and medical applications.

Had I ever been a practical molecular biologist, this is the book that would reassure me of the principles behind my experiments. Furthermore, if, for example, I wanted to find the transcription starting point of a gene (the position in DNA where a gene starts to be read into mRNA), this would tell me the theory behind how to do it. Thus it is not a lab cookbook or manual, but a very user-friendly and helpful adviser. I was rather impressed with this book and will suggest it as a text, not only for my second and third-year students but also for our MSc molecular genetics course.

Charalambos P. Kyriacou is professor of behavioural genetics, Royal Society, and a Wolfson research fellow.