Cell Movements: from Molecules to Motility (2nd Edition)

by Dennis Bray

Garland Publishing (2001) 372 pages. ISBN 0-8153-3282-3


‘All mankind is divided into three classes: those that are immovable, those that are movable, and those that move’.

If only Benjamin Franklin had laid his hands on a copy of Cell Movements by Dennis Bray, he might have been tempted to change ‘mankind’ to ‘life’ and add the caveat ‘but on the whole, pretty much everything is in the last class.’ One case, then, in which ignorance is bliss. For the rest of us, however, Cell Movements is more of a lesson that ‘ignorance is embarrassing’, and what better way to avoid the embarrassment than digging deep into this new edition?

In a personable preface that sets the tone for the rest of the book, Bray points out that much has changed in the ten years since the first edition of Cell Movements was published. In this time, more than a thousand papers have been published on the actin cytoskeleton alone, a rate of discovery that ought to render most textbooks outdated as soon as they are published. Amazingly, however, Cell Movements is extremely up to date, the only significant failing being its publication date – fractionally too early to take advantage of the draft human genome sequence and provide a more thorough list of the players that may be involved in cell movement. Bray has also achieved the remarkable feat of producing a textbook that is, almost in its entirety, an entertaining read. This is undoubtedly a reflection of his own enthusiasm, which shines through in his witty and informative prose – few scientific authors would be brave enough to talk about ‘queenly’ microtubules, ‘peanut-shaped’ domains or, my favourite, the cell’s ‘elastic stocking’ cortex.

Cell Movements provides a timely prod for many of us who have been blinkered by the pace of discovery and now find ourselves thinking that cell movement is only the actin tail of Listeria or the formation of a contractile fibre. Bray has no such tunnel vision, and his definition of cell movement ranges from mitosis to bacterial chemotaxis, taking in gastrulation, cytoplasmic streaming and swimming protozoa along the way. The book is divided into 20 chapters, arranged in three (rather arbitrary) parts. All the usual suspects are here – the actin cytoskeleton (together with its associated actin-binding proteins and a comprehensive chapter on myosins), microtubules and centrosomes, rocketing bacteria and crawling amoebae. But Bray has also incorporated a wide range of ‘movement machines’ often neglected by other texts. For example, there is a thorough discussion of cilia and flagella, both in eukaryotic and bacterial cells, as well as entire chapters on muscle development and cell movement in embryos.

Most impressive are the occasional forays into mathematics, found mainly in Chapters 1, 2 and 18. Biophysicists and ‘true’ biologists often make unhappy bedfellows, each thinking the other to be overlooking the ‘reality’ of cell biology. Bray, however, provides a lucid description of diffusion, viscosity, motor efficiency and the myriad of other forces that govern movement at the cellular scale. He also deserves considerable praise for discussing cytoplasmic structure and pointing out that ‘the concentration of protein in the cytoplasm is much higher than that used in most biochemical experiments [and]… is closer to that at which proteins crystallize.’

Throughout the book there are comments, anecdotes and footnotes that liven up the text whilst providing excellent memory aids. One is left with the impression of a talented, avuncular professor spilling forth a lifetime’s learning onto the page – stories are told with wit and vigour but in a rather random order. That is not to say that Cell Movements is haphazard – a detailed contents page and index, plus the ingenious use of two or three word ‘footers’ on the odd-numbered pages, which describe the topic therein (‘Keratin and vimentin’ or ‘Ciliary growth’, for example), make it easy to locate individual subjects. Like all writing styles, Bray’s encounters the occasional problem – for example, the microtubule-organising centre is first mentioned on page 249, 60 pages after the section on microtubules – and there are sporadic flashes of verbiage that may make life slightly tricky for readers with English as a second language. This is, however, a small price to pay for the highly readable prose.

At the end of each chapter there is a list of essential concepts – concise take-home messages that will undoubtedly be silently thanked by multitudes of overworked students. Equally valuable are the numerous tables, particularly those listing components of various cellular machines (focal adhesions or adherens junctions, for example) – though I suspect that those readers deep in a nocturnal essay crisis would have appreciated a separate contents page listing all of these tables. Each chapter also has a paragraph of ‘Outstanding Questions’, and in this situation both interpretations of ‘outstanding’ would be valid. As well as summarising many of the unanswered questions in the field (for example, ‘How are the ends of microtubules attached to kinetochores?’), Bray comes up with some novel puzzles, such as ‘Why do yew trees make a microtubule-stabilising poison?’ or ‘Why does smooth muscle have such a confusing variety of control mechanisms?’

Unfortunately, the otherwise excellent presentation of Cell Movements is let down on three points. Firstly, the frequent footnotes, which are in themselves highly informative, are denoted in the text by an easily missed superscript, meaning that backtracking is required if one wishes to find out which part of the text the footnote refers to. A second criticism, common to many textbooks, is its paperback format – my copy is already somewhat battered after a single reading. Thirdly, and most disappointingly, there are no colour figures. This is more than an aesthetic point – some of the artwork becomes difficult to understand in shades of grey, and the diagram of a focal adhesion (p90) is a veritable nightmare without colour! This is a real shame, since in all other respects ‘Cell Movements’ is on a par with that bible of cell biology, Molecular Biology of the Cell.

For undergraduates specialising in cell motility or bacterial chemotaxis, Cell Movements would be a good investment, and at £29.95 it won’t eat too far into the student grant. For those embarking on research in the cell movement field, it provides a wide-ranging and friendly review, plus plenty of ‘fascinating facts’ to liven up dinner parties. For those already firmly entrenched in the field it ought to be compulsory reading – few of us can hope to rival Bray’s encyclopaedic knowledge, but at least we can glimpse the bigger picture.