This book explores some of the latest research in the field of plant genomics with an emphasis on genome dynamics in Poaceae and the role of retroelements and polyploidy in establishing genome diversity. It comprises a collection of eleven short papers, including some by the finest practitioners of the subject. Most papers are of review style, although a few have included small amounts of new data. The book is not designed to be read from cover to cover as each paper stands alone, and whilst this leads to a little redundancy between chapters, the majority of papers are well worth the read. Several papers, such as those by Deragon et al. and Messing and Bennetzen, explore the contribution of transposable elements (especially retroelements) to angiosperm genome structure, diversity and evolution. The papers review a substantial body of evidence demonstrating that these elements are responsible for much of the genomic dynamism reported across angiosperms. At a more focused level, a review of the rice genome is provided by Sasaki, whilst an overview of current in-depth maize genomic research is given by Rafalski and Tingey. Further evidence of extensive genome fluidity and dynamism is also exhibited in terms of nuclear genome size. Grover et al.'s review clearly outlines our current understanding of the significant mechanisms that have contributed to the overall pace and direction of genome size change (both up and down) over evolution. The other substantial component of angiosperm genome structure that is explored is polyploidy (or whole-genome duplication), which has so characterized and shaped angiosperm divergence. The paper by Paterson describes the impact of paleopolyploidy on angiosperm diversity, while Sampedro and Cosgrove outline how the collinear organization of genes in duplicated syntenic blocks can be used to infer evolutionary relationships between species, and the particular pitfalls that may arise using such approaches. The fate of duplicated genes has been the focus of much research and the excellent paper by Freeling examines different hypotheses (i.e. gain-of-function, subfunctionalization, and balanced-gene-drive) that have been proposed to explain patterns of duplicate-gene retention following polyploidy. Analysing the increasing amounts of comparative sequence data being generated, Freeling concludes that balanced-gene-drive rather than subfunctionalization is the most likely mechanism responsible for duplicate-gene retention. In addition to these central foci in the book, there is a paper on plant sex chromosomes by Charlesworth and one on plant centromeres by Lamb et al. The latter explores exactly what the plant centromere is, with recent data clearly showing that this essential structure is largely the product of epigenetic modifications rather than genetic sequence. There is also a paper on small interfering RNAs by Meyers et al. that provides a valuable marker for the state-of-knowledge in this young, but undoubtedly important field in relation to genome dynamics. Unfortunately the paper is likely to age rapidly. Overall, the book presents us with state-of-the-art information in most areas of plant genome dynamics. We say ‘in most areas’, however, because there is nothing significant on tandem repeats, which comprise a substantial fraction of plant genomes, and it does not mention ribosomal DNA (rDNA) or telomeres, despite significant advances in our understanding of their evolutionary and functional dynamics over the last few years. Furthermore there is no allusion to the avalanche of high-throughput sequence data that is on the brink of arriving. The quality of the presentation is high, although there could have been a bit more editorial intervention in places to strengthen or remove a few weak sections to some manuscripts that crept through, and to enhance poorly explained figures. Nevertheless the book is free of minor errors and this small criticism should not deter the reader from buying this specialist book. This book is suitable for anyone with a research or high-level teaching interest in genome dynamics in angiosperms. In summary, this book effectively establishes that the angiosperm genome is highly dynamic, and provides insights into the key processes and mechanisms that contribute to that dynamism, particularly polyploidy and retroelements. It provides a good overall marker of our current knowledge in most areas. We are pleased to have read it and feel it would make a valuable addition to our collection or a library.
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Dec 1, 2009
James A Birchler + 1
Open Access