Galun, E. Transposable elements. A guide to the perplexed and the novice. With Appendices on RNAi, chromatin remodeling and gene tagging

Abstract

True to the subtitle, ‘A guide to the perplexed and the novice’, Professor Esra Galun’s real life novel(!) on transposable elements (TEs) provides a good coverage of the subject to a wide audience. This book contains a full description of all known transposable elements, their modes of transposition and their utilization in medicine, genetics and crop improvement. It also contains appendices on RNAi, chromatin remodelling and gene tagging which are appropriately pitched for the novice but probably not good enough for the perplexed, as things are progressing very fast in those fields. A brief introduction (Chapter 1), with due emphasis on Barbara McClintock’s enormous contribution to the understanding of ‘transposable elements’ (referred to as ‘controlling elements’ by her), is followed by some historical background (Chapter 2) which provides brief accounts of hybridization and inheritance before Mendel, Mendel’s revolution, between Mendel and genetics, and from static genes to mobility wherein McClitock’s ‘controlling elements’ and her perception on gene regulation (which perhaps was not that well understood or appreciated by geneticists of her time) are documented. Transposable elements per se are covered in three chapters in great detail, namely bacterial insertion sequences (Chapter 3), retrotransposons (Chapter 4) and Class II transposable elements in eukaryotes (Chapter 6), with a short chapter on telomeres and transposable elements (Chapter 5). Naming of the chapters and chapter subheadings are inconsistent and somewhat unconventional. The author probably did this intentionally, keeping the ‘novice’ in mind as a target audience. Although the author gives credit solely to Barbara McClintock for the development of pre‐molecular concepts on mobile elements in the introductory chapters, equally important contributions of others (people like P. A. Peterson) are adequately covered in Chapter 5. A recent article by Peterson (2002) is worth reading to know more about controversies surrounding early studies on mobile elements. In view of the importance of the silencing and activation of TEs in evolution, the appendices of this book on RNAi and chromatin remodelling are very useful complementary materials for the ‘novice’ to understand the role of these effectors, along with transposable elements, in the evolution of organisms. For more conceptual and technical details on RNAi the ‘perplexed’ may read Waterhouse et al. (2001), Hannon (2002) and Cerutti (2003). Similarly, suggested reading for chromatin remodelling‐related topics is Grewal and Moazed (2003) and Fischle et al. (2003). Investigation of transposable elements is now a live area of research in molecular biology as they are not only driving forces for genome evolution, but are also versatile tools for functional genomics. As pointed out by the author, with the availability of near‐complete genome sequences in the model crops—rice (monocot model) and Arabidopsis (dicot model)—insertion mutants can be effectively used in gene identification using the ‘forward genetics’ approach. Several laboratories, including my own (Upadhyaya et al. 2002, 2003), are now producing Ds insertion lines with specially designed constructs and compiling databases of sequences flanking each of these insertions, associated mutant phenotypes, and associated gene trap reporter expression patterns. Once a substantial number of insertion lines are produced it will be possible to use pooled DNA from these insertion lines in gene identification using a ‘reverse genetics’ approach. Perhaps these aspects are not covered appropriately in this book. Nevertheless, for a novice the book will provide an overview of gene tagging. Overall, this book should attract a broad readership, although this is likely to be via the library bookshelf as it is rather pricey for the average reader to purchase their own personal copy.