Mobile Genetic Elements: Protocols and Genomic Applications brings together a wide array of transposon-based protocols and stategies for studying genome structure, function, and evolution into a highly practical, single-source volume. Such transposable element (TE)-derived techniques have been applied succe- fully for a variety of purposes ranging from mutagenesis, gene silencing, transgenesis, and their use as polymorphic marker systems. To our knowledge no such synthesis has been presented before. Chapters 2-4 provide a series of DNA hybridization techniques for anal- ing the distribution and dynamics of mobile DNAs at the hosts' genomic level. With the current revolution in genomics and the availability of complete genome sequences, computational analyses provide an extremely powerful tool for i- lating and investigating TEs at the in silico level (Chapter 5). For the analyses of transpositional mechanisms at the biochemical level Chapter 6 provides a detailed protocol for LTR retrotransposons in heterologous host systems. Ch- ters 7-10 are focused on TE-based mutagenesis protocols for studying gene functions in a broad range of organisms. Based on their ubiquitous nature and their activity in creating genomic diversity by integrating novel DNA segments into genomes, TEs provide highly informative sets of polymorphic markers (Chapters 11-13). Finally, the last two chapters are dedicated to their technical applications during transgenesis in arthropods and vertebrates.

Mobile Genetic Elements: Protocols and Genomic Applications brings together a wide array of transposon-based protocols and stategies for studying genome structure, function, and evolution into a highly practical, single-source volume. Such transposable element (TE)-derived techniques have been applied succe- fully for a variety of purposes ranging from mutagenesis, gene silencing, transgenesis, and their use as polymorphic marker systems. To our knowledge no such synthesis has been presented before. Chapters 2-4 provide a series of DNA hybridization techniques for anal- ing the distribution and dynamics of mobile DNAs at the hosts' genomic level. With the current revolution in genomics and the availability of complete genome sequences, computational analyses provide an extremely powerful tool for i- lating and investigating TEs at the in silico level (Chapter 5). For the analyses of transpositional mechanisms at the biochemical level Chapter 6 provides a detailed protocol for LTR retrotransposons in heterologous host systems. Ch- ters 7-10 are focused on TE-based mutagenesis protocols for studying gene functions in a broad range of organisms. Based on their ubiquitous nature and their activity in creating genomic diversity by integrating novel DNA segments into genomes, TEs provide highly informative sets of polymorphic markers (Chapters 11-13). Finally, the last two chapters are dedicated to their technical applications during transgenesis in arthropods and vertebrates.

During the last 50 years, the perception oftransposable elements (TEs) has changed considerably from selfish DNA to sequences that may contribute significantly to genome function and evolution. The recent increased interest in TEs is based on the realization that they are a major genetic component (at least 10--20%) of all organisms and a major contributor to the mutation process. It is currently estimated that 70--80% of spontaneous mutations are the result of TE-mediated insertions, deletions, or chromosomal rearrangements. Thus, it seems at least plausible that TEs may playa significant role in the adaptation and evolution of natural populations and species. The ubiquity of TEs suggests that they are an old component of genomes which have been vertically transmitted through generations over evolutionary time. However, detailed analyses carried out over the last 20 years have revealed several unusual features of TE evolution: (i) TEs can be horizontally transferred between species; (ii) TE evolutionary rates can be dramatically increased by specific inactivation processes, such as the RIP (Repeat Induced Point mutation) mechanism in fungi; (iii) TEs can influence the regulation of other TEs by insertion or deletion; (iv) different classes of TEs in even distantly related species can be remarkably similar in both structure and function.

This book brings together most of the information available concerning two species that diverged 2-3 million years ago. The objective was to try to understand why two sibling species so similar in several characteristics can be so different in others. To this end, it was crucial to confront all data from their ecology and biogeography with their behavior and DNA polymorphism. Drosophila melanogaster and Drosophila simulans are among the two sibling species for which a large set of data is available. In this book, ecologists, physiologists, geneticists, behaviorists share their data on the two sibling species, and several scenarios of evolution are put forward to explain their similarities and divergences. This is the first collection of essays of its kind. It is not the final point of the analyses of these two species since several areas remain obscure. However, the recent publication of the complete genome of D. melanogaster opens new fields for research. This will probably help us explain why D. melanogaster and D. simulans are sibling species but false friends.