This volume focuses on mitochondrial RNA metabolism, emphasizing recent discoveries and technological advances in this fast moving area that increase our understanding of mitochondrial gene function. Topics addressed include the interplay of mitochondria with the nucleus and cytosol, structure-function connections, and relevance to human disease. Mitochondria are the powerhouses of the cell, and a great deal is known about mitochondrial energy metabolism. Less well known is the plethora of amazing mechanisms that have evolved to control expression of mitochondrial genomes. Several RNA processes and machineries in protozoa, plants, flies and humans are discussed, including: transcription and RNA polymerase mechanism; tRNA processing of 5′ and 3′ ends; mRNA maturation by nucleotide insertion/deletion editing and by RNA splicing; mRNA stability; and RNA import. Specialized factors and ribonucleoproteins (RNPs) examined include pentatricopeptide repeat (PPR) proteins, RNase P, polymerases, helicases, nucleases, editing and repair enzymes. Remarkable features of these processes and factors are either not found outside mitochondria, differ substantially among eukaryotic lineages, or are unique in biology.

Trypanosomes are unicellular protozoa of ancient evolutionary origin that are responsible for several tropical diseases, such as African sleeping sickness. Over the last few decades, research in trypanosome biology has revealed many unique and fascinating features, many of which have helped to establish new paradigms in other biological systems. This applies in particular to studies in gene expression and regulation, which benefit enormously from the trypanosome genome projects and from the new genome-wide approaches recently introduced in trypanosome research. This volume covers the most important aspects of biosynthesis, processing, and functions of RNA in trypanosomes, ranging from transcription to RNA editing, mRNA splicing/translation/turnover, processing of transfer and ribosomal RNA, RNA interference, and current transcriptome-wide analyses. Recent progress in RNA-focused research in trypanosomatids promises to yield novel insights into trypanosome-specific features, as well as to reveal in the process new potential therapeutic strategies for combating these parasitic diseases.

It has become evident over the last years that abnormalities in RNA processing play a fundamental part in the pathogenesis of neurodegenerative diseases. Cellular viability depends on proper regulation of RNA metabolism and subsequent protein synthesis, which requires the interplay of many processes including transcription, pre--‐mRNA splicing, mRNA editing as well as mRNA stability, transport and translation. Dysfunction in any of these processes, often caused by mutations in the coding and non--‐ coding RNAs, can be very destructive to the cellular environment and consequently impair neural viability. The result of this RNA toxicity can lead to a toxic gain of function or a loss of function, depending on the nature of the mutation. For example, in repeat expansion disorders, such as the newly discovered hexanucleotide repeat expansion in theC9orf72 gene found in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), a toxic gain of function leads to the formation of RNA foci and the sequestration of RNA binding proteins (RBPs). This in return leads to a loss of function of those RBPs, which is hypothesized to play a significant part in the disease progression of ALS and FTD. Other toxicities arising from repeat expansions are the formation of RNA foci, bi--‐directional transcription and production of repeat associated non--‐ATG (RAN) translation products. This book will touch upon most of these disease mechanisms triggered by aberrant RNA metabolism and will therefore provide a broad perspective of the role of RNA processing and its dysfunction in a variety of neurodegenerative disorders, including ALS, FTD, Alzheimer’s disease, Huntington’s disease, spinal muscular atrophy, myotonic dystrophy and ataxias. The proposed authors are leading scientists in the field and are expected to not only discuss their own work, but to be inclusive of historic as well as late breaking discoveries. The compiled chapters will therefore provide a unique collection of novel studies and hypotheses aimed to describe the consequences of altered RNA processing events and its newest molecular players and pathways.

Mycology, the study of fungi, originated as a subdiscipline of botany and was a descriptive discipline, largely neglected as an experimental science until the early years of this century. A seminal paper by Blakeslee in 1904 provided evidence for self incompatibility, termed "heterothallism", and stimulated interest in studies related to the control of sexual reproduction in fungi by mating-type specificities. Soon to follow was the demonstration that sexually reproducing fungi exhibit Mendelian inheritance and that it was possible to conduct formal genetic analysis with fungi. The names Burgeff, Kniep and Lindegren are all associated with this early period of fungal genetics research. These studies and the discovery of penicillin by Fleming, who shared a Nobel Prize in 1945, provided further impetus for experimental research with fungi. Thus began a period of interest in mutation induction and analysis of mutants for bio chemical traits. Such fundamental research, conducted largely with Neurospora crassa, led to the one gene: one enzyme hypothesis and to a second Nobel Prize for fungal research awarded to Beadle and Tatum in 1958. Fundamental research in biochemical genetics was extended to other fungi, especially to Saccharomyces cere visiae, and by the mid-1960s fungal systems were much favored for studies in eukaryotic molecular biology and were soon able to compete with bacterial systems in the molecular arena.

Mitochondria in plants, as in other eukaryotes, play an essential role in the cell as the major producers of ATP via oxidative phosphorylation. However, mitochondria also play crucial roles in many other aspects of plant development and performance, and possess an array of unique properties which allow them to interact with the specialized features of plant cell metabolism. The two main themes running through the book are the interconnection between gene regulation and protein function, and the integration of mitochondria with other components of plant cells. The book begins with an overview of the dynamics of mitochondrial structure, morphology and inheritance. It then discusses the biogenesis of mitochondria, the regulation of gene expression, the mitochondrial genome and its interaction with the nucleus, and the targeting of proteins to the organelle. This is followed by a discussion of the contributions that mutations, involving mitochondrial proteins, have made to our understanding of the way the organelle interacts with the rest of the plant cell, and the new field of proteomics and the discovery of new functions. Also covered are the pathways of electron transport, with special attention to the non-phosphorylating bypasses, metabolite transport, and specialized mitochondrial metabolism. In the end, the impact of oxidative stress on mitochondria and the defense mechanisms, that are employed to allow survival, are discussed. This book is for the use of advanced undergraduates, graduates, postgraduates, and beginning researchers in the areas of molecular and cellular biology, integrative biology, biochemistry, bioenergetics, proteomics and plant and agricultural sciences.