Bacteria in various habitats are subject to continuously changing environmental conditions, such as nutrient deprivation, heat and cold stress, UV radiation, oxidative stress, dessication, acid stress, nitrosative stress, cell envelope stress, heavy metal exposure, osmotic stress, and others. In order to survive, they have to respond to these conditions by adapting their physiology through sometimes drastic changes in gene expression. In addition they may adapt by changing their morphology, forming biofilms, fruiting bodies or spores, filaments, Viable But Not Culturable (VBNC) cells or moving away from stress compounds via chemotaxis. Changes in gene expression constitute the main component of the bacterial response to stress and environmental changes, and involve a myriad of different mechanisms, including (alternative) sigma factors, bi- or tri-component regulatory systems, small non-coding RNA’s, chaperones, CHRIS-Cas systems, DNA repair, toxin-antitoxin systems, the stringent response, efflux pumps, alarmones, and modulation of the cell envelope or membranes, to name a few. Many regulatory elements are conserved in different bacteria; however there are endless variations on the theme and novel elements of gene regulation in bacteria inhabiting particular environments are constantly being discovered. Especially in (pathogenic) bacteria colonizing the human body a plethora of bacterial responses to innate stresses such as pH, reactive nitrogen and oxygen species and antibiotic stress are being described. An attempt is made to not only cover model systems but give a broad overview of the stress-responsive regulatory systems in a variety of bacteria, including medically important bacteria, where elucidation of certain aspects of these systems could lead to treatment strategies of the pathogens. Many of the regulatory systems being uncovered are specific, but there is also considerable “cross-talk” between different circuits. Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria is a comprehensive two-volume work bringing together both review and original research articles on key topics in stress and environmental control of gene expression in bacteria. Volume One contains key overview chapters, as well as content on one/two/three component regulatory systems and stress responses, sigma factors and stress responses, small non-coding RNAs and stress responses, toxin-antitoxin systems and stress responses, stringent response to stress, responses to UV irradiation, SOS and double stranded systems repair systems and stress, adaptation to both oxidative and osmotic stress, and desiccation tolerance and drought stress. Volume Two covers heat shock responses, chaperonins and stress, cold shock responses, adaptation to acid stress, nitrosative stress, and envelope stress, as well as iron homeostasis, metal resistance, quorum sensing, chemotaxis and biofilm formation, and viable but not culturable (VBNC) cells. Covering the full breadth of current stress and environmental control of gene expression studies and expanding it towards future advances in the field, these two volumes are a one-stop reference for (non) medical molecular geneticists interested in gene regulation under stress.

Transcriptome analysis is the study of the transcriptome, of the complete set of RNA transcripts that are produced under specific circumstances, using high-throughput methods. Transcription profiling, which follows total changes in the behavior of a cell, is used throughout diverse areas of biomedical research, including diagnosis of disease, biomarker discovery, risk assessment of new drugs or environmental chemicals, etc. Transcriptome analysis is most commonly used to compare specific pairs of samples, for example, tumor tissue versus its healthy counterpart. In this volume, Dr. Pyo Hong discusses the role of long RNA sequences in transcriptome analysis, Dr. Shinichi describes the next-generation single-cell sequencing technology developed by his team, Dr. Prasanta presents transcriptome analysis applied to rice under various environmental factors, Dr. Xiangyuan addresses the reproductive systems of flowering plants and Dr. Sadovsky compares codon usage in conifers.

Transcriptomics and gene expression profiling enables the elucidation of the genetic response of an organism to various environmental cues. Transcriptomics enables the deciphering of differences between two closely related organisms to the same environment and in contrast, enables the elucidation of genetic responses of the same organism to different environmental cues. Two major methods are utilized for the study of transcriptomes, high-throughput sequencing and microarray analysis. High-throughput sequencing technologies such as the Illumina platform are relatively new and protocols must be developed for the analyses of transcriptomes (RNA-sequencing). A RNA-seq protocol was developed and refined for the Illumina sequencing platform. This protocol was then utilized for the de novo sequencing of the steelhead salmon transcriptome. Hatchery steelhead exhibit a reduced fitness compared to wild steelhead that has been shown to be genetically based. Consequently, the steelhead transcriptome was assembled, annotated, and used to identify gene expression differences between hatchery and wild fish. We uncovered many differentially expressed genes involved in metabolic processes and growth and development. This work has created a better understanding of the genetic differences between hatchery and wild steelhead salmon. Brachypodium distachyon is a monocot grass important as a model for cereal crops and potential biofuels feedstocks. To better understand the genetic response of this plant to different environmental cues, a comprehensive assessment of the transcriptomic response was conducted under a variety of conditions including diurnal/circadian light/dark/temperature environments and different abiotic stress conditions. Using a whole-genome tiling DNA microarray, we identified that the majority of transcripts in Brachypodium exhibit a daily rhythm in their abundance that is conserved between rice and Brachypodium. We also identified numerous cis-regulatory elements dictating these rhythmic expression patterns. We also identified the genetic response to abiotic stresses such as salinity, drought, cold, heat, and high light. We uncovered a core set of genes which responds to all stresses, indicating a core stress response. A large number of transcription factors were uncovered as potential nodes for regulating the abiotic stress response in Brachypodium. Moreover, promoter elements that drive specific responses to discrete abiotic stresses were uncovered. Altogether, the transcriptome analyses in this work furthers our understandings of how particular organisms respond to environmental cues and better elucidates the relationship between genes and the environment.

Changes in Eukaryotic Gene Expression in Response to Environmental Stress focuses on various aspects of eukaryotic cell's response to heat stress (shock) and other stress stimuli. This book is organized into two major sections, encompassing 17 chapters that reflect the emphasis on research utilizing Drosophila, a variety of animal systems, and plants. This book first provides a brief introduction to the organization, sequences, and induction of heat shock proteins and related genes. It then describes the control of transcription during heat shock from the standpoint of molecular biology and evolutionary variations of the mechanisms in organisms with diverse metabolic needs. It goes on to discuss the issue of coordinate and noncoordinate responses of heat shock genes. It presents a model for post-transcriptional regulation on certain aspects of coordinate and noncoordinate regulations. Chapters 6-12 discuss heat shock proteins and genes and the effects of stress on gene expression of sea urchin, avian, and mammalian cells. The second part of the book focuses on the physiological role of heat shock proteins and genes in plants and fungi. It includes a discussion on experimental problems encountered during studies of the mechanisms of inhibition of photosynthesis by unfavorable environmental conditions. The changes in transcription and translation of specific mRNAs in the developing embryo during heat shock at various temperatures are described. The concluding chapters deal with heat shock response in plants, particularly the response in soybeans and maize, covering both physiological and molecular analyses. Research scientists, clinicians, and agriculturists will greatly benefit from the information presented in this book.

Transcriptome Profiling: Progress and Prospects assists readers in assessing and interpreting a large number of genes, up to and including an entire genome. It provides key insights into the latest tools and techniques used in transcriptomics and its relevant topics which can reveal a global snapshot of the complete RNA component of a cell at a given time. This snapshot, in turn, enables the distinction between different cell types, different disease states, and different time points during development. Transcriptome analysis has been a key area of biological inquiry for decades. The next-generation sequencing technologies have revolutionized transcriptomics by providing opportunities for multidimensional examinations of cellular transcriptomes in which high-throughput expression data are obtained at a single-base resolution. Transcriptome analysis has evolved from the detection of single RNA molecules to large-scale gene expression profiling and genome annotation initiatives. Written by a team of global experts, key topics in Transcriptome Profiling include transcriptome characterization, expression analysis of transcripts, transcriptome and gene regulation, transcriptome profiling and human health, medicinal plants transcriptomics, transcriptomics and genetic engineering, transcriptomics in agriculture, and phylotranscriptomics. Presents recent development in the tools and techniques in transcriptomic characterization Integrates expression analysis of transcripts and gene regulation Includes the application of transcriptomics in human health, genetic engineering and agriculture