Evolution of a Combinatorial Transcriptional Circuit: A Case Study in Yeasts

Evolution of a Combinatorial Transcriptional Circuit: A Case Study in Yeasts PDF Author: Annie E. Tsong
Publisher:
ISBN:
Category :
Languages : en
Pages : 352

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Book Description
Developing new regulation of existing genes is a major source of evolutionary novelty. In this thesis, I examine evolution of transcriptional regulation by dissecting a combinatorial regulatory circuit that governs mating-type in the ascomycete branch of the fungal lineage. I first determine the means by which four conserved transcription factors regulate mating-type in the pathogenic yeast C. albicans. I then closely compare the C. albicans circuit to that of S. cerevisiae, identifying several classes of changes that have arisen since their divergence from a common ancestor. Among the many changes identified, I focus on a group of orthologs, the a-specific genes, that is positively regulated in C. albicans, but is negatively regulated in S. cerevisiae. I demonstrate that positive regulation represents the ancestral form, and that the S. cerevisiae mode of negative regulation is a recently derived innovation. By examining the regulation of asgs in a group of 16 modern yeasts that diverged at successively later times from a common ancestor, I deduce specific, sequential changes in both cis- and trans-regulatory elements that constitute the transition from positive to negative regulation.

The Fungal Kingdom

The Fungal Kingdom PDF Author: Joseph Heitman
Publisher: John Wiley & Sons
ISBN: 1555819583
Category : Medical
Languages : en
Pages : 1161

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Book Description
Fungi research and knowledge grew rapidly following recent advances in genetics and genomics. This book synthesizes new knowledge with existing information to stimulate new scientific questions and propel fungal scientists on to the next stages of research. This book is a comprehensive guide on fungi, environmental sensing, genetics, genomics, interactions with microbes, plants, insects, and humans, technological applications, and natural product development.

Index Medicus

Index Medicus PDF Author:
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 2036

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Book Description
Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.

In the Light of Evolution

In the Light of Evolution PDF Author: National Academy of Sciences
Publisher: National Academies Press
ISBN: 030910405X
Category : Science
Languages : en
Pages : 379

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Book Description
In December 2006, the National Academy of Sciences sponsored a colloquium (featured as part of the Arthur M. Sackler Colloquia series) on "Adaptation and Complex Design" to synthesize recent empirical findings and conceptual approaches toward understanding the evolutionary origins and maintenance of complex adaptations. Darwin's elucidation of natural selection as a creative natural force was a monumental achievement in the history of science, but a century and a half later some religious believers still contend that biotic complexity registers conscious supernatural design. In this book, modern scientific perspectives are presented on the evolutionary origin and maintenance of complex phenotypes including various behaviors, anatomies, and physiologies. After an introduction by the editors and an opening historical and conceptual essay by Francisco Ayala, this book includes 14 papers presented by distinguished evolutionists at the colloquium. The papers are organized into sections covering epistemological approaches to the study of biocomplexity, a hierarchy of topics on biological complexity ranging from ontogeny to symbiosis, and case studies explaining how complex phenotypes are being dissected in terms of genetics and development.

Investigations in Yeast Functional Genomics and Molecular Biology

Investigations in Yeast Functional Genomics and Molecular Biology PDF Author: Matthew Eckwahl
Publisher: CRC Press
ISBN: 1771880104
Category : Medical
Languages : en
Pages : 414

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Book Description
This book examines conserved pathways mediating cell cycle progression and cell polarity establishment. It includes examples of yeast, regulatory circuits, and feedback regulation, with emphasis on system-wide approaches. It also covers protein interaction networks and trait locus analysis and presents methods and challenges in comparative genomics analysis and evolutionary genetics.

Candida and Candidiasis

Candida and Candidiasis PDF Author: Richard A. Calderone
Publisher: American Society for Microbiology Press
ISBN: 1555815391
Category : Medical
Languages : en
Pages : 1222

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Book Description
The underlying mechanisms of Candida and candidiasis and promising new directions in drug discovery and treatment. • Reviews all aspects of this common fungal pathogen and its impact on human health, from the basic biology of Candida albicans to the clinical management of candidiasis. • Reviews the latest basic and clinical research, focusing on findings in genome variability, host-pathogen interactions, antifungal resistance and drug discovery, and diagnostics to foster better understanding and treatment of candidiasis. • Examines recent discoveries that have shed light on morphogenesis and the cell cycle, including how new findings on host responses may have applications for the diagnosis of blood-borne candidiasis.

Fungal Genomics

Fungal Genomics PDF Author: Alistair J.P. Brown
Publisher: Springer Science & Business Media
ISBN: 3540308091
Category : Science
Languages : en
Pages : 283

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Book Description
Through the integration of bioinformatic, genetic, transcriptomic, proteomic, metabolomic, phenomic and other massive datasets, genomics is revealing exciting new insights into fungal cell biology. The central theme of this volume is the strong impact that genomics is having upon our understanding of fungal biology, across a wide range of species, including model yeasts (such as Saccharomyces cerevisiae and Schizosaccharomyces pombe), filamentous fungi (such as Neurospora crassa and Aspergillus nidulans) and pathogenic fungi (such as Magnaporthe grisae, Candida albicans, Cryptococcus neoformans and Histoplasma capsulatum). World-renowned scientists address the following topics in these fungi: systems biology and evolution, circadian rhythms, apoptosis and stress responses, secretion, and environmental signalling networks. Particular emphasis is placed on fungal pathogenicity. Various genomic technologies are discussed, including genome-wide sequence comparisons, transcript profiling, proteomics, metabolomics and bioinformatics.

Evolution of Virulence in Eukaryotic Microbes

Evolution of Virulence in Eukaryotic Microbes PDF Author: L. David Sibley
Publisher: John Wiley & Sons
ISBN: 1118308131
Category : Science
Languages : en
Pages : 912

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Book Description
A unique and timely review of the emergence of eukaryotic virulence in fungi, oomycetes, and protozoa, as they affect both animals and plants Evolution of Virulence in Eukaryotic Microbes addresses new developments in defining the molecular basis of virulence in eukaryotic pathogens. By examining how pathogenic determinants have evolved in concert with their hosts, often overcoming innate and adaptive immune mechanisms, the book takes a fresh look at the selective processes that have shaped their evolution. Introductory chapters ground the reader in principal evolutionary themes such as phylogenetics and genetic exchange, building a basis of knowledge for later chapters covering advances in genetic tools, how pathogens exchange genetic material in nature, and the common themes of evolutionary adaptation that lead to disease in different hosts. With the goal of linking the research findings of the many disparate scientific communities in the field, the book: Assembles for the first time a collection of chapters on the diversity of eukaryotic microorganisms and the influence of evolutionary forces on the origins and emergence of their virulent attributes Highlights examples from three important, divergent groups of eukaryotic microorganisms that cause disease in animals and plants: oomycetes, protozoan parasites, and fungi Covers how the development of genetic tools has fostered the identification and functional analyses of virulence determinants Addresses how pathogens exchange genetic material in nature via classical or modified meiotic processes, horizontal gene transfer, and sexual cycles including those that are cryptic or even unisexual Provides a broad framework for formulating future studies by illustrating themes common to different pathogenic microbes Evolution of Virulence in Eukaryotic Microbes is an ideal book for microbiologists, evolutionary biologists and medical professionals, as well as graduate students, postdoctoral fellows, and faculty members working on the evolution of pathogens.

Genome Plasticity and Infectious Diseases

Genome Plasticity and Infectious Diseases PDF Author: Jörg Hacker
Publisher: American Society for Microbiology Press
ISBN: 1555817084
Category : Medical
Languages : en
Pages : 547

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Book Description
Comprehensive examination of the current understanding of pathogen adaptation and microevolution. • Introduces the rapidly evolving field of genome plasticity, presents the latest research findings, and explores the relevance of these findings to infection and infection control. • Compiles and analyzes current investigations on the genome fluidity of pathogenic microbes. • Explores bacteria, viruses, fungi, and parasites from the aspect of host genome plasticity and its impact on infection.

A Mechanistic and Functional Study of White-opaque Phenotypic Switching in Candida Albicans

A Mechanistic and Functional Study of White-opaque Phenotypic Switching in Candida Albicans PDF Author: Mathew Gregory Miller
Publisher:
ISBN:
Category :
Languages : en
Pages : 730

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Book Description
Candida albicans is a major fungal pathogen of humans. It is a harmless commensal in healthy individuals, but it can cause serious infections in immune-compromised hosts. C. albicans undergoes a meta-stable and reversible switch between two distinct cell types known as white and opaque. The role of white-opaque switching in the biology of C. albicans was originally not well understood. We discovered an unexpected relationship between white-opaque switching and the sexual cycle of C. albicans . The mating type locus of C. albicans (MTL) encodes transcriptional regulatory proteins that regulate mating. We demonstrated that two MTL -encoded homeodomain proteins, a 1 and alpha2, work together to repress white-opaque switching in C. albicans . The observations that the MTL locus controlled both mating and white-opaque switching led us to hypothesize that opaque cells played a role in mating. Indeed, we found that opaque cells mate one million times more efficiently than do white cells. Additionally, opaque cells, but not white cells, developed specialized mating projections when exposed to mating pheromone. Thus, opaque cells are a specialized mating form of C. albicans . As white cells are generally more robust in a mammalian host than opaque cells, this strategy allows the organism to survive the rigors of life within a mammalian host, while generating a small population of mating-competent cells. The mechanism that controls white-opaque switching is not well understood. To better understand the mechanism, we investigated the regulation of white-opaque switching by a 1-alpha2. We demonstrated that a 1-alpha2 regulates white-opaque switching by destabilizing opaque cells, and we monitored gene expression during the transition from opaque to white using DNA microarrays. We used a candidate approach to identify additional regulators of white-opaque switching among genes enriched for their expression in the opaque phase. We identified two potent positive regulators of white-opaque switching: the opaque-specific transcriptional regulatory proteins Czf1 and Naf1. We also further investigated the role of Efg1, a previously identified regulator of white-opaque switching, and found that efg1/efg1 mutants were unable to bypass a 1-alpha2 repression of switching. Finally, we determined the epistatic and regulatory relationships between Efg1, Czf1 and Naf1.