Neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. Here, we report a high-quality draft sequence of the N. crassa genome. The approximately 40-megabase genome encodes about 10,000 protein-coding genes-more than twice as many as in the fission yeast Schizosaccharomyces pombe and only about 25% fewer than in the fruitfly Drosophila melanogaster. Analysis of the gene set yields insights into unexpected aspects of Neurospora biology including the identification of genes potentially associated with red light photobiology, genes implicated in secondary metabolism, and important differences in Ca(2+) signalling as compared with plants and animals. Neurospora possesses the widest array of genome defence mechanisms known for any eukaryotic organism, including a process unique to fungi called repeat-induced point mutation (RIP). Genome analysis suggests that RIP has had a profound impact on genome evolution, greatly slowing the creation of new genes through genomic duplication and resulting in a genome with an unusually low proportion of closely related genes
The organization of biological activities into daily cycles is universal in organisms as diverse as cyanobacteria, fungi, algae, plants, flies, birds and man. Comparisons of circadian clocks in unicellular and multicellular organisms using molecular genetics and genomics have provided new insights into the mechanisms and complexity of clock systems. Whereas unicellular organisms require stand-alone clocks that can generate 24-hour rhythms for diverse processes, organisms with differentiated tissues can partition clock function to generate and coordinate different rhythms. In both cases, the temporal coordination of a multi-oscillator system is essential for producing robust circadian rhythms of gene expression and biological activity.The temporal coordination of internal biological processes, both among these processes and with external environmental cycles, is crucial to the health and survival of diverse organisms, from bacteria to humans. Central to this coordination is an internal CLOCK that controls CIRCADIAN RHYTHMS of gene expression and the resulting biological activity (BOX 1). Despite disparate phylogenetic origins and vast differences in complexity among the species that show circadian rhythmicity, at the core of all circadian clocks is at least one internal autonomous circadian OSCILLATOR. These oscillators contain positive and negative elements that form autoregulatory feedback loops, and in many cases these loops are used to generate 24-hour timing circuits 1, 2 . Components of these loops can directly or indirectly receive environmental input to allow ENTRAINMENT of the clock to environmental time and transfer temporal information through output Competing interests statementThe authors declare no competing financial interests. NIH Public Access Author ManuscriptNat Rev Genet. Author manuscript; available in PMC 2009 September 1. Published in final edited form as:Nat Rev Genet. 2005 July ; 6(7): 544-556. doi:10.1038/nrg1633. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript pathways to regulate rhythmic clock-controlled gene (CCG) expression and rhythmic biological activity.Whereas a self-contained clock in single-celled organisms programmes 24-hour rhythms in diverse processes, multicellular organisms with differentiated tissues can partition clock function among different cell types to coordinate tissue-specific rhythms and maintain precision. Now that individual molecular circadian oscillators have been sufficiently described, it has become possible to go beyond single oscillators to try and understand how multiple oscillators are integrated into circadian systems. Evidence accumulated in recent years indicates that the intracellular oscillator systems of single-celled organisms might be more complex than those of higher eukaryotes, whereas the complexity of circadian outputs in multicellular organisms is an emergent property of intercellular interactions. In this review, we discuss the complexity of the circadian clocks on the basis of molecular genetic and geno...
The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation.The aspergilli are a ubiquitous group of filamentous fungi spanning over 200 million years of evolution. Among the over 185 aspergilli are several that have an impact on human health and society, including 20 human pathogens as well as beneficial species used to produce foodstuffs and industrial enzymes 1 . Within this genus, A. nidulans has a central role as a model organism. In contrast to most aspergilli, A. nidulans possesses a well-characterized sexual cycle and thus a well-developed genetics system. Half a century of A. nidulans research has advanced the study of eukaryotic cellular physiology, contributing to our understanding of metabolic regulation, development, cell cycle control, chromatin structure, cytoskeletal function, DNA repair, pH control, morphogenesis, mitochondrial DNA structure and human genetic diseases.We present here the genome sequence for A. nidulans, and a comparative genomics study with two related aspergilli: A. fumigatus 2 and A. oryzae 3 . A. fumigatus is a life-threatening human pathogen, and ARTICLES
We present an analysis of over 1,100 of the ∼10,000 predicted proteins encoded by the genome sequence of the filamentous fungus Neurospora crassa. Seven major areas of Neurospora genomics and biology are covered. First, the basic features of the genome, including the automated assembly, gene calls, and global gene analyses are summarized. The second section covers components of the centromere and kinetochore complexes, chromatin assembly and modification, and transcription and translation initiation factors. The third area discusses genome defense mechanisms, including repeat induced point mutation, quelling and meiotic silencing, and DNA repair and recombination. In the fourth section, topics relevant to metabolism and transport include extracellular digestion; membrane transporters; aspects of carbon, sulfur, nitrogen, and lipid metabolism; the mitochondrion and energy metabolism; the proteasome; and protein glycosylation, secretion, and endocytosis. Environmental sensing is the focus of the fifth section with a treatment of two-component systems; GTP-binding proteins; mitogen-activated protein, p21-activated, and germinal center kinases; calcium signaling; protein phosphatases; photobiology; circadian rhythms; and heat shock and stress responses. The sixth area of analysis is growth and development; it encompasses cell wall synthesis, proteins important for hyphal polarity, cytoskeletal components, the cyclin/cyclin-dependent kinase machinery, macroconidiation, meiosis, and the sexual cycle. The seventh section covers topics relevant to animal and plant pathogenesis and human disease. The results demonstrate that a large proportion of Neurospora genes do not have homologues in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. The group of unshared genes includes potential new targets for antifungals as well as loci implicated in human and plant physiology and disease
Light signaling pathways and circadian clocks are inextricably linked and have profound effects on behavior in most organisms. Here, we used chromatin immunoprecipitation (ChIP) sequencing to uncover direct targets of the Neurospora crassa circadian regulator White Collar Complex (WCC). The WCC is a blue-light receptor and the key transcription factor of the circadian oscillator. It controls a transcriptional network that regulates ϳ20% of all genes, generating daily rhythms and responses to light. We found that in response to light, WCC binds to hundreds of genomic regions, including the promoters of previously identified clock-and lightregulated genes. We show that WCC directly controls the expression of 24 transcription factor genes, including the clock-controlled adv-1 gene, which controls a circadian output pathway required for daily rhythms in development. Our findings provide links between the key circadian activator and effectors in downstream regulatory pathways.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.