Horizontal Gene Transfer

12 Key excerpts on "Horizontal Gene Transfer"

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  Biotechnological Approaches in Crop Protection

  • Prasad, D(Authors)
  • 2021(Publication Date)
  • Biotech

    (Publisher)

  M. Syvanen in 1985 proposed this mechanism as “cross species gege transfer”. And finally Hilario and Gogartan in 1993 first time use the term “Horizontal Gene Transfer” for this conflictive events. 1. HGT is the non-genealogical transmission of genetic material from one organism to another. 2. It is a source of new genetic material to the recipient. 3. It is a mechanism that permits the acquisition of evolutionary novelties. 4. It is common mechanism of gene transfer in bacteria and archaea and around 70-80 per cent gene transfer takes place through HGT. On the basis of time HGT is divided into two types as ancient and recent: Ancient HGT Genes transferred between organisms separated a long time ago. The ancient HGT is difficult to detect through codon usage bias and differential base composition because genes are ameliorated. Recent HGT Genes transferred between organisms separated recently. Recent gene transfer is easy to detect based on Criteria of codon usage bias and differential base composition as the gene are not ameliorated. In bacteria HGT is happened in three ways as transformation, transduction and conjugation: Transformation is the incorporation of exogenous genetic material from its surrounding through the cell wall by recipient bacterium (Frederick Griffith, 1928). Transduction is the injection of foreign DNA by a bacteriophage virus This ebook is exclusively for this university only. Cannot be resold/distributed. into the recipient bacterium (Joshua Lederberg, 1946). Conjugation is the transfer of genetic material between two bacterial cells in direct contact by a conjugation tube or a bridge(Joshua Lederberg, 1956). Figure 15.1 showing bacterial transformation, transduction and conjugation The photosynthetic sea slug Elysia chlorotica appears like a dark green leaf as a result of retaining chloroplasts from its algal prey, Vaucheria litorea , in cells lining of its digestive tract.

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  Polar Microbiology

  The Ecology, Biodiversity and Bioremediation Potential of Microorganisms in Extremely Cold Environments

  • Asim K. Bej, Jackie Aislabie, Ronald M. Atlas(Authors)
  • 2009(Publication Date)
  • CRC Press

    (Publisher)

  7.2 Horizontal Gene Transfer The classical transmission of genetic information occurs vertically from parent to offspring within a specific species. Horizontal Gene Transfer (HGT), also known Possible Role of Bacteriophage-Mediated Horizontal Gene Transfer 181 as lateral gene transfer (LGT), refers to the passage of genetic information from one organism to another that may be closely or only distantly related (Johansen and Ustaheim 1968, Jain et al. 1999, Ochman et al. 2000, Koonin et al. 2001). HGT, along with associated mutations and genome reorganization, is now known to be a ubiqui-tous, central survival mechanism capable of producing rapid adaptive responses in eukaryotes, prokaryotes, and viruses (Zeph et al. 1988, Medigue et al. 1991, Davison 1999, Choi and Kim 2007). The impact of HGT first became apparent during the genomic analyses of clinically significant pathogenic organisms (Saunders et al. 2001, Schmidt 2001). Novel epidemics, the appearance of new pathogenic strains in nonpathogenic bacteria, and the rapid spread of drug resistance have all been attributed to HGT (Dowson et al. 1989, 1990, Jiang and Paul 1998, Jain et al. 1999, Koonin et al. 2001). 7.2.1 M ECHANISMS Prokaryotes have a wide range of mechanisms available for the exchange of genetic information including processes such as conjugation, transformation, and transduc-tion (Mindlin et al. 2002). However, for organisms inhabiting extreme environments, the first two possibilities, conjugation and transformation, are not particularly effi-cient methods for information transmission. Conjugation requires direct cell-to-cell contact between a donor bacterium harboring fertility plasmids and recipient organ-isms expressing the appropriate pilus receptor. Multiple examples of information transfer by conjugation have been observed in laboratory settings, but are more dif-ficult to document in the field (Dahlberg et al. 1998, Marcinek et al. 1998, Hausner and Wuertz 1999).

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  Microbiology and Nanobiology: Advancing Frontiers

  • Kumar, Har Darshan(Authors)
  • 2021(Publication Date)
  • Daya Publishing House

    (Publisher)

  In this transformation, the most critical role will be played by Horizontal Gene Transfer (HGT) involving the non-genealogical transfer of genetic material from one organism to another– e.g. , from one bacterium to another or from viruses to bacteria. HGT is pervasive and powerful among many prokaryotes in which it accelerates the spread of antibiotic resistance. In fact, the prevalence of HGT argues against regarding microbes as organisms dominated by individual characteristics; rather their communications by genetic or quorum-sensing channels point to the fact that microbial behaviour should be understood as predominantly cooperative. This ebook is exclusively for this university only. Cannot be resold/distributed. In the wild, microbes form communities, invade biochemical niches and drive biogeochemical cycles. There are strong indications that microbes absorb and discard genes as needed, in response to their environment. Rather than discrete genomes, there is a continuum of genomic possibilities, which throws doubt on the applicability of the concept of a ‘species’ to microbes (Goldenfeld and Woese, 2007). One recent example of this idea emerged in the study of genomes recovered from natural samples as opposed to clonal cultures–studies of the spatial distribution of rhodopsin genes in marine microbes suggest such genes to be ‘cosmopolitan’, wandering among bacteria (or archaea) as environmental pressures dictate. Another exciting finding is that viruses have a fundamental role in the biosphere, in both immediate and long-term evolutionary senses. They are an important repository and memory of a community’s genetic information, contributing to the system’s evolutionary dynamics and stability. This is suggested, for example, by prophage induction, in which viruses lying latent in cells can become activated by environmental influences; the resulting destruction of the cell and viral replication is an effective mechanism for the dispersal of host and viral genes.

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  Disinfection of Root Canal Systems

  The Treatment of Apical Periodontitis

  • Nestor Cohenca(Author)
  • 2014(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  Figure 3.4 ).

  Figure 3.4

  Horizontal Gene Transfer of DNA. The bacterial cells are represented by the green and purple ovals. The DNA is represented by the helix. Transposons and plasmids are either blue bars or circles. The arrows show the direction of transfer of the DNA. (a) Transformation: the donor cell (top left) has lysed and the DNA released into the environment. This can be taken up by competent bacteria and incorporated into the recipient genome; (b) conjugation of plasmids through a pilus; (c) conjugation of transposons via a mating pore; (d) transduction mediated by the injection of DNA by a bacteriophage.

  (Reprinted with permission from Roberts AP, Mullany P. Oral biofilms: a reservoir of transferable, bacterial, antimicrobial resistance. Expert Review of Anti-Infective Therapy 8(12):1441–1450. Expert Reviews Ltd © 2010.)

  Biofilm growth has been shown to enhance genetic exchange via transformation, as demonstrated in several streptococcal species naturally competent for transformation (42, 43). However, the most efficient HGT process in bacteria is conjugation, with the requirement for cell-to-cell contact distinguishing conjugation from transduction and transformation (Figure 3.4 ). The ability of plasmids to conjugatively transfer between species has been demonstrated in oral streptococci (44–46), and between Treponema denticola and Streptococcus gordonii in experimental biofilms (47). In the endodontic microflora, several enterococcal isolates recovered from patients in Sweden exhibited a characteristic response to enterococcal-derived pheromone that supported the possibility of highly efficient pheromone-induced conjugative transfer of genetic elements in RC infections (48). This premise was subsequently supported in an ex-vivo model through the demonstration of bidirectional transfer of a conjugative plasmid in RCs occurring between S. gordonii and Enterococcus faecalis (49) (Figure 3.5

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  Biotechnology and Bioinformatics

  Advances and Applications for Bioenergy, Bioremediation and Biopharmaceutical Research

  • Devarajan Thangadurai, Jeyabalan Sangeetha, Devarajan Thangadurai, Jeyabalan Sangeetha(Authors)
  • 2014(Publication Date)
  • Apple Academic Press

    (Publisher)

  CHAPTER 7 AN INSIGHT INTO Horizontal Gene Transfer TRIGGERING WIDESPREAD ANTIMICROBIAL RESISTANCE IN BACTERIA ZAKIR HOSSAIN CONTENTS 7.1 Introduction .................................................................................. 180 7.2 Plasmid Biology ........................................................................... 181 7.3 Role of Plasmid in Antimicrobial Resistance .............................. 183 7.4 Mechanisms of Bacterial Conjugation ......................................... 187 7.5 Tools for Studying Resistance Transfer ....................................... 192 7.6 Conclusion ................................................................................... 193 Keywords .............................................................................................. 194 References ............................................................................................. 194 180 Biotechnology and Bioinformatics 7.1 INTRODUCTION Rapid distribution of antimicrobial resistance among bacterial populations currently poses a major therapeutic challenge worldwide. A lot of extensive research has been carried out to understand the potential factors attribut-ing this resistance. Horizontal Gene Transfer (HGT), also called lateral gene transfer (LGT), via the process known as conjugation or mating has been established as the predominant reason for the dissemination of antibiotic re-sistance through bacterial species (OECD, 2010; Malik et al ., 2008). This phenomenon refers to a unidirectional exchange (donor to recipient) of ge-netic material between closely related or phylogenetically distant organisms. Mobile genetic elements (MGEs) or mobilomes, such as plasmids or conjuga-tive transposons of bacteria can be transferred from a donor to a recipient by conjugation, which has been described as intimate physical contact between bacterial populations due to the activity of specialized protein complex, mat-ing pair formation (Mpf) system.

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  Smart Bioremediation Technologies

  Microbial Enzymes

  • Pankaj Bhatt(Author)
  • 2019(Publication Date)
  • Academic Press

    (Publisher)

  Böhne, Brunet, Galiana-Arnoux, Schultheis, & Volff, 2008 ) and play a significant role in HGT. Bacterial genomes evolve through mutations, rearrangements, or HGT. HGT produces extremely dynamic genomes in which substantial amounts of DNA are introduced into and deleted from the chromosome. HGT is widely recognized as the mechanism responsible for the widespread distribution of antibiotic resistance genes, gene clusters encoding biodegradation pathways, and pathogenicity determinants, thus effectively changing the ecological and pathogenic character of bacterial species. Infrequently, such new bacterial genotypes establish and spread in the larger population through either positive selection or random genetic drift.

  19.2 Mechanism of Horizontal Gene Transfer

  HGT between bacteria in natural habitats is largely mediated by MGEs, such as self-transmissible plasmids, transposons, integrons, ISs, genomic islands, and bacteriophages. Three main mechanisms of HGT have been described: transformation, transduction, and conjugation.

  1. 1. Transformation involves the uptake of naked DNA from the environment and has the potential to transmit DNA between very distantly related organisms. Certain bacterial species, such as Neisseria gonorrhoeae and Haemophilus influenzae , are perpetually competent to accept DNA, whereas others, such as Bacillus subtilis and Streptococcus pneumoniae , become competent upon reaching a certain physiological stage in their life cycle (Dubnau, 1999 ).
  2. 2. New genetic material can also be introduced into a bacterium by a bacteriophage that has replicated within a donor microorganism and packaged random DNA fragments (generalized transduction) or the DNA adjacent to the phage attachment site (specialized transduction). The amount of DNA that can be transferred in a single event is limited by the size of the phage capsid, but can range upwards of 100 kb (Jiang & Paul, 1998 ; Schicklmaier & Schmieger, 1995

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  Advanced Molecular Biology

  A Concise Reference

  • Richard Twyman(Author)
  • 2018(Publication Date)
  • Garland Science

    (Publisher)

  Chapter 10

  Gene Transfer in Bacteria

  Fundamental concepts and definitions

  • Gene transfer describes the introduction of genetic information into a cell from an exogenous source (ultimately, another cell). This process occurs naturally in both bacteria and eukaryotes, and may be termed horizontal or lateral genetic transmission to distinguish it from the transmission of genetic information from parent to offspring, which is vertical genetic transmission.
  • Intraspecific gene transfer facilitates genetic mixing in asexual species and thus mimics the effects of sexual reproduction. Such parasexual exchange mechanisms have been exploited to map prokaryote genomes analogously to meiotic mapping (q.v.) in eukaryotes. Interspecific gene transfer can also occur, and is a natural mechanism of transgenesis (q.v.). Interspecific gene transfer is an important evolutionary process and has been responsible for some of the most fundamental evolutionary events (e.g. the endosymbiont origin of eukaryotic organelles) as well as facilitating specific interactions between bacteria and eukaryotes (e.g. tumor-induction by Agrobacterium tumorfaciens; q.v. Ti plasmid).
  • The source of the transferred information is the donor and the genetic information transferred is the exogenote (exogenous genome, usually only a fragment of the donor genome). The target of the gene transfer, the recipient, possesses the endogenote (endogenous genome). If the exogenote is homologous to part of the endogenote, gene transfer will make the recipient cell partially diploid (a merozygote), in which case recombination can occur, which may involve allele replacement (marker exchange).
  • There are four major mechanisms of gene transfer in bacteria: cell fusion, conjugation, transformation and transduction (Table 10.1 ).

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  Bacterial Pathogenesis

  A Molecular Approach

  • Brenda A. Wilson, Malcolm Winkler, Brian T. Ho, Brenda A. Wilson, Malcolm Winkler(Authors)
  • 2019(Publication Date)
  • ASM Press

    (Publisher)

  magine kissing someone and acquiring from that person a whole new chromosome, which gives you features of the person you kissed. Sound like a far-fetched science fiction scenario? For humans it is, but it is actually quite commonplace among microbes. Bacteria routinely undergo a process called conjugation, in which two bacterial cells engage in close contact with each other as one transfers segments of DNA into the other. These DNA segments can be extremely large, even hundreds of kilobases, accounting for as much as one-third of some bacterial chromosomes. Of course, the DNA segments that are typically transferred are much smaller than this, but most still carry multiple genes. This process is one of a group of processes collectively referred to as Horizontal Gene Transfer. Incredibly enough, most of the time, these large additions of DNA are well tolerated and can grant the bacteria powerful new traits such as resistance to antibiotics, the ability to utilize new nutrient sources, or new abilities to cause disease. Additionally, many of these bacterial gene transfers occur across species and genus lines. It might be pure science fiction when Peter Parker became Spiderman after being bitten by a spider, but that is essentially what happens all the time in the bacterial world.

  Adapt or Perish Acquiring New Virulence Traits by Horizontal Gene Transfer

  The ability of a bacterium to respond to new selective pressures, to survive adverse environmental conditions, or to exploit new environments that it encounters depends on its ability to evolve through modification of gene function via mutation or acquisition of new genes through Horizontal Gene Transfer (HGT) . Until recently, it was thought that changes to a microbe’s virulence properties would arise by slow processes involving point mutations, gene duplications, gene deletions, or chromosomal rearrangements, and that adaptive changes would occur largely through antigenic or phase variation (Table 7-1

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  Computational Methods For Understanding Bacterial And Archaeal Genomes

  • Ying Xu, Johann Peter Gogarten(Authors)
  • 2008(Publication Date)
  • ICP

    (Publisher)

  CHAPTER 6 Horizontal Gene Transfer: ITS DETECTION AND ROLE IN MICROBIAL EVOLUTION J. PETER GOGARTEN and OLGA ZHAXYBAYEVA 1. Introduction 1.1. The Early History of Gene Transfer Gene transfer played a crucial role at the birth of molecular biology: Using killed pathogenic Pneumococci Griffith was able to transform non pathogenic Pneumococcus strains into pathogens (Griffith, 1928). The same approach with additional treatments of the killed pathogens later was used to demonstrate that DNA is the transforming factor (Avery et al. , 1944). Gene transfer between prokaryotic organisms became an intense focus of interest, when it was recognized that bacteria can acquire antibiotic resistance genes not only from members of the same species, but also from only distantly related organisms (Gray and Fitch, 1983; Trieu-Cuot et al. , 1985). The ability to share genetic information and the absence of a clear barrier towards gene flow even led to the suggestion that all bacteria could be considered as a single species (Margulis and Sagan, 2002); or, as suggested by Sonea (1988b), could be seen as a single super organism: “all bacteria on Earth contribute to and draw benefits from, a common gene pool, which constitutes the communication network of a single super-organism whose continually shifting components are dispersed across the surface of the planet.” 1.2. Towards a Natural Taxonomy Traditionally, single celled organisms without a nucleus were placed into a group called monera (Haeckel, 1866) or prokaryotes (Stanier and Van Niel, 1962). Classification of single celled organisms within this group was initially based on morphology (e.g., cell shape), physiology and biochemistry (e.g., fermentation type and temperature ranges for growth) (for further discussion see Rossello-Mora and Amann (2001), Olendzenski et al.

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  Phylogenetics

  • Ibrokhim Y. Abdurakhmonov(Author)
  • 2017(Publication Date)
  • IntechOpen

    (Publisher)

  Here, we present genetic and genomic evidence indicating the evolutionary importance of reticulation in multicellular eukaryotes and summarize relevant reticulate issues and its bearings on phylogenetic practice. 2. Horizontal Gene Transfer (HGT) HGT phenomenon of genetic transference mainly among prokaryotes can occur via bacterial transformation, conjugation or transduction. It excludes mitosis and meiosis and does not require immediate ancestry. Bacterial genomes have revealed a complex evolutionary history, which cannot be represented by a single strictly bifurcating tree for most genes. Comparative analysis of sequenced genomes indicates that lineage-specific gene loss has been common in evolution, thus complicating the notion of a species tree, of a last universal common ancestor and the delimitation of its taxonomic units by being asexual. HGT in eukaryotes has been reported in phagotrophic protists and limited largely to the ancient acquisition of bacterial genes. Nevertheless, standard mitochondrial genes, encoding ribosomal and respiratory proteins, are subject to evolutionarily frequent horizontal transfer between distantly related flowering plants. These transfers have created a variety of genomic outcomes, including gene duplication, recapture of gene lost through transfer to the nucleus and chimeric, half-monocot, half-dicot genes [9]. As a result, from intergenomic comparisons, HGT appears as a dominant process to generate innovations and complex adaptations like the acquisition of shade-dwelling habits in ferns. Molecular evidence indicates that the chimeric photoreceptor, neochrome, was acquired from hornworts, thereby optimizing phototropic responses [ 10 ]. HGT not only involve individ -ual genes but also whole chromosomes and even nuclear genomes by asexual means. In the fungi genus Fusarium , HGT was responsible for the acquisition of chromosomes that largely increased the organism pathogenicity [11].

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  Genetic Interactions Among Microorganisms in the Natural Environment

  • E.M.H. Wellington, J.D. van Elsas(Authors)
  • 2013(Publication Date)
  • Pergamon

    (Publisher)

  Genetic transfer of rDNA to natural populations of soil bacteria could increase ecological niches available to GEMs. It appears that the poten-tial for genetic transfer between bacteria of the same and other species and genera is much greater than had been suspected (Miller, 1988; Brokamp & Schmidt, 1990), but difficult to evaluate on the basis of present inadequate in situ data. 3.2. Evidence for distribution of microbial genes in natural environments Some information about horizontal transfer of microbial genes has been obtained by focussing on gene transfer in defined ecosystems (Levy & Marshall, 1988; Henschke & Schmidt, 1990). One of these is the intes-tinal tract of humans and animals in which major systems of genetic transfer in bacteria such as conjugation, transduction, transformation and 43 44 Methods for studying genetic interactions in terrestrial environments transposition have been recognised and analysed. Other data have been obtained by looking at the natural distribution of particular genes in the environments. Unfortunately, little is known about the fate of genetic traits and specific genes released by sewage disposal. A proportion of the bacteria in sewage carry traits for pathogenicity and drug resistance factors, but there are limits to these kind of transfer studies, which cannot be performed in the laboratory. Indirect evidence for microbial DNA flux arose from recent compara-tive studies about the origin and distribution of drug resistance genes in bacteria isolated from hospitals and antibiotic-producing soil micro-organisms such as Streptomyces spp. Comparison of relevant resistance genes revealed similar amino acid, and in some cases similar nucleotide, sequences in streptomycetes and R-factor-bound genes mediating resist-ance to different antibiotics (Chater et al., 1988; see also Chapter 2). These findings support the notion of Horizontal Gene Transfer in soil com-munities.

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  Thermophiles

  The Keys to the Molecular Evolution and the Origin of Life?

  • Juergen Wiegel, Adams W.W. Michael(Authors)
  • 1998(Publication Date)
  • CRC Press

    (Publisher)

  Consequently, if these different 'temperature variants' were present in the same vicinity and were constantly disintegrating and reforming, one can propose that some entities took up genetic information which enabled them to cope better with the new existing -either hotter or cooler -temperatures. This would represent an early form of horizontal 'gene' transfer. Assuming that life evolved on surfaces probably of iron-sulfur compounds such as pyrite (Wachtershliuser 1988, 1992; Chapter 4 of this book; Russell et al. Chapter 6 of this book), and thus a close proximity of adsorbed entities, this scenario becomes very likely. Indications for the occurrence of Horizontal Gene Transfer are increasing (Hilario and Gogarten, 1993; Gogarten, 1995; Gogarten et al., 1996, and further discussed in Chapter 10 of this book; Hensel et al., 1989). Thus, for the hypothesis put forward, the possibility that Horizontal Gene Transfer can occur is taken as a given. The transfer could have occurred during the early stages of emerging life forms discussed above or at later stages of fully developed present-day genes. In the future, the hypothesis presented and the explanation of Horizontal Gene Transfers may be substantiated or dis-proved as more genomes, including those from bacteria which exhibit biphasic Arrhenius graphs for growth, are fully sequenced and most of the genes in the genomes are func-tionally identified. At the present time only about half of the genes on studied genomes can be associated with known gene products. Thus far, with respect to the hypothesis presented here, the genome-level analysis is not particularly meaningful or conclusive. 11.2 Overview of bacteria with an extended temperature range for growth and a biphasic Arrhenius plot for growth Generally, pure cultures of microorganisms grow over a temperature span of25-30 ·c.

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