Horizontal Gene Transfer in Microbial
Ecosystems
12
Ce ´line Brochier-Armanet and David Moreira
Abstract
Microorganisms live in fluctuating environments. At the microscopic scale, their habitats
are contrasted and have highly variable physical, chemical, and biological parameters. The
versatility of microbial ecosystems implies that microorganisms must constantly adapt to
these. Adaptation can result from spontaneous point mutations of the genetic material that
creates genetic diversity at the population level. However, this mechanism by itself is not
capable of explaining the extraordinary adaptive capacity of microorganisms. Research
performed in the first part of the twentieth century has revealed that this capacity results
very often from the ability to import genetic material from other microorganisms. This
phenomenon is called horizontal (or lateral) gene transfer (HGT). The mechanisms of
HGTs and their evolutionary consequences are discussed.
Keywords
Adaptation Archaea Bacteria Bioinformatics Conjugation Eukaryotes Evolution
Genome evolution Phylogeny Transformation Transduction
12.1 Introduction
Microorganisms live in fluctuating environments. At the
microscopic scale, their habitats are contrasted and highly
variable in their physical, chemical, and biological conditions.
The versatility of microbial ecosystems implies that
microorganisms must constantly adapt to them. Adaptation
can result from spontaneous point mutations of the genetic
material that create genetic diversity at the population level.
However, this mechanism by itself is not capable of explaining
the extraordinary adaptive capacity of microorganisms.
Research performed in the first part of the twentieth century
has revealed that this capacity results very often from the
ability to import genetic material from other microorganisms.
This phenomenon is called horizontal (or lateral) gene transfer
(HGT). The mechanisms of HGTs and their evolutionary
consequences will be discussed in this chapter.
12.2 Mechanisms of Horizontal Gene
Transfer
12.2.1 DNA Acquisition Through Horizontal
Gene Transfer
12.2.1.1 Transformation
Transformation is the mechanism by which naked DNA
present in the environment penetrates into cells, which are
called receptor cells (for additional information, see Chen
and Dubnau 2004; Thomas and Nielsen 2005). This capacity
is very important for microorganisms because DNA can be a
source of nutrients (i.e., phosphorus, carbon, nitrogen) for
C. Brochier-Armanet* (*)
Laboratoire de Biome ´trie et Biologie E ´ volutive, UMR CNRS 5558,
Universite ´ Claude Bernard Lyon 1, 69622 Villeurbanne Cedex, France
e-mail: celine.brochier-armanet@univ-lyon1.fr
D. Moreira
Unite ´ d’E ´ cologie, Syste ´matique et E ´ volution, UMR CNRS 8079,
Universite ´ Paris-Sud, 91405 Orsay Cedex, France
* Chapter Coordinator
J.-C. Bertrand et al. (eds.), Environmental Microbiology: Fundamentals and Applications: Microbial Ecology,
DOI 10.1007/978-94-017-9118-2_12, # Springer Science+Business Media Dordrecht 2015
445
Ecosystems
12
Ce ´line Brochier-Armanet and David Moreira
Abstract
Microorganisms live in fluctuating environments. At the microscopic scale, their habitats
are contrasted and have highly variable physical, chemical, and biological parameters. The
versatility of microbial ecosystems implies that microorganisms must constantly adapt to
these. Adaptation can result from spontaneous point mutations of the genetic material that
creates genetic diversity at the population level. However, this mechanism by itself is not
capable of explaining the extraordinary adaptive capacity of microorganisms. Research
performed in the first part of the twentieth century has revealed that this capacity results
very often from the ability to import genetic material from other microorganisms. This
phenomenon is called horizontal (or lateral) gene transfer (HGT). The mechanisms of
HGTs and their evolutionary consequences are discussed.
Keywords
Adaptation Archaea Bacteria Bioinformatics Conjugation Eukaryotes Evolution
Genome evolution Phylogeny Transformation Transduction
12.1 Introduction
Microorganisms live in fluctuating environments. At the
microscopic scale, their habitats are contrasted and highly
variable in their physical, chemical, and biological conditions.
The versatility of microbial ecosystems implies that
microorganisms must constantly adapt to them. Adaptation
can result from spontaneous point mutations of the genetic
material that create genetic diversity at the population level.
However, this mechanism by itself is not capable of explaining
the extraordinary adaptive capacity of microorganisms.
Research performed in the first part of the twentieth century
has revealed that this capacity results very often from the
ability to import genetic material from other microorganisms.
This phenomenon is called horizontal (or lateral) gene transfer
(HGT). The mechanisms of HGTs and their evolutionary
consequences will be discussed in this chapter.
12.2 Mechanisms of Horizontal Gene
Transfer
12.2.1 DNA Acquisition Through Horizontal
Gene Transfer
12.2.1.1 Transformation
Transformation is the mechanism by which naked DNA
present in the environment penetrates into cells, which are
called receptor cells (for additional information, see Chen
and Dubnau 2004; Thomas and Nielsen 2005). This capacity
is very important for microorganisms because DNA can be a
source of nutrients (i.e., phosphorus, carbon, nitrogen) for
C. Brochier-Armanet* (*)
Laboratoire de Biome ´trie et Biologie E ´ volutive, UMR CNRS 5558,
Universite ´ Claude Bernard Lyon 1, 69622 Villeurbanne Cedex, France
e-mail: celine.brochier-armanet@univ-lyon1.fr
D. Moreira
Unite ´ d’E ´ cologie, Syste ´matique et E ´ volution, UMR CNRS 8079,
Universite ´ Paris-Sud, 91405 Orsay Cedex, France
* Chapter Coordinator
J.-C. Bertrand et al. (eds.), Environmental Microbiology: Fundamentals and Applications: Microbial Ecology,
DOI 10.1007/978-94-017-9118-2_12, # Springer Science+Business Media Dordrecht 2015
445