Genetic ecology

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Genetic ecology is the study of the stability and expression of varying genetic material within abiotic mediums. [1] Typically, genetic data is not thought of outside of any organism save for criminal forensics. However, genetic material has the ability to be taken up by various organisms that exist within an abiotic medium through natural transformations that may occur. [2] Thus, this field of study focuses on interaction, exchange, and expression of genetic material that may not be shared by species had they not been in the same environment.

Contents

History

E.B. Ford was the first geneticist to begin work in this field of study. E.B. Ford worked mostly during the 1950s and is most noted for his work with Maniola jurtina and published a book entitled Ecological Genetics in 1975. [3] [4] This type of evolutionary biological study was only possible after gel electrophoresis had been designed in 1937. [5] Prior to this, a high throughput method for DNA analysis did not exist. This field of study began to become more popular following the 1980s with the development of polymerase chain reaction (PCR 1985) and poly-acrylamide gel electrophoresis (p. 1967). [6] [7] With this technology, segments of DNA could be sequenced, amplified, and proteins produced using bacterial transformations. The genetic material along with the proteins could be analyzed and more correct phylogenetic trees could be created.

Since E.B. Ford's research, multiple other genetic ecologists have continued study within the field of genetic ecology such as PT Hanford [8] Alina von Thaden, [9] and many others. [10] [11] [12] [13] [14]

Gene transfer

Genetic information may transfer throughout an ecosystem in multiple ways. The first of which, on the smallest scale, being bacterial gene transfer (see bacterial transformations). Bacteria have the ability to exchange DNA. This DNA exchange, or horizontal gene transfer, may provide various species of bacteria with the genetic information they need to survive in an environment. [15] This can help many bacterial species survive within an environment.

A similar event has the ability to happen between plants and bacteria. For example, Agrobacterium tumefaciens has the ability to introduce genes into plants to cause the development of Gall disease. This occurs through genetic transfer between the A. tumefaciens and between the plant in question. [16]

In fact, a similar event occurs each time viral infections occur within living organisms. The viruses, whether positive or negative sense viruses, require a living organism to replicate their genes and produce more viruses. Once a virus is inside a living organism, it utilizes polymerases, ribosomes, and other biomolecules to replicate its own genetic material and to produce more virus genetic material similar to the original virus. [17] Thus, gene transfer may occur through many varying means. Thus, the study of this gene transfer throughout each ecosystem, whether it be through a bacterial ecosystem or through the ecosystem of an organism, genetic ecology is the study of this gene transfer and its causes.

See also

Related Research Articles

<span class="mw-page-title-main">Outline of biology</span> Outline of subdisciplines within biology

Biology – The natural science that studies life. Areas of focus include structure, function, growth, origin, evolution, distribution, and taxonomy.

Molecular biology is a branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions.

<span class="mw-page-title-main">Plasmid</span> Small DNA molecule within a cell

A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; however, plasmids are sometimes present in archaea and eukaryotic organisms. In nature, plasmids often carry genes that benefit the survival of the organism and confer selective advantage such as antibiotic resistance. While chromosomes are large and contain all the essential genetic information for living under normal conditions, plasmids are usually very small and contain only additional genes that may be useful in certain situations or conditions. Artificial plasmids are widely used as vectors in molecular cloning, serving to drive the replication of recombinant DNA sequences within host organisms. In the laboratory, plasmids may be introduced into a cell via transformation. Synthetic plasmids are available for procurement over the internet.

<span class="mw-page-title-main">Horizontal gene transfer</span> Type of nonhereditary genetic change

Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). HGT is an important factor in the evolution of many organisms. HGT is influencing scientific understanding of higher order evolution while more significantly shifting perspectives on bacterial evolution.

The restriction modification system is found in bacteria and other prokaryotic organisms, and provides a defense against foreign DNA, such as that borne by bacteriophages.

<span class="mw-page-title-main">Molecular genetics</span> Scientific study of genes at the molecular level

Molecular genetics is a branch of biology that addresses how differences in the structures or expression of DNA molecules manifests as variation among organisms. Molecular genetics often applies an "investigative approach" to determine the structure and/or function of genes in an organism's genome using genetic screens. 

Ecological genetics is the study of genetics in natural populations. Traits in a population can be observed and quantified to represent a species adapting to a changing environment.

<span class="mw-page-title-main">Transformation (genetics)</span> Genetic alteration of a cell by uptake of genetic material from the environment

In molecular biology and genetics, transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s). For transformation to take place, the recipient bacterium must be in a state of competence, which might occur in nature as a time-limited response to environmental conditions such as starvation and cell density, and may also be induced in a laboratory.

<i>Agrobacterium tumefaciens</i> Bacterium, genetic engineering tool

Agrobacterium tumefaciens is the causal agent of crown gall disease in over 140 species of eudicots. It is a rod-shaped, Gram-negative soil bacterium. Symptoms are caused by the insertion of a small segment of DNA, from a plasmid into the plant cell, which is incorporated at a semi-random location into the plant genome. Plant genomes can be engineered by use of Agrobacterium for the delivery of sequences hosted in T-DNA binary vectors.

<span class="mw-page-title-main">Transduction (genetics)</span> Transfer process in genetics

Transduction is the process by which foreign DNA is introduced into a cell by a virus or viral vector. An example is the viral transfer of DNA from one bacterium to another and hence an example of horizontal gene transfer. Transduction does not require physical contact between the cell donating the DNA and the cell receiving the DNA, and it is DNase resistant. Transduction is a common tool used by molecular biologists to stably introduce a foreign gene into a host cell's genome.

Microbial genetics is a subject area within microbiology and genetic engineering. Microbial genetics studies microorganisms for different purposes. The microorganisms that are observed are bacteria, and archaea. Some fungi and protozoa are also subjects used to study in this field. The studies of microorganisms involve studies of genotype and expression system. Genotypes are the inherited compositions of an organism. Genetic Engineering is a field of work and study within microbial genetics. The usage of recombinant DNA technology is a process of this work. The process involves creating recombinant DNA molecules through manipulating a DNA sequence. That DNA created is then in contact with a host organism. Cloning is also an example of genetic engineering.

Bacteriophages (phages), potentially the most numerous "organisms" on Earth, are the viruses of bacteria. Phage ecology is the study of the interaction of bacteriophages with their environments.

<span class="mw-page-title-main">Gene delivery</span> Introduction of foreign genetic material into host cells

Gene delivery is the process of introducing foreign genetic material, such as DNA or RNA, into host cells. Gene delivery must reach the genome of the host cell to induce gene expression. Successful gene delivery requires the foreign gene delivery to remain stable within the host cell and can either integrate into the genome or replicate independently of it. This requires foreign DNA to be synthesized as part of a vector, which is designed to enter the desired host cell and deliver the transgene to that cell's genome. Vectors utilized as the method for gene delivery can be divided into two categories, recombinant viruses and synthetic vectors.

The following outline is provided as an overview of and topical guide to genetics:

<span class="mw-page-title-main">Avery–MacLeod–McCarty experiment</span> 1944 microbiology experiment

The Avery–MacLeod–McCarty experiment was an experimental demonstration by Oswald Avery, Colin MacLeod, and Maclyn McCarty that, in 1944, reported that DNA is the substance that causes bacterial transformation, in an era when it had been widely believed that it was proteins that served the function of carrying genetic information. It was the culmination of research in the 1930s and early 20th century at the Rockefeller Institute for Medical Research to purify and characterize the "transforming principle" responsible for the transformation phenomenon first described in Griffith's experiment of 1928: killed Streptococcus pneumoniae of the virulent strain type III-S, when injected along with living but non-virulent type II-R pneumococci, resulted in a deadly infection of type III-S pneumococci. In their paper "Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types: Induction of Transformation by a Desoxyribonucleic Acid Fraction Isolated from Pneumococcus Type III", published in the February 1944 issue of the Journal of Experimental Medicine, Avery and his colleagues suggest that DNA, rather than protein as widely believed at the time, may be the hereditary material of bacteria, and could be analogous to genes and/or viruses in higher organisms.

Bacterial genetics is the subfield of genetics devoted to the study of bacterial genes. Bacterial genetics are subtly different from eukaryotic genetics, however bacteria still serve as a good model for animal genetic studies. One of the major distinctions between bacterial and eukaryotic genetics stems from the bacteria's lack of membrane-bound organelles, necessitating protein synthesis occur in the cytoplasm.

Bacterial genomes are generally smaller and less variant in size among species when compared with genomes of eukaryotes. Bacterial genomes can range in size anywhere from about 130 kbp to over 14 Mbp. A study that included, but was not limited to, 478 bacterial genomes, concluded that as genome size increases, the number of genes increases at a disproportionately slower rate in eukaryotes than in non-eukaryotes. Thus, the proportion of non-coding DNA goes up with genome size more quickly in non-bacteria than in bacteria. This is consistent with the fact that most eukaryotic nuclear DNA is non-gene coding, while the majority of prokaryotic, viral, and organellar genes are coding. Right now, we have genome sequences from 50 different bacterial phyla and 11 different archaeal phyla. Second-generation sequencing has yielded many draft genomes ; third-generation sequencing might eventually yield a complete genome in a few hours. The genome sequences reveal much diversity in bacteria. Analysis of over 2000 Escherichia coli genomes reveals an E. coli core genome of about 3100 gene families and a total of about 89,000 different gene families. Genome sequences show that parasitic bacteria have 500–1200 genes, free-living bacteria have 1500–7500 genes, and archaea have 1500–2700 genes. A striking discovery by Cole et al. described massive amounts of gene decay when comparing Leprosy bacillus to ancestral bacteria. Studies have since shown that several bacteria have smaller genome sizes than their ancestors did. Over the years, researchers have proposed several theories to explain the general trend of bacterial genome decay and the relatively small size of bacterial genomes. Compelling evidence indicates that the apparent degradation of bacterial genomes is owed to a deletional bias.

<span class="mw-page-title-main">History of genetic engineering</span>

Genetic engineering is the science of manipulating genetic material of an organism. The first artificial genetic modification accomplished using biotechnology was transgenesis, the process of transferring genes from one organism to another, first accomplished by Herbert Boyer and Stanley Cohen in 1973. It was the result of a series of advancements in techniques that allowed the direct modification of the genome. Important advances included the discovery of restriction enzymes and DNA ligases, the ability to design plasmids and technologies like polymerase chain reaction and sequencing. Transformation of the DNA into a host organism was accomplished with the invention of biolistics, Agrobacterium-mediated recombination and microinjection. The first genetically modified animal was a mouse created in 1974 by Rudolf Jaenisch. In 1976 the technology was commercialised, with the advent of genetically modified bacteria that produced somatostatin, followed by insulin in 1978. In 1983 an antibiotic resistant gene was inserted into tobacco, leading to the first genetically engineered plant. Advances followed that allowed scientists to manipulate and add genes to a variety of different organisms and induce a range of different effects. Plants were first commercialized with virus resistant tobacco released in China in 1992. The first genetically modified food was the Flavr Savr tomato marketed in 1994. By 2010, 29 countries had planted commercialized biotech crops. In 2000 a paper published in Science introduced golden rice, the first food developed with increased nutrient value.

<span class="mw-page-title-main">Genetic engineering techniques</span> Methods used to change the DNA of organisms

Genetic engineering techniques allow the modification of animal and plant genomes. Techniques have been devised to insert, delete, and modify DNA at multiple levels, ranging from a specific base pair in a specific gene to entire genes. There are a number of steps that are followed before a genetically modified organism (GMO) is created. Genetic engineers must first choose what gene they wish to insert, modify, or delete. The gene must then be isolated and incorporated, along with other genetic elements, into a suitable vector. This vector is then used to insert the gene into the host genome, creating a transgenic or edited organism.

Bacterial recombination is a type of genetic recombination in bacteria characterized by DNA transfer from one organism called donor to another organism as recipient. This process occurs in three main ways:

References

  1. ↑ Kellenberger, E. (15 May 1994) "Genetic ecology: a new interdisciplinary science, fundamental for evolution, biodiversity and biosafety evaluations" Experientia vol50:5 pp. 429–437
  2. ↑ Lederberg, J. (1994) The Transformation of Genetics The Rockefeller University, New York, New York
  3. ↑ Ecological Genetics (n.d.)
  4. ↑ Baxter S.W. et al. (2017) "EB Ford revisited: assessing the long-term stability of wing-spot patterns and population genetic structure of the meadow brown butterfly on the Isles of Scilly" Heredity
  5. ↑ Tiselius, A. (25 January 1937) "A New Apparatus for Electrophoretic Analysis of Colloidal Mixtures" Transactions of the Faraday Society
  6. ↑ Shapiro, A.L. et al. (7 September 1967) "Molecular weight estimation of polypeptide chains by electrophoresis in SDS-polyacrylamide gels" Biochem Biophys Res Commun
  7. ↑ "The History of PCR" Archived 2011-03-13 at the Wayback Machine (2004)
  8. ↑ Handford PT. (1973) "Patterns of variation in a number of genetic systems in Maniola jurtina" Isles of Scilly. Proc R Soc B Biol Sci 183: 285–300. |
  9. ↑ Thaden, A. et al. (11 August 2017) "Assessing SNP genotyping of noninvasively collected wildlife samples using microfluidic arrays" Scientific Reports
  10. ↑ Frachon, L et al. (27 July 2017) "Intermediate degrees of synergistic pleiotropy drive adaptive evolution in ecological time" Nature, Ecology, and Evolution
  11. ↑ Torda, G. et al. (26 July 2017) Rapid adaptive responses to climate change in corals Nature Climate Change
  12. ↑ Benvenuto, C. Cosica, I. Chopelet, J. Sala-Bozano, M. Mariani, S. (25 July 2017) Ecological and evolutionary consequences of alternative sex-change pathways in fish Scientific Reports
  13. ↑ Cure, K. Thomas, L. Hobbs, JPA. Fairclough, D.V. Kennington, W.J. (25 July 2017) "Genomic signatures of local adaptation reveal source-sink dynamics in a high gene flow fish species" Scientific Reports
  14. ↑ Komurai, R. Fujisawa, T. Okuzaki, Y. Sota, T. (11 July 2017) "Genomic regions and genes related to inter-population differences in body size in the ground beetle Carabus japonicus" Scientific Reports
  15. ↑ "Horizontal Gene Transfer" Archived 2017-09-28 at the Wayback Machine . (n.d.).
  16. ↑ "Methods of Gene Transfer in Plants" (2011) Agricultural Biosecurity
  17. ↑ 7. Weaver, R. (2012). Molecular biology (5th ed.). New York: McGraw-Hill
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