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Draft:Original research/Molecular genetics

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This guinea pig has gorgeous long hair and was a prize winner at the Puyallup, WA fair. Credit: Christine from Washington State, USA.

Molecular genetics, unlike transmission genetics, focuses on the molecular level, that is, on DNA, proteins, genes, chromosomes and the like. Molecular genetics does not care so much about the trait itself being transferred to offspring, but more so on how traits in general are transferred to offspring. How can chemical information locked within DNA be transformed into facial features or vocal ability in our children?

Of course, the genetic molecule is DNA, or Deoxyribonucleic acid. DNA is made up of phosphate groups, a deoxyribose sugar, and a nucleotide. There are four nucleotides in DNA: Adenine, Thymine, Cytosine, and Guanine. Adenine binds to Thymine with two hydrogen bonds and Cytosine binds to Guanine with three hydrogen bonds. There is another nucleotide base called Uracil that is only found in RNA, a similar but different molecule from DNA. The phosphate groups are negatively charged and form the backbone of the DNA molecule with the nucleotide bases forming the center. The molecule twists to the right in a clockwise fashion to form a double helix.

When DNA is replicated it is typically in this loose, unbound form. During mitosis or meiosis, the DNA is supercoiled and bunched together with proteins called histones. This is what typically forms what we know as chromosomes during metaphase.

Genetics

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This is an image of Bob, the guinea pig. Credit: selbst.

Genetics involves the expression, transmission, and variation of inherited characteristics.

Def. a "branch of biology that deals with the transmission and variation of inherited characteristics,[1] in particular chromosomes and DNA"[2] is called genetics.

Molecules

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Main resources: Chemicals/Molecules and Molecules
These diagrams show the structure of the cafeine molecule. Credit: Effeietsanders.

Def. the "smallest particle of a specific element or compound [that retains the chemical properties of that element or compound]; a group of atoms held together by chemical bonds"[3] is called a molecule.

Molecular genetics is the field of biology that studies the structure and function of genes at a molecular level and thus employs methods of both molecular biology and genetics.[4]

Theoretical molecular genetics

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Def. a "field of biology which studies the structure and function of genes at a molecular level"[5] is called molecular genetics.

Amplification

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The main genetic components of the polymerase chain reaction (PCR) are DNA nucleotides, template DNA, primers and Taq polymerase; where DNA nucleotides make up the DNA template strand for the specific sequence being amplified and primers are short strands of complementary nucleotides where DNA replication starts and Taq polymerase is a heat stable enzyme that jump-starts the production of new DNA at the high temperatures needed for reaction.[6]

Cloning is the process of creating many identical copies of a sequence of DNA. The target DNA sequence is inserted into a cloning vector which originates from a self-replicating virus, plasmid, or higher organism cell, when the appropriate size DNA is inserted, the "target and vector DNA fragments are then ligated"[7] to create a recombinant DNA molecule.

The recombinant DNA molecule is then inserted into a bacterial strain (usually E. coli) which produces several identical copies of the selected sequence it absorbed through transformation (the mechanism by which bacteria uptake foreign DNA from the environment into their genomes)[8]

Detection

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DNA isolation extracts DNA from a cell in a pure form: first, the DNA is separated from cellular components such as proteins, RNA, and lipids by placing the chosen cells in a tube with a solution that mechanically, chemically, breaks the cells open except for the DNA; enzymes dissolve proteins, chemicals destroy all RNA present, and salts to help pull DNA out of the solution; second, the DNA is separated from the solution by being spun in a centrifuge, which allows the DNA to collect in the bottom of the tube; then the solution is poured off and the DNA is resuspended in a second solution that makes the DNA easy to work with in the future resulting in a concentrated DNA sample that contains thousands of copies of each gene,where for large scale projects such as full genome sequencing|sequencing the human genome, all this work is done by robots.[9]

Therapy

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Gene therapy can be used to replace a mutated gene with the correct copy of the gene, to inactivate or knockout the expression of a malfunctioning gene, or to introduce a foreign gene to the body to help fight disease.[10]

Major diseases that can be treated with gene therapy include viral infections, cancers, and inherited disorders, including immune system disorders.[11]

Gene therapy delivers a copy of the missing, mutated, or desired gene via a modified virus or vector to the patient's target cells so that a functional form of the protein can then be produced and incorporated into the body.[12] These vectors are often small interfering RNA (siRNA).[13] Treatment can be either in vivo or ex vivo. The therapy has to be repeated several times for the infected patient to continually be relieved, as repeated cell division and cell death slowly reduces the body's ratio of functional-to-mutant genes. Gene therapy is an appealing alternative to some drug-based approaches, because gene therapy repairs the underlying genetic defect using the patients own cells with minimal side effects.[13] Gene therapies are still in development and mostly used in research settings. All experiments and products are controlled by the Food and Drug Administration (U.S. FDA) and the National Institutes of Health (NIH).[14][15]

Hypotheses

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Main resource: Hypotheses
  1. Molecules that affect genetics should be enumerated.

See also

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References

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  1. ↑ SemperBlotto (6 November 2005). genetics. San Francisco, California: Wikimedia Foundation, Inc. https://en.wiktionary.org/wiki/genetics. Retrieved 2014-05-07. 
  2. ↑ 78.149.117.24 (22 December 2008). genetics. San Francisco, California: Wikimedia Foundation, Inc. https://en.wiktionary.org/wiki/genetics. Retrieved 2014-05-07. 
  3. ↑ SemperBlotto (12 January 2005). molecule. San Francisco, California: Wikimedia Foundation, Inc. https://en.wiktionary.org/wiki/molecule. Retrieved 2016-01-09. 
  4. ↑ Molecular Genetics (Stanford Encyclopedia of Philosophy). https://plato.stanford.edu/entries/molecular-genetics/. 
  5. ↑ Pumpie (27 August 2005). molecular genetics. San Francisco, California: Wikimedia Foundation, Inc. https://en.wiktionary.org/wiki/molecular_genetics. Retrieved 2016-01-09. 
  6. ↑ Ramsden, Jeremy J (2009). Bioinformatics: An Introduction. New York: Springer. p. 191. ISBN 978-1-84800-256-2. 
  7. ↑ NCBI
  8. ↑ Alberts, Bruce (2014). Essential Cell Biology (4th ed.). Garland Science. pp. 332-333. ISBN 978-0-8153-4454-4. 
  9. ↑ DNA isolation methods. March 18, 2015. https://web.archive.org/web/20150318222328/http://www.usfca.edu/fac-staff/dever/DNA_isolation_methods.pdf. 
  10. ↑ Reference, Genetics Home. What is gene therapy?. http://ghr.nlm.nih.gov/handbook/therapy/genetherapy. 
  11. ↑ Search of: "gene therapy" - List Results - ClinicalTrials.gov. https://clinicaltrials.gov/search?term=%22gene%20therapy%22. 
  12. ↑ Berg, Jeremy M., John L. Tymoczko, and Lubert Stryer. "Chapter 5: Exploring Genes and Genomes." Biochemistry. 7th ed. New York City: W.H. Freeman, 2012. N. pag. Print.
  13. ↑ 13.0 13.1 Herrera-Carrillo E, Berkhout B. Bone Marrow Gene Therapy for HIV/AIDS. Viruses 2015;7(7):3910-36.
  14. ↑ Reference, Genetics Home. Is gene therapy available to treat my disorder?. http://ghr.nlm.nih.gov/handbook/therapy/availability. 
  15. ↑ Reference, Genetics Home. Is gene therapy safe?. http://ghr.nlm.nih.gov/handbook/therapy/safety. 
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