DNA

DNA

Molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses.

Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids; alongside proteins, lipids and complex carbohydrates (polysaccharides), nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life. The two DNA strands are also known as polynucleotides as they are composed of simpler monomeric units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases (cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules (A with T and C with G), with hydrogen bonds to make double-stranded DNA. The complementary nitrogenous bases are divided into two groups, pyrimidines and purines. In DNA, the pyrimidines are thymine and cytosine; the purines are adenine and guanine. Both strands of double-stranded DNA store the same biological information. This information is replicated as and when the two strands separate.

A large part of DNA (more than 98% for humans) is non-coding, meaning that these sections do not serve as patterns for protein sequences. The two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases (informally, bases). It is the sequence of these four nucleobases along the backbone that encodes genetic information. RNA strands are created using DNA strands as a template in a process called transcription. Under the genetic code, these RNA strands specify the sequence of amino acids within proteins in a process called translation. Within eukaryotic cells, DNA is organized into long structures called chromosomes. Before typical cell division, these chromosomes are duplicated in the process of DNA replication, providing a complete set of chromosomes for each daughter cell. Eukaryotic organisms (animals, plants, fungi and protists) store most of their DNA inside the cell nucleus as nuclear DNA, and some in the mitochondria as mitochondrial DNA, or in chloroplasts as chloroplast DNA. In contrast, prokaryotes (bacteria and archaea) store their DNA only in the cytoplasm, in circular chromosomes. Within eukaryotic chromosomes, chromatin proteins, such as histones, compact and organize DNA. These compacting structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.

DNA was first isolated by Friedrich Miescher in 1869. Its molecular structure was first identified by Francis Crick and James Watson at the Cavendish Laboratory within the University of Cambridge in 1953, whose model-building efforts were guided by X-ray diffraction data acquired by Raymond Gosling, who was a post-graduate student of Rosalind Franklin. DNA is used by researchers as a molecular tool to explore physical laws and theories, such as the ergodic theorem and the theory of elasticity. The unique material properties of DNA have made it an attractive molecule for material scientists and engineers interested in micro- and nano-fabrication. Among notable advances in this field are DNA origami and DNA-based hybrid materials.

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May 27, 2020
BioSpace
Triplet Therapeutics Initiates SHIELD HD Natural History Study of Huntington's Disease - read this article along with other careers information, tips and advice on BioSpace
BioSpace
May 27, 2020
BioSpace
An early age of pregnancy is known to reduce the overall risk of breast cancer by over 30%. CSHL Assistant Professor Camila dos Santos spent several years teasing out the molecular details behind the protective effects of pregnancy.
Nicole Wetsman
May 22, 2020
The Verge
Vaccine developers have four major strategies in their efforts to make a coronavirus vaccine: gene-based, adenovirus vectors, inactivated, and protein subunit. All have pros and cons, both around how they provide protection from a virus and how they're manufactured.
Mark Terry
May 22, 2020
BioSpace
Every week there are numerous scientific studies published. Here's a look at some of the more interesting ones.
Arlene Weintraub
May 21, 2020
FierceBiotech
Two animal studies out of Harvard showed DNA vaccines against COVID-19 generated similar levels of antibodies that can neutralize the virus as the actual infection does. That will likely fuel enthusiasm for efforts to rapidly develop vaccines against the disease, though the researchers warned there are still several unanswered questions.
BioSpace
May 20, 2020
BioSpace
Publication in Nature Communications demonstrates generation of robust neutralizing antibodies and T cell responses against SARS-CoV-2
By Michael Thomsen For Dailymail.com
May 19, 2020
Mail Online
A new joint study from MIT and Harvard has identified an enzyme that could help reverse the effects of DNA damage associated with aging and Alzheimer's disease, based on testing in mice.
May 18, 2020
@TIMESNOW
More than 100 COVID-19 vaccine candidates are in various stages of development with a handful of them already in early human trials. Three coronavirus vaccines have entered phase 2 clinical trials.
May 15, 2020
WebWire
Wisdom Health Genetics, the world's leader in pet genetics and makers of the Wisdom PanelTM dog DNA tests, announced the launch of two new and improved dog DNA tests: the Wisdom PanelTM Essential test and the Wisdom PanelTM Premium test. The Wisdom PanelTM Essential test is geared toward pet parents who have recently adopted a puppy or a new to you dog, offering breed, traits and 25+ actionable health tests, providing information to help you and your veterinarian manage your dog's medic...
Ifeoma Ajunwa
May 13, 2020
Scientific American Blog Network
We shouldn't risk our genetic privacy to find it
Brooke Jarvis
May 13, 2020
Wired
The very first vaccine candidate entered human trials--and Neal Browning's arm--on March 16. Behind the scenes at Moderna and the beginning of an unprecedented global sprint.
Gail Dutton
May 11, 2020
BioSpace
A smartphone diagnostic test for COVID-19 being developed by a University of Utah researcher holds the potential for quick, accurate testing without the need for individuals to go to a healthcare facility. A prototype may be ready within two to three months.
Kiona N. Smith
May 6, 2020
Ars Technica
They are among the earliest enslaved African people brought to the Americas.
Dana P. Goldman
May 6, 2020
Scientific American Blog Network
Blood tests that find malignancies before they spread could transform our approach to treatment
Beth Mole
May 1, 2020
Ars Technica
Here's where we are and what may lie ahead for a vaccine against COVID-19.
Layal Liverpool
April 30, 2020
New Scientist
The remains of three slaves found in Mexico contain the earliest signs of the hepatitis B virus and yaws bacteria in the Americas, suggesting transatlantic slavery introduced these diseases
By Joe Pinkstone For Mailonline
April 28, 2020
Mail Online
German researchers observed mice exposed to loud noises, such as those from a passing aircraft. Four days of aircraft noise led to high blood pressure.
April 24, 2020
clinicaltrials.gov
COVID-19 Recovered Volunteer Research Participant Pool Registry - Full Text View.
April 24, 2020
clinicaltrials.gov
Ivermectin and Nitazoxanide Combination Therapy for COVID-19 - Full Text View.
By Joe Pinkstone For Mailonline
April 23, 2020
Mail Online
Data from the European Space Agency Sentinel-2 satellites was used to detect patches of floating macroplastics larger than five millimetres (0.2 inches) in marine environments.
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