Instruct: Given a question, retrieve relevant passages that answer the question.
Query: Who discovered mitochondrial DNA?
The cytosolic, intermembrane space, compartment has a water content of 3.8 μl/mg protein, while the mitochondrial matrix 0.8 μl/mg protein. It is not known how mitochondria maintain osmotic balance across the inner mitochondrial membrane, although the membrane contains aquaporins that are believed to be conduits for regulated water transport. Mitochondrial matrix has a pH of about 7.8. Mitochondrial DNA was discovered by Nash and Margit in 1963. One to many double stranded mainly circular DNA is present in mitochondrial matrix. Mitochondrial DNA is 1% of total DNA of a cell. It is rich in Guanine and Cytosine content. Mitochondria of mammals have 55s ribosomes.
In August 1961, at the International Congress of Biochemistry in Moscow, Nirenberg presented his paper. The experimentation with synthetic RNA in a cell-free system was a key technical innovation. In 1961, when they announced their methods for decoding the relationship of mRNA to amino acids, there was still a lot of experimentation required before the entire code was deciphered. The scientists had to determine which bases made up each codon, then determine the sequence of bases in the codons. This proved to be a tremendous amount of work.
The 2008 Nobel Prize in Physiology or Medicine was awarded to Montagnier and Françoise Barré-Sinoussi for the discovery of HIV. They shared the Prize with Harald zur Hausen, who discovered that human papilloma viruses can cause cervical cancer. Montagnier said he was "surprised" that Robert Gallo was not also recognized by the Nobel Committee: "It was important to prove that HIV was the cause of AIDS, and Gallo had a very important role in that. I'm very sorry for Robert Gallo." According to Maria Masucci, a member of the Nobel Assembly, "there was no doubt as to who made the fundamental discoveries."
Cell theory led biologists to re-envision individual organisms as interdependent assemblages of individual cells. Scientists in the rising field of cytology, armed with increasingly powerful microscopes and new staining methods, soon found that even single cells were far more complex than the homogeneous fluid-filled chambers described by earlier microscopists. Robert Brown had described the nucleus in 1831, and by the end of the 19th century cytologists identified many of the key cell components: chromosomes, centrosomes mitochondria, chloroplasts, and other structures made visible through staining. Between 1874 and 1884 Walther Flemming described the discrete stages of mitosis, showing that they were not artifacts of staining but occurred in living cells, and moreover, that chromosomes doubled in number just before the cell divided and a daughter cell was produced. Much of the research on cell reproduction came together in August Weismann's theory of heredity: he identified the nucleus (in particular chromosomes) as the hereditary material, proposed the distinction between somatic cells and germ cells (arguing that chromosome number must be halved for germ cells, a precursor to the concept of meiosis), and adopted Hugo de Vries's theory of pangenes. Weismannism was extremely influential, especially in the new field of experimental embryology.
The genus "Neisseria" is named after the German bacteriologist Albert Neisser, who in 1879 discovered its first example, "Neisseria gonorrheae", the pathogen which causes the human disease gonorrhea. Neisser also codiscovered the pathogen that causes leprosy, "Mycobacterium leprae". These discoveries were made possible by the development of new staining techniques which he helped to develop.
The field of oxidative phosphorylation began with the report in 1906 by Arthur Harden of a vital role for phosphate in cellular fermentation, but initially only sugar phosphates were known to be involved. However, in the early 1940s, the link between the oxidation of sugars and the generation of ATP was firmly established by Herman Kalckar, confirming the central role of ATP in energy transfer that had been proposed by Fritz Albert Lipmann in 1941. Later, in 1949, Morris Friedkin and Albert L. Lehninger proved that the coenzyme NADH linked metabolic pathways such as the citric acid cycle and the synthesis of ATP. The term "oxidative phosphorylation" was coined by in 1939.
The history of genetics dates from the classical era with contributions by Hippocrates, Aristotle and Epicurus. Modern biology began with the work of the Augustinian friar Gregor Johann Mendel. His work on pea plants, published in 1866,what is now Mendelian inheritance. Some theories of heredity suggest in the centuries before and for several decades after Mendel's work.
The year 1900 marked the "rediscovery of Mendel" by Hugo de Vries, Carl Correns and Erich von Tschermak, and by 1915 the basic principles of Mendelian genetics had been applied to a wide variety of organisms—most notably the fruit fly "Drosophila melanogaster". Led by Thomas Hunt Morgan and his fellow "drosophilists", geneticists developed the Mendelian model, which was widely accepted by 1925. Alongside experimental work, mathematicians developed the statistical framework of population genetics, bringing genetic explanations into the study of evolution.
Cell, developmental, and reproductive biology have been a central part of the MBL's programs since the 1890s. Important discoveries in these fields at the MBL reach back to 1899, when Jacques Loeb demonstrated artificial parthenogenesis in sea urchin eggs; to 1905, when Edwin Grant Conklin first identified egg cytoplasmic regions that are programmed to form certain tissues or organs; to 1916, when Frank Rattray Lillie identified circulating hormones that influence sexual differentiation (Lillie, 1944). In the MBL's first two decades, cytologists Edmund Beecher Wilson, Nettie Stevens and others made connections between the chromosomes and Mendelian heredity, while Wilson's colleague at both the MBL and Columbia University, Thomas Hunt Morgan, launched the field of experimental genetics (Pauly, 2000:158). Keith R. Porter, considered by many to be a founder of modern cell biology due to his pioneering work on the fine structure of cells, including the discovery of microtubules, carried out research at the MBL starting in 1937 and directed the laboratory from 1975-77 (Barlow et al., 1993: 95-115).
Another group working contemporaneously with the Montagnier and Gallo groups was that of Dr. Jay Levy at the University of California, San Francisco. He independently discovered the AIDS virus in 1983 and named it the AIDS associated retrovirus (ARV). This virus was very different from the virus reported by the Montagnier and Gallo groups. The ARV strains indicated, for the first time, the heterogeneity of HIV isolates and several of these remain classic examples of the AIDS virus found in the United States.
It was not until French President François Mitterrand and American President Ronald Reagan met in person that the major issues were ironed out. The scientific protagonists finally agreed to share credit for the discovery of HIV, and in 1986, both the French and the US names (LAV and HTLV-III) were dropped in favor of the new term "human immunodeficiency virus" (virus de l'immunodéficience humaine, abbreviated HIV or VIH) (Coffin, 1986). They concluded that the origin of the HIV-1 Lai/IIIB isolate discovered by Gallo was the same as that discovered by Montagnier (but not known by Montagnier to cause AIDS). This compromise allowed Montagnier and Gallo to end their feud and collaborate with each other again, writing a chronology that appeared in "Nature" that year.
The true identity of the discoverers of carbon nanotubes is a subject of some controversy. A 2006 editorial written by Marc Monthioux and Vladimir Kuznetsov in the journal "Carbon" described the interesting and often-misstated origin of the carbon nanotube. A large percentage of academic and popular literature attributes the discovery of hollow, nanometer-size tubes composed of graphitic carbon to Sumio Iijima of NEC in 1991. He published a paper describing his discovery which initiated a flurry of excitement and could be credited by inspiring the many scientists now studying applications of carbon nanotubes. Though Iijima has been given much of the credit for discovering carbon nanotubes, it turns out that the timeline of carbon nanotubes goes back much further than 1991.
The term "biochemistry" itself is derived from a combination of biology and chemistry. In 1877, Felix Hoppe-Seyler used the term ("biochemie" in German) as a synonym for physiological chemistry in the foreword to the first issue of "Zeitschrift für Physiologische Chemie" (Journal of Physiological Chemistry) where he argued for the setting up of institutes dedicated to this field of study. The German chemist Carl Neuberg however is often cited to have coined the word in 1903, while some credited it to Franz Hofmeister.
It was once generally believed that life and its materials had some essential property or substance (often referred to as the "vital principle") distinct from any found in non-living matter, and it was thought that only living beings could produce the molecules of life. Then, in 1828, Friedrich Wöhler published a paper on the synthesis of urea, proving that organic compounds can be created artificially. Since then, biochemistry has advanced, especially since the mid-20th century, with the development of new techniques such as chromatography, X-ray diffraction, dual polarisation interferometry, NMR spectroscopy, radioisotopic labeling, electron microscopy, and molecular dynamics simulations. These techniques allowed for the discovery and detailed analysis of many molecules and metabolic pathways of the cell, such as glycolysis and the Krebs cycle (citric acid cycle), and led to an understanding of biochemistry on a molecular level. Philip Randle is well-known for his discovery in diabetes research is possibly the glucose-fatty acid cycle in 1963.He confirmed that fatty acids reduce oxidation of sugar by the muscle. High fat oxidation was responsible for the insulin resistance.
The discovery of a role for the pancreas in diabetes is generally ascribed to Joseph von Mering and Oskar Minkowski, who in 1889 found that dogs whose pancreas was removed developed all the signs and symptoms of diabetes and died shortly afterwards. In 1910, Sir Edward Albert Sharpey-Schafer suggested that people with diabetes were deficient in a single chemical that was normally produced by the pancreas—he proposed calling this substance insulin, from the Latin "insula", meaning island, in reference to the insulin-producing islets of Langerhans in the pancreas. The endocrine role of the pancreas in metabolism, and indeed the existence of insulin, was further clarified in 1921, when Sir Frederick Grant Banting and Charles Herbert Best repeated the work of Von Mering and Minkowski, and went further to demonstrate they could reverse induced diabetes in dogs by giving them an extract from the pancreatic islets of Langerhans of healthy dogs. The islets of Langerhans was discovered in 1869 by an anatomist named Paul Langerhans. He identified the keys cells in the pancreas which produce the main substance that controls glucose levels in the body.
The name "autophagy" was coined by Belgian biochemist Christian de Duve in 1963 based on his discovery of the functions of lysosome. The identification of autophagy-related genes in yeast in the 1990s let researchers figure out the mechanisms of autophagy, which eventually led to the award of the 2016 Nobel Prize in Physiology or Medicine to Japanese researcher Yoshinori Ohsumi.
The discovery of carbon nanotubes is largely attributed to Sumio Iijima of NEC in 1991, although carbon nanotubes have been produced and observed under a variety of conditions prior to 1991. Iijima's discovery of multi-walled carbon nanotubes in the insoluble material of arc-burned graphite rods in 1991 and Mintmire, Dunlap, and White's independent prediction that if single-walled carbon nanotubes could be made, then they would exhibit remarkable conducting properties helped create the initial buzz that is now associated with carbon nanotubes. Nanotube research accelerated greatly following the independent discoveries by Bethune at IBM and Iijima at NEC of "single-walled" carbon nanotubes and methods to specifically produce them by adding transition-metal catalysts to the carbon in an arc discharge.
Kathleen Montagu (estimated birth between 1847 and 1907 – 28 March 1966) was the first researcher to identify dopamine in human brains. 
Working in Hans Weil-Malherbe’s laboratory at the Runwell Hospital outside London the presence of dopamine was identified by paper chromatography in the brain of several species, including a human brain. Her research was published in August 1957, followed and confirmed by Hans Weil-Malherbe in November 1957.
Albert Ludwig Sigesmund Neisser (22 January 1855, Schweidnitz – 30 July 1916, Breslau) was a German physician who discovered the causative agent (pathogen) of gonorrhea, a strain of bacteria that was named in his honour ("Neisseria gonorrhoeae").
In biology, cell theory is the historic scientific theory, now universally accepted, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. Cells are the basic unit of structure in all organisms and also the basic unit of reproduction. With continual improvements made to microscopes over time, magnification technology advanced enough to discover cells in the 17th century. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, also known as cell biology. Over a century later, many debates about cells began amongst scientists. Most of these debates involved the nature of cellular regeneration, and the idea of cells as a fundamental unit of life. Cell theory was eventually formulated in 1839. This is usually credited to Matthias Schleiden and Theodor Schwann. However, many other scientists like Rudolf Virchow contributed to the theory. It was an important step in the movement away from spontaneous generation.
The discovery of the MHC and role of histocompatibility in transplantation was a combined effort of many scientists in the 20th century. A genetic basis for transplantation rejection was proposed in a 1914 Nature paper by C.C. Little and Ernest Tyyzer, which showed that tumors transplanted between genetically identical mice grew normally, but tumors transplanted between non-identical mice were rejected and failed to grow. The role of the immune system in transplant reject was proposed by Peter Medawar, whose skin graft transplants in world war two victims showed that skin transplants between individuals had much higher rejection rates then self-transplants within an individual, and that suppressing the immune system delayed skin transplant rejection. Medawar shared the 1960 Nobel Prize in part for this work.
The causative pathogen was first identified by Naosuke Hayashi in 1920. Confident that the organism was a protozoan, Hayashi concluded, stating, "I have reached the conclusion that the virus of the disease is the species of "Piroplasma" [protozoan] in question... I consider the organism in Tsutsugamushi disease as a hitherto undescribed species, and at the suggestion of Dr. Henry B. Ward designate it as "Theileria tsutsugamushi"." Discovering the similarities with the bacterium "Rickettsia prowazekii", Mataro Nagayo and colleagues gave a new classification with the name "Rickettsia orientalis" in 1930. ("R. prowazekii" is a causative bacterium of epidemic typhus first discovered by American physicians Howard Taylor Ricketts and Russell M. Wilder in 1910; and described by a Brazilian physician Henrique da Rocha Lima in 1916.)
An important discovery was made by Patrick Manson in 1877 that mosquito could transmit human filarial parasite. Inferring from such novel discovery Albert Freeman Africanus King proposed the hypothesis that mosquitoes were the source of malaria. In the early 1890s Manson himself began to formulate the complete hypothesis, which he eventually called the mosquito-malaria theory. According to Manson malaria was transmitted from human to human by a mosquito. The theory was scientifically proved by Manson's confidant Ronald Ross in the late 1890s. Ross discovered that malaria was transmitted by the biting of specific species of mosquito. For this Ross won the Nobel Prize for Physiology or Medicine in 1902. Further experimental proof was provided by Manson who induced malaria in healthy human subjects from malaria-carrying mosquitoes. Thus the theory became the foundation of malariology and the strategy of control of malaria.
The fact that mitochondrial DNA is maternally inherited enables genealogical researchers to trace maternal lineage far back in time. (Y-chromosomal DNA, paternally inherited, is used in an analogous way to determine the patrilineal history.) This is usually accomplished on human mitochondrial DNA by sequencing the hypervariable control regions (HVR1 or HVR2), and sometimes the complete molecule of the mitochondrial DNA, as a genealogical DNA test. HVR1, for example, consists of about 440 base pairs. These 440 base pairs are compared to the same regions of other individuals (either specific people or subjects in a database) to determine maternal lineage. Most often, the comparison is made with the revised Cambridge Reference Sequence. Vilà "et al." have published studies tracing the matrilineal descent of domestic dogs from wolves.
The concept of the Mitochondrial Eve is based on the same type of analysis, attempting to discover the origin of humanity by tracking the lineage back in time.
Wallace is a pioneer in the study of mitochondrial DNA. Wallace and his colleagues introduced human mitochondrial genetics into the field of molecular genetics. In 1975, for the first time ever, Wallace could associate a genetic disorder with the mitochondrial DNA region (resistance to chloramphenicol) and in 1990 he described a mitochondrial DNA mutation as the cause of a particular form of myoclonic epilepsy. He has been instrumental in the study of the mitochondrial genome and has developed new methods for the analysis of mitochondrial DNA.
Spindle transfer, where the nuclear DNA is transferred to another healthy egg cell leaving the defective mitochondrial DNA behind, is a potential treatment procedure that has been successfully carried out on monkeys. Using a similar pronuclear transfer technique, researchers at Newcastle University led by Douglass Turnbull successfully transplanted healthy DNA in human eggs from women with mitochondrial disease into the eggs of women donors who were unaffected. In such cases, ethical questions have been raised regarding biological motherhood, since the child receives genes and gene regulatory molecules from two different women. Using genetic engineering in attempts to produce babies free of mitochondrial disease is controversial in some circles and raises important ethical issues. A male baby was born in Mexico in 2016 from a mother with Leigh syndrome using spindle transfer.
Schatz identified a region of the yeast’s nuclear DNA that was associated with the mitochondria in 1964. Later, it was discovered that mutants without the ρ-factor had no mitochondrial DNA (called ρ isolates), or that they possessed a difference in density or amount of the mitochondrial (called ρ isolates). The use of electron microscopy to view the DNA in the mitochondrial matrix helped to verify the actuality of the mitochondrial genome.