From Mendel to epigenetics: History of genetics

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

There is no consensus about the definition of epigenetics, and the NIH Epigenomics Mapping Consortium defined epigenetics to include both heritable and non-heritable changes.

“In reality, there is no consensus about the definition of epigenetics. This is why the ‘Epigenomics Mapping Consortium’ of NIH (National Institutes of Health, USA) recently defined epigenetics in order to give room to both heritable and non-heritable changes”

• cites [20] [20] ‘Roadmap Epigenomics Project’ ‘Overview’, 2010 http://www.roadmapepigenomics.org/Not checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

At the third International Conference on Plant hybridization, Bateson proposed that the new science of heredity based on Mendel's laws be named 'genetics', and the proposal was enthusiastically approved.

“on the occasion of the third International Conference on Plant hybridization, Bateson proposed that the new science of heredity based on Mendel's laws be named ‘genetics’. This proposal was enthusiastically approved”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

As early as 1902, Walter Sutton and Theodor Boveri proposed that chromosomes are the bearers of Mendelian factors, and thought meiosis was the basis for Mendel's laws of segregation and reassortment.

“As early as 1902, Walter Sutton and Theodor Boveri proposed to consider the chromosomes as the bearers of the Mendelian factors. They rightly thought that the process of meiosis, that is to say the two successive cell divisions leading from a diploid cell to the four haploid cells that generate the gametes, was the basis for Mendel's laws of segregation and reassortment”

It may state two separate claims as one.

Mendel's experimental work on peas was crucial only in a methodological sense; his intention was not to offer general laws of heredity but only a law of the development of hybrids in plants.

“Mendel's experimental work on peas was crucial, but only in a methodological sense. Mendel's intention was not to offer general laws of heredity, but only a ‘law of the development of hybrids’ in plants”

It may state two separate claims as one.

Bateson's 1902 book introduced the terms allelomorph/allele, homozygote, and heterozygote, which imply that for a given Mendelian character each individual has two physical versions of the same hereditary element, an idea Mendel did not suggest.

“This book also introduced a technical vocabulary that rapidly became indispensable for all Mendelians: ‘allelomorph’ (or, more simply, ‘allele’), ‘homozygote’, and ‘heterozygote’; these terms imply that for a given character transmitted in a Mendelian way, each individual has two (and exactly two) physical versions of the same hereditary element — an idea that Mendel did not suggest”

• cites [2] [2] Bateson, W. A Defence of Mendel's Principles of Heredity, Cambridge University Press, Cambridge, UK, 1902Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

In a 1905 letter to Adam Sedgwick, William Bateson used the word 'genetics' to designate 'the science of heredity and variation'.

“In a letter to his colleague Adam Sedgwick in 1905, the English biologist William Bateson (1861–1926) used the word ‘genetics’ to designate ‘the science of heredity and variation’.”

It may state two separate claims as one.

In chromosomal genetics the gene became simultaneously a unit of function, a unit of recombination, and a unit of mutation, and these three notions coexisted until the discovery that genes are made of DNA.

“In the context of chromosomal genetics, a gene is also a unit of recombination (intra-chromosomal recombination resulting from crossing-overs). And finally, Muller's X-ray induced mutagenesis experiments introduced the notion that a gene is a unit of mutation. Remarkably, these three notions coexisted harmoniously (or almost) until the discovery that genes are made of DNA.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

In 1915 Morgan, with three colleagues, published The Mechanism of Mendelian Heredity, probably the most important book in the history of genetics.

“In 1915 this led him to publish, with three other colleagues, all of whom became major geneticists, what is probably the most important book in the entire history of genetics, The Mechanism of Mendelian Heredity [7].”

• cites [7] [7] Morgan, T.H.; Sturtevant, A.H.; Muller, H.J.; Bridges, C.B. The Mechanism of Mendelian Heredity, Henry Holt, New York, 1915 (Trad. fr. Le mécanisme de l’hérédité mendélienne. Lamertin, Bruxelles) sourceNot checked — no full text of the source

It may state two separate claims as one.

Some epigenetic modifications are transmissible from one generation to another while others are not; some methylation patterns seem transmissible and function as alleles, whereas histone modifications are not transmissible.

“The common feature of these changes is their stability, but this stability is more or less pronounced: some epigenetic modifications are transmissible from one generation to another while others are not. Some patterns of methylation seem to be transmissible, and therefore function as alleles, from a genetic point of view. Histone modifications are not transmissible.”

It may state two separate claims as one.

The term 'pangene' is the origin of Wilhelm Johannsen's 'gene', proposed in 1909 in the book where he also introduced 'genotype' and 'phenotype'.

“The term ‘pangene’ is the origin of Wilhelm Johannsen's ‘gene’, proposed in 1909 in the important book where he also introduced the words ‘genotype’ and ‘phenotype’ [6].”

• cites [6] [6] Johannsen, W. Elemente der Exakten Erblickeitslehre, Gustav Fischer, Jena, 1909Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Benzer proposed the cistron concept, a unit of genetic function identified by the cis-trans test, as a replacement for the classical concept of the gene.

“Benzer proposed to adopt it as the basis for the definition of the new concept of the gene that he proposed, in replacement of the obsolescent ‘classical concept’, the ‘cistron’ concept. A cistron is a unit of genetic function, identified by applying a cis-trans test.”

• cites [14] [14] Greenspan, R.J. Seymour Benzer (1921-2007), Curr. Biol., Volume 18 (2008), p. R106-R110 sourceNot checked — no full text of the source

It may state two separate claims as one.

In the 1920s the chromosomal theory became an essential part of genetics; genes had spatial significance on chromosomes, and genetic distance could be calculated from the proportion of crossing-overs.

“In the 1920s, the chromosomal theory had become an essential part of genetics and it gave a more material flavor to genetics. In the new theoretical framework, the genes had spatial significance: they were located on chromosomes, and they occupied a precise location each relative to the others: their ‘genetic distance’ could be calculated on the basis of the proportion of crossing overs.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Around 1960 the original molecular definition of the gene was that a gene is a DNA sequence that codes for the amino-acid sequence of a protein or polypeptide.

“The original idea, proposed triumphantly around 1960, was that a gene is no more nor less than a DNA sequence that codes for the amino-acid sequence of a protein (or, more generally, a polypeptide).”

It may state two separate claims as one.

Beadle and Tatum showed that a single gene controls each step in a metabolic pathway, leading to the one gene-one enzyme hypothesis.

“In the following years, still working on the mold Neurospora crassa, they showed that a single gene controls each step in a metabolic pathway. This led to the famous ‘one gene–one enzyme hypothesis’ [10].”

• cites [10] [10] Horowitz, N.K. The one gene-one enzyme hypothesis, Genetics, Volume 33 (1948), pp. 612-613 sourceNot checked — no full text of the source

It may state two separate claims as one.

In the new molecular context, the typical mutation unit is the nucleotide, the recombination unit consists of two adjacent nucleotides, and the functional unit is the sequence of nucleotides able to perform a physiological function.

“In the new molecular context, the typical mutation unit is the nucleotide; the recombination unit consists of two adjacent nucleotides; and the functional unit is the sequence of nucleotides able to perform a physiological function”

It may state two separate claims as one.

Many molecular processes known today challenge the traditional one gene-one protein dogma, and it seems hopeless to provide a general definition of the gene on exclusively molecular criteria.

“Today, many molecular processes are known that challenge the traditional ‘one gene-one protein’ dogma. In reality, it seems hopeless to provide a general definition of the gene on the basis of exclusively molecular criteria”

It may state two separate claims as one.

Mendel's memoir remained largely unknown until 1900, when his laws were rediscovered.

“Mendel's memoir remained largely unknown until 1900, when his ‘laws’ (plural instead of singular) were rediscovered.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

After Herman Muller's 1920s X-ray work on Drosophila, genetic mutation was defined as a local alteration of a chromosome in which one allele is transformed into another, the mutant gene.

“After the pioneering work of Herman Muller in the 1920s on the effect of X-rays on Drosophila, a genetic mutation was defined as a local alteration of a chromosome: a particular allele was transformed into another one, the ‘mutant gene’.”

It may state two separate claims as one.

These findings suggest that the information in the genome goes far beyond the usual picture of 20,000-25,000 protein-coding genes, and that there are many more functional units than protein-coding genes.

“These findings suggest that the information contained in our genome goes far beyond the usual picture of 20,000–25,000 protein-coding genes. There are many more functional units than those protein-coding genes.”

It may state two separate claims as one.

Benzer showed that recombination can occur in many places within a single gene and that mutation events can affect a given gene at many sites, leading to the notion of punctual mutation.

“Benzer showed that recombination (crossing over) can occur in many places within a single gene, and this allowed him to discover the fine molecular structure of the gene. Simultaneously, Benzer showed that mutation events could also affect a given gene at many sites. This was the origin of the notion of ‘punctual mutation’”

• cites [14] [14] Greenspan, R.J. Seymour Benzer (1921-2007), Curr. Biol., Volume 18 (2008), p. R106-R110 sourceNot checked — no full text of the source

It may state two separate claims as one.

Hugo de Vries, in his 1889 book Intracellular Pangenesis, supported the existence of hereditary particles in all cells of an organism and coined the word 'pangene' for them.

“One is Hugo de Vries’ use of the words ‘pangenesis’ and ‘pangene’ in a book published in 1889 as Intracellular Pangenesis [4,5]. In this book, De Vries supported the existence of hereditary particles in all the cells of an organism. For these particles, he coined the word ‘pangene’”

• cites [4] [4] De Vries, H. Intracellulare pangenesis, Gustav Fischer, Jena Gustav Fischer, 1910 (English translation: Intracellular Pangenesis. Open Court, Chicago, Trad. partielle en français dans [5])Not checked yet
• cites [5] [5] Lenay, C. La découverte des lois de l’hérédité: une anthologie (1862-1900), Presses Pocket, Paris, 1990Not checked yet

It may state two separate claims as one.

Bateson's 1902 book showed that Mendel's first law applied not only to plants but also to animals, and defended that the Mendelian laws of hybridization applied to a huge number of individual hereditary differences among virtually all sexually reproducing organisms.

“Bateson's 1902 book was certainly a key event, because it showed that Mendel's first law (the law of segregation, applying to just one character) applied not only to plants but also to animals; Bateson also defended that the Mendelian laws of hybridization did not apply only to the results of crosses between individuals of distinct varieties or species, but to a huge number of individual”

• cites [2] [2] Bateson, W. A Defence of Mendel's Principles of Heredity, Cambridge University Press, Cambridge, UK, 1902Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

In the mid-1930s genetics was conventionally subdivided into formal genetics, population genetics, and physiological genetics; population genetics provided the main theoretical basis for the Modern Synthesis.

“In the mid-1930s, genetics was conventionally subdivided into three major sub-disciplines: formal genetics proper; population genetics, which provided the main theoretical basis for the Modern Synthesis; and physiological genetics, the aim of which is to study how the genes produce their effects”

It may state two separate claims as one.

Recent data show that 98.5% of the human genome is not translated into proteins but more than 70% is transcribed into RNA, and that 70,000 promoter regions and 400,000 enhancers have been discovered in the human genome.

“Recent data show that 98.5% of our genome is not translated into proteins, but more than 70% is transcribed into RNA. Furthermore, 70,000 promoter regions (the sites where proteins bind to control gene expression) and 400,000 enhancers (regulatory sites that affect the expression of distant genes) have been discovered in the human genome [17].”

• cites [17] [17] Maher, B. The human encyclopaedia, Nature, Volume 489 (2012), pp. 46-48 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

The word 'genetics' was only coined in 1906, to designate the new science of heredity.

“However, the word ‘genetics’ was only coined in 1906, to designate the new science of heredity.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Thomas Hunt Morgan did not accept Mendelian genetics in the early 1900s, but in 1908 began working on heredity with Drosophila melanogaster using both the chromosomal theory and Mendelian genetics.

“Conversely, Thomas Hunt Morgan (1866–1945), who was the main architect of the fusion between Mendelian genetics and the chromosomal theory, did not accept the former in the early 1900s. In 1908, however, he began working on heredity with Drosophila melanogaster (fruit fly), using both the chromosomal theory of heredity and Mendelian genetics.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

William Bateson never accepted the chromosomal theory of heredity.

“For instance, William Bateson, in a sense the founding father of genetics, never accepted this theory.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Split genes, commonly found in eukaryotes and viruses, are composed of a succession of exons and introns.

“Split genes, commonly found in eukaryotes and viruses, are genes composed of a succession of exons (some of which corresponding in part or in totality to coding sequences) and introns (or intervening sequences eliminated after splicing of the exons at the RNA level).”