Genetics
Geneticsis a discipline ofbiology.[1]It is thescienceofheredity.This includes the study ofgenes,and theinheritanceofvariationandtraitsof livingorganisms.[2][3][4]In thelaboratory,genetics works by mating carefully selected organisms, and analysing their offspring. More informally, genetics is the study of how parents pass some of their characteristics to their children. It is an important part ofbiology,and gives the basic rules on whichevolutionacts.
The fact that living things inherittraitsfrom their parents has been known sinceprehistorictimes. It is used to improvecropplants and animals byselective breeding.The modern science of genetics tries to understand the process of inheritance. This began with the work ofGregor Mendelin the mid-nineteenth century.[5][6]Although he did not know the physical basis for heredity, Mendel saw that organisms inherit traits viadiscreteunits of inheritance, now calledgenes.
Modern genetics has expanded beyond inheritance. It studies the way genes work.
DNA
[change|change source]![](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e4/DNA_Overview2.png/100px-DNA_Overview2.png)
Living things are made of millions of tiny self-contained components calledcells.Inside each cell are long and complexmoleculescalleddeoxyribonucleic acid,known for short as DNA.[7]SomeDNAstoresinformationfor makingproteins.The bits of DNA which do this are known asgenes.People look different from each other mainly because they have different versions of the human set of genes.
However, a large part of DNA (more than 98% for humans) isnon-coding DNA.These sections do not serve as patterns for protein sequences.[8]What it does is code for important non-protein information. Examples are various importantRNAmolecules, and "scaffolding" bits and pieces likecentromeresandtelomeres.[9][10]
Every cell in the same living thing has the same DNA, but only some of it is used in each cell. For instance, some genes that tell how to make parts of theliverare switched off in thebrain.What genes are used can also change over time. For instance, a lot of genes are used by a child early in pregnancy that are not used later.
A person has two copies of each gene, one from their mother, and one from their father.[11]There can be several types of a single gene, which give different instructions: one version might cause a person to have blue eyes, another might cause them to have brown. These different versions are known asallelesof the gene.
Since a living thing has two copies of each gene,[12]it can have two different alleles of it at the same time. Often, one allele will bedominant,meaning that the living thing looks and acts as if it had only that one allele. The unexpressed allele is calledrecessive.In other cases, you end up with something in between the two possibilities. Both alleles are expressed.
Most of the characteristics that you can see in a living thing have more than one gene which influences them. And many genes have multiple effects on the body, because their function will not have the same effect in each tissue. The multiple effects of a single gene is calledpleiotropism.The whole set of genes is called thegenotype,and the total effect of genes on the body is called thephenotype.These are key terms in genetics.[2]
History of genetics
[change|change source]Pre-Mendelian ideas
[change|change source]We know that man started breeding domestic animals from early times, probably before the invention ofagriculture.We do not know when heredity was first appreciated as a scientific problem. The Greeks, and most obviouslyAristotle,studied living things, and proposed ideas aboutreproductionandheredity.[13]
Imre Festetics,who published work inGermanin the first part of the 19th century, was totally forgotten until recently.[14]He described several rules of genetic inheritance in his workDie genetische Gesätze der Natur,1819 (The genetic law of nature). His second law is the same as Mendel. In his third law, he developed the basic principles ofmutation.None of the histories of genetics published in the 20th century mentions him.
Probably the most publicized idea before Mendel was that ofCharles Darwin,whose idea ofpangenesishad two parts. The first, that persistent hereditary units were passed on from one generation to another, was quite right. The second was his idea that they were replenished by 'gemmules' from the somatic (body) tissues. This was entirely wrong, and plays no part in science today.[15]Darwin was right about one thing: whatever happens in evolution must happen by means of heredity, and so an accurate science of genetics is fundamental to the theory of evolution. This 'mating' between genetics and evolution took many years to organise. It resulted in themodern evolutionary synthesis.
Mendelian genetics
[change|change source]![](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Gregor_Mendel.png/150px-Gregor_Mendel.png)
The basic rules of genetics were discovered byImre Festetics,a landowner (1764–1847), and amonknamedGregor Mendelaround 1865. For thousands of years people had noticed how some traits in parents are passed to their children. However, Mendel's work was different because he designed his experiments very carefully.
In his experiments, Mendel studied how traits were passed on inpeaplants. He started his crosses with plants that bred true, and counted characters that were either/or in nature (eithertallorshort). He bred large numbers of plants, and expressed his results numerically. He used test crosses to reveal the presence and proportion ofrecessivecharacters.[16]
Mendel explained the results of his experiment using twoscientific laws:
- 1.Factors, later called genes, normally occur in pairs in ordinary body cells, yet separate during the formation of sex cells. These factors determine the organism's traits, and are inherited from its parents. Whengametesare produced bymeiosis,the two factors separate. A gamete only receives one or the other. This Mendel called theLaw of segregation.
- 2.Alleles of different genes separate independently of one another when gametes are formed. This he called theLaw of Independent Assortment.So Mendel thought that different traits are inherited independently of one another. We now know this is only true if the genes are not on the samechromosome,in which case they are notlinkedto each other.
Mendel's laws helped explain the results he observed in his pea plants. Later, geneticists discovered that his laws were also true for other living things, even humans. Mendel's findings from his work on the garden pea plants helped to establish the field of genetics. His contributions were not limited to the basic rules that he discovered. Mendel's care towards controlling experiment conditions along with his attention to his numerical results set a standard for future experiments. Over the years, scientists have changed and improved Mendel's ideas. However, the science of genetics would not be possible today without the early work of Gregor Mendel.[17][18]
Between Mendel and modern genetics
[change|change source]Between Mendel's work and 1900 the foundations ofcytology,the study of cells, was developed. The facts discovered about the nucleus andcell divisionwere essential for Mendel's work to be properly understood.[19]
- 1832:Barthélémy Dumortier,the first to observe cell division in a multicellular organism.[19][20]
- 1841, 1852:Robert Remak(1815–1865), aJewishPolish–Germanphysiologist,was the first person to state the foundation ofcell biology:that cells only derive from other cells. This was later popularized by the GermandoctorRudolf Virchow(1821–1902), who used the famous phraseomnis cellula e cellula,meaning, all cells from other cells.
- 1865: Gregor Mendel's paper,Experiments on plant hybridizationwas published.
- 1876:Meiosiswas discovered and described for the first time insea urchineggs,by German biologistOscar Hertwig(1849–1922).
- 1878–1888:Walther FlemmingandEduard Strasburgerdescribe chromosome behaviour duringmitosis.[21][22]
- 1883: Meiosis was described at the level of chromosomes, byBelgianzoologistEdouard van Beneden(1846–1910), inAscaris(roundworm) eggs.
- 1883: German zoologistWilhelm Roux(1850–1924) realised the significance of the linear structure of chromosomes. Their splitting into two equal longitudinal halves meant each daughter cell got the same chromosome complement. Therefore, chromosomes were the bearers of heredity.[23]
- 1889: Dutch botanistHugo de Vriessuggests that "inheritance of specific traits in organisms comes in particles", naming such particles(pan)genes.[24]
- 1890: The significance of meiosis for reproduction and inheritance was described in 1890 byGermanbiologistAugust Weismann(1834–1914). He noted that two cell divisions were necessary to turn onediploidcell into fourhaploidcells if the number of chromosomes was to be maintained.
- 1902–1904:Theodor Boveri(1862–1915), a German biologist, in a series of papers, drew attention to the correspondence between the behaviour of chromosomes and the results obtained by Mendel.[25]He said that chromosomes were "independent entities which keep their independence even in the resting nucleus... What comes out of the nucleus is what goes into it".
- 1903:Walter Suttonsuggested that chromosomes, which segregate in a Mendelian fashion, are hereditary units.[26]Edmund B. Wilson(1856–1939), Sutton's teacher, was the author of one of the most famous text-books in biology.[27]Wilson called this idea theSutton–Boveri hypothesis.
At this point, discoveries in cytology merged with the rediscovered ideas of Mendel to make a fusion calledcytogenetics,(cyto = cell; genetics = heredity) which has continued to the present day.
Rediscovery of Mendel's work
[change|change source]During the 1890s several biologists began doing experiments on breeding. and soon Mendel's results were duplicated, even before his papers were read.Carl CorrensandHugo de Vrieswere the main rediscoverers of Mendel's writings and laws. Both acknowledged Mendel's priority, although it is probable that de Vries did not understand his own results until after reading Mendel.[28]ThoughErich von Tschermakwas originally also credited with rediscovery, this is no longer accepted because he did not understand Mendel's laws.[29]Though de Vries later lost interest in Mendelism, other biologists built genetics into a science.[28]
Mendel's results were replicated, andgenetic linkagesoon worked out.William Batesonperhaps did the most in the early days to publicise Mendel's theory. The wordgenetics,and other terminology, originated with Bateson.[30]
Mendel's experimental results were later the object of some debate. Fisher analysed the results of the F2 (second filial) ratio and found them to be implausibly close to the exact ratio of 3 to 1.[31]It is sometimes suggested that Mendel may have censored his results, and that his seven traits each occur on a separate chromosome pair, an extremely unlikely occurrence if they were chosen at random. In fact, the genes Mendel studied occurred in only four linkage groups, and only one gene pair (out of 21 possible) is close enough to show deviation fromindependent assortment;this is not a pair that Mendel studied.[32]
Tools of genetics
[change|change source]Mutations
[change|change source]![](https://upload.wikimedia.org/wikipedia/commons/thumb/7/72/Gene-duplication.png/170px-Gene-duplication.png)
During the process ofDNA replication,errors sometimes occur. These errors, calledmutations,can have an effect on thephenotypeof an organism. In turn, that usually has an effect on the organism'sfitness,its ability to live and reproduce successfully.
Error rates are usually very low—1 error in every 10–100 million bases—due to the "proofreading" ability ofDNA polymerases.[33][34]Error rates are a thousandfold higher in many viruses. Because they rely on DNA and RNA polymerases which lack proofreading ability, they get higher mutation rates.
Processes that increase the rate of changes in DNA are calledmutagenic.Mutagenic chemicals increase errors in DNA replication, often by interfering with the structure of base-pairing, whileUVradiationinduces mutations by causing damage to the DNA structure.[33]Chemical damage to DNA occurs naturally as well, and cells useDNA repairmechanisms to repair mismatches and breaks in DNA—nevertheless, the repair sometimes fails to return the DNA to its original sequence.
In organisms which use chromosomalcrossoversto exchange DNA and recombine genes, errors in alignment duringmeiosiscan also cause mutations.[33]Errors in crossover are especially likely when similar sequences cause partner chromosomes to adopt a mistaken alignment; this makes some regions in genomes more prone to mutating in this way. These errors create large structural changes in DNA sequence—duplications,inversionsordeletionsof entire regions, or the accidental exchanging of whole parts between different chromosomes (calledtranslocation).
Punnett squares
[change|change source]Developed byReginald Punnett,Punnett squares are used by biologists to determine the probability of offspring having a particulargenotype.
Maternal | |||
---|---|---|---|
B | b | ||
Paternal | B | BB | Bb |
b | Bb | bb |
If B represents the allele for having black hair and b represents the allele for having white hair, the offspring of two Bb parents would have a 25% probability of having two white hair alleles (bb), 50% of having one of each (Bb), and 25% of having only black hair alleles (BB).
Pedigree chart
[change|change source]![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/9c/Pedigree-chart-example.svg/250px-Pedigree-chart-example.svg.png)
Geneticists (biologistswho study genetics) use pedigree charts to record traits of people in a family. Using these charts, geneticists can study how a trait is inherited from person to person.
Geneticists can also use pedigree charts to predict how traits will be passed to future children in a family. For instance, genetic counselors are professionals who work with families who might be affected by genetic diseases. As part of their job, they create pedigree charts for the family, which can be used to study how the disease might be inherited.
Twin studies
[change|change source]Since human beings are not bred experimentally, human genetics must be studied by other means. One recent way is by studying thehuman genome.Another way, older by many years, is to study twins. Identical twinsare naturalclones.They carry the same genes, they may be used to investigate how muchhereditycontributes to individual people. Studies with twins have been quite interesting. If we make a list of characteristictraits,we find that they vary in how much they owe to heredity. For example:
- Eyecolour: entirely inherited
- Weight,height:partly inherited, partly environmental
- Whichlanguagea person speaks: entirely environmental.
The way the studies are done is like this. Take a group of identical twins and a group of fraternal twins. Measure them for various traits. Do astatisticalanalysis (such asanalysis of variance). This tells you to what extent the trait is inherited. Those traits which are partly inherited will be significantly more similar in identical twins. Studies like this may be carried further, by comparing identical twins brought up together with identical twins brought up in different circumstances. That gives a handle on how much circumstances can alter the outcomes of genetically identical people.
The person who first did twin studies wasFrancis Galton,Darwin's half-cousin, who was a founder ofstatistics.His method was to trace twins through their life-history, making many kinds of measurement. Unfortunately, though he knew about mono and dizygotic twins, he did not appreciate the real genetic difference.[35][36]Twin studies of the modern kind did not appear until the 1920s.
Genetics of prokaryotes and viruses
[change|change source]The genetics ofbacteria,archaeaandvirusesis a major field of research. Bacteria mostly divide by asexual cell division, but do have a kind of sex byhorizontal gene transfer.Bacterial conjugation,transductionandtransformationare their methods. In addition, the completeDNA sequenceof many bacteria, archaea and viruses is now known.
Although many bacteria were given generic and specific names, likeStaphylococcus aureus,the whole idea of aspeciesis rather meaningless for an organism which does not have sexes andcrossing-overofchromosomes.[37]Instead, these organisms havestrains,and that is how they are identified in thelaboratory.
Genes and development
[change|change source]Gene expression
[change|change source]Gene expressionis how theheritableinformation in agene,the sequence ofDNAbase pairs, is made into a functional geneproduct,such asproteinorRNA.The basic idea is that DNA istranscribedinto RNA, which is thentranslatedinto proteins. Proteins make many of the structures and all theenzymesin acellororganism.
Several steps in the gene expression process may be modulated (tuned). This includes both the transcription and translation stages, and the final folded state of a protein. Gene regulation switches genes on and off, and so controlscell differentiation,andmorphogenesis.Gene regulation may also serve as a basis for evolutionary change: control of the timing, location, and amount of gene expression can have a profound effect on the development of the organism. The expression of a gene may vary a lot in different tissues. This is calledpleiotropism,a widespread phenomenon in genetics.
Alternative splicingis a modern discovery of great importance. It is a process wherefrom a single gene a large number of variant proteins can be assembled.One particularDrosophilagene (DSCAM) can be alternatively spliced into 38,000 differentmRNAmolecules.[38]
Epigenetics & control of development
[change|change source]Epigeneticsis the study of changes ingeneactivity which arenotcaused by changes in theDNAsequence.[39]It is the study ofgene expression,the way genes bring about theirphenotypiceffects.[40][41]
These changes in gene activity may stay for the remainder of thecell's life and may also last for many generations of cells, throughcell divisions.However, there is no change in the underlying DNA sequence of the organism.[42]Instead, non-hereditary factors cause the organism's genes to behave (express themselves) differently.[43]
Hox genesare a complex ofgeneswhoseproteinsbind to the regulatory regions of target genes. The target genes then activate or represscellprocesses to direct the final development of the organism.[44][45][46]
Extranuclear inheritance
[change|change source]There are some kinds of heredity which happen outside the cell nucleus. Normal inheritance is from both parents via the chromosomes in the nucleus of a fertilised egg cell. There are some kinds of inheritance other than this.[47]
Organelle heredity
[change|change source]Mitochondriaandchloroplastscarry some DNA of their own. Their make-up is decided by genes in the chromosomes and genes in theorganelle.Carl Corrensdiscovered an example in 1908. The four o'clock plant,Mirabilis jalapa,has leaves which may be white, green or variegated. Correns discovered the pollen had no influence on this inheritance. The colour is decided by genes in the chloroplasts.
Infectious heredity
[change|change source]This is caused by asymbioticorparasiticrelationship with amicroorganism.
Maternal effect
[change|change source]In this case nuclear genes in the femalegametearetranscribed.The products accumulate in the eggcytoplasm,and have an effect on the early development of the fertilised egg. The coiling of asnail,Limnaea peregra,is determined like this. Right-handed shells aregenotypesDdordd,while left-handed shells aredd.
The most important example of maternal effect is inDrosophila melanogaster.The protein product maternal-effect genes activate other genes, which in turn activate still more genes. This work won theNobel Prize in Physiology or Medicinefor 1995.[46]
Aspects of modern genetics
[change|change source]Much modern research uses a mixture of genetics,cell biologyandmolecular biology.Topics which have been the subject ofNobel Prizesin eitherchemistryorphysiologyinclude:
- Alternative splicing,where one gene codes for a variety of related protein products.
- Genomics,the sequence and analysis the function and structure of genomes.
- Genetic engineering,the changing of an organism's genome using biotechnology.
- Mobile genetic elements,types of DNA which can change position in the genome.
- Horizontal gene transfer,where an organism gets genetic material from another organism without being the offspring of that organism.
- Epigenetics,the study of changes in gene activity which arenotcaused by changes in the DNA sequence.
- CRISPR:In 2012,Jennifer DoudnaandEmmanuelle Charpentiersuggested that CRISPR-Cas9(enzymes from bacteria which control microbial immunity) could be used to editgenomes.This has been called one of the most significant discoveries in the history of biology.[48][49]The two scientists shared the 2020Nobel Prize in Chemistry.
Genetics of human behaviour
[change|change source]Many well-known disorders of human behaviour have a genetic component. This means that their inheritance partly causes the behaviour, or makes it more likely the problem would occur. Examples include:[50]
- Autism
- ADHD(attention deficit disorder)
- Druguse and abuse
- Risktaking
- Schizophrenia
Also, normal behaviour is also heavily influenced byheredity:
- Learningand cognitive ability
- Personality.[51]
Related pages
[change|change source]- ENCODE:the complete analysis of the humangenome
- Gene therapy
- Epigenetics
References
[change|change source]- ↑The word comes from theAncient Greekfororigin
- ↑2.02.1King R.C. Stansfield W.D. & Mulligan. P.K. 2006.A dictionary of genetics,7th ed. Oxford.
- ↑Griffiths A.J.H. et al (eds) 2000.An introduction to genetic analysis.7th ed, Freeman, New York.ISBN0-7167-3520-2[1]
- ↑Hartl D. & Jones E. 2005.Genetics: analysis of genes and genomes.6th ed, Jones & Bartlett.ISBN0-7637-1511-5.
- ↑Weiling F.Weiling, F (1991). "Historical study: Johann Gregor Mendel 1822-1884".American Journal of Medical Genetics.40(1): 1–25, discussion 26.doi:10.1002/ajmg.1320400103.PMID1887835.
- ↑The earlier ideas ofImre Festeticswere completely forgotten for many years.
- ↑There are a few exceptions to this – red blood cells, for instance, lose their DNA and most of their other structures before going into the blood.
- ↑The ENCODE Project Consortium (2012)."An integrated encyclopedia of DNA elements in the human genome".Nature.489(7414): 57–74.Bibcode:2012Natur.489...57T.doi:10.1038/nature11247.PMC3439153.PMID22955616..
- ↑Mattick J.S. 2013. The extent of functionality in the human genome.The HUGO Journal7,1.[2]
- ↑Morris K, ed. (2012).Non-coding RNAs and epigenetic regulation of gene expression: drivers of natural selection.Norfolk, UK: Caister Academic Press.ISBN978-1904455943.
- ↑Some types of living things only have one parent. Also, some living things have only one copy of each gene (bacteria, for example) and some plants have an extra set. Some genes come from only one parent, like genes on the humanY chromosomewhich is passed only from father to son.
- ↑This applies only toeukaryotesand not, for example, to bacteria.
- ↑Stubbe, Hans 1972.History of genetics: from prehistoric times to the rediscovery of Mendel's laws,transl. by T.R.W. Waters. MIT Press, Cambridge, MA. Chapter 2.
- ↑Poczai P; Bell N. & Hyvönen J 2014. Imre Festetics and the Sheep Breeders' Society of Moravia: Mendel's forgotten "research network".PLOS Biology.12(1):[3]
- ↑Olby, Robert 1985.Origins of Mendelism.2nd ed, Chicago: University of Chicago Press. p84–85ISBN0-226-62591-5.
- ↑Mendel, Gregor 1866. Versuche über Pflanzen-Hybriden.Verhandlungen des naturforschenden Vereins.Brünn. Published in English as Experiments on Plant Hybridization.Journal of the Royal Horticultural Society.26:1–30. 1901.[4]
- ↑Peters, James Arthur 1959.Classic papers in genetics.Prentice-Hall.
- ↑Linder, Patrick; Shore, David; Hall, Michael N. eds. 2004.Landmark papers in yeast biology.Woodbury N.Y.: Cold Spring Harbor Laboratory Press.ISBN 978-0-87969-643-6
- ↑19.019.1Harris, Henry 1995.The cells of the body: a history of somatic cell geneticsCold Spring Harbor Laboratory, Plainview N.Y.
- ↑Dumortier B. 1832. Researches sur la structure comparée et le développement des animaux et des végétaux.Nova Acta Phys.-Med. Acad. Caesar. Leopold.-Carolinae Nat. Curios.,part 1.16,217–311.
- ↑Flemming, Walther 1882.Beitrage zur Kenntnis der Zelle und ihrer Lebenserscheinungen.Vogel, Leipzig.
- ↑Strasburger, Eduard 1880.Zellbildung und Zelltheilung.Dabis, Jena.
- ↑Roux W. 1883.Uber die Bedeutung der Kerntheilungsfiguren.Engelmann, Leipzig.
- ↑Vries H. de 1889.Intracellular Pangenesis[5]( "pan-gene" definition on page 7 and 40 of this 1910 translation)
- ↑Boveri T. 1904.Ergebnisse uber die Konstitution der chromatischen Substanz des Zellkerns.Fischer, Jena.
- ↑Ernest W. Crow and James F. Crow (2002)."100 Years Ago: Walter Sutton and the chromosome theory of heredity".Genetics.160(1): 1–4.doi:10.1093/genetics/160.1.1.PMC1461948.PMID11805039.
- ↑Wilson E.B. 1896; 1900; 1925.The cell.Macmillan, London. The third edition ran to 1232 pages.
- ↑28.028.1Bowler, Peter J. (2003).Evolution: the history of an idea.Berkeley: University of California Press.ISBN0-520-23693-9.
- ↑Mayr E.(1982).The growth of biological thought.Cambridge: The Belknap Press of Harvard University Press. p. 730.ISBN0-674-36446-5.
- ↑Bateson W. 1906.The progress of genetic research.Report of the Third International Conference 1906 on Genetics: W. Wilks, ed. London, England: Royal Horticultural Society. pp. 90–97. From p. 91: "… I suggest for the consideration of this Congress the term Genetics, which sufficiently indicates that our labours are devoted to the elucidation of the phenomena of heredity and variation: in other words, to the physiology of Descent, with implied bearing on the theoretical problems of the evolutionist and the systematist, and application to the practical problems of breeders, whether of animals or plants".
- ↑Fisher R.A. 1936. Has Mendel's work been rediscovered?Annals of Science1:115-137.
- ↑Carlson E.A. 2004.Mendel's legacy.Cold Spring Harbor Laboratory.
- ↑33.033.133.2Griffiths A.J.F; Miller J.H. & Suzuki D.T. (eds) 2000.An introduction to genetic analysis.New York: W.H. Freeman.ISBN 0-7167-3520-2
- ↑Freisinger E. and others. 2004. Lesion (in)tolerance reveals insights into DNA replication fidelity.The EMBO journal23,1494–505.[6]
- ↑Bulmer M. 2000.Francis Galton, pioneer of heredity and biometry.Johns Hopkins, Baltimore MD. p67
- ↑Galton F. 1875. The history of twins, as a criterion of the relative powers of nature and nurture.J. Anthropological Inst.5,329–348.
- ↑This is because species descend in evolution by normal vertical inheritance.
- ↑Schmucker D; et al. (2000). "Drosophila Dscam is an axon guidance receptor exhibiting extraordinary molecular diversity".Cell.101(6): 671–684.doi:10.1016/S0092-8674(00)80878-8.PMID10892653.S2CID13829976.
- ↑By "DNA sequence" we mean the sequence ofnucleotidebase pairsin anexon,which is the part of a gene which determines the sequence ofamino acidsin the coded protein.
- ↑King R.C. Stansfield W.D. & Mulligan P.K. 2006.A dictionary of genetics,7th ed. Oxford. p146
- ↑Carey, Nessa 2011.The epigenetics revolution: how modern biology is rewriting our understanding of genetics, disease and inheritance.London: Icon Books.ISBN 978-184831347-7
- ↑Adrian Bird (2007). "Perceptions of epigenetics".Nature.447(7143): 396–398.Bibcode:2007Natur.447..396B.doi:10.1038/nature05913.PMID17522671.S2CID4357965.PMID 17522671
- ↑"Special report: 'What genes remember' by Philip Hunter | Prospect Magazine May 2008 issue 146".Archived fromthe originalon 2008-05-01.Retrieved2013-01-15.
- ↑Lewis E.B. 1995. Thebithoraxcomplex: the first fifty years.Nobel Prizelecture. Repr. in Ringertz N. (ed) 1997.Nobel lectures, Physiology or Medicine.World Scientific, Singapore.
- ↑Lawrence P. 1992.The making of a fly.Blackwell, Oxford.
- ↑46.046.1Gehring, Walter J. 1998.Master control genes in development and evolution.Yale University Press.ISBN 0-300-07409-3
- ↑Klug W.S.et al2012.Concepts of genetics.10th ed, Pearson, chapter 9.ISBN978-0-321-79578-6
- ↑Pollack, Andrew (May 11, 2015)."Jennifer Doudna, a pioneer who helped simplify genome editing".The New York Times.RetrievedMay 12,2015.
- ↑Jennifer A. Doudna and Samuel H. Sternberg. 2017.A crack in creation: gene editing and the unthinkable power to control evolution.New York: Houghton Mifflin Harcourt.
- ↑Plomin, Robertet al2001.Behavioral genetics.4th ed, New York: Worth, Overview, 1–5.ISBN0-7167-5159-3
- ↑Ghost in your genes.NOVA, PBS
Standard works
[change|change source]- Alberts B, Bray D, Hopkin K, Johnson A, Lewis J, Raff M, Roberts K, Walter P. 2013.Essential cell biology,4th Edition. Garland Science.ISBN 978-1-317-80627-1.
- Griffiths A.J.H. & others 2000.An introduction to genetic analysis.7th ed, Freeman, New York.ISBN0-7167-3520-2[7]
- Hartl D. & Jones E. 2005.Genetics: analysis of genes and genomes.6th ed, Jones & Bartlett.ISBN0-7637-1511-5.
- King R.C; Mulligan P.K. & Stansfield W.D. 2013.A dictionary of genetics.8th ed,Oxford University Press.ISBN978-0-19-976644-4
- Klug, William S.et al2012.Concepts of genetics.10th ed, Pearson.ISBN0-321-79578-4.
- Lodish H, Berk A, Zipursky LS, Matsudaira P, Baltimore D, Darnell J(2000. Molecular Cell Biology. 4th ed, New York: Scientific American Books.ISBN 978-0-7167-3136-8
Works on genetic manipulation
[change|change source]- Jennifer A. Doudna and Samuel H. Sternberg. 2017.A Crack in Creation: gene editing and the unthinkable power to control evolution.Houghton Mifflin Harcourt.ISBN 978-1-847-92382-0
- Carey, Nessa 2011.The epigenetics revolution: how modern biology is rewriting our understanding of genetics, disease and inheritance.London: Icon Books.ISBN 978-184831347-1
- Carey, Nessa 2019.Hacking the code of life: how gene editing will write our futures.London: Icon Books.ISBN 978-1-78578-625-9