Elevator (feat. Timbaland)

093020211753

Cut for Time: Goddesses of Creation (Kristen Wiig) - SNL

093020211752

09-30-2021-1719 - 4412/3-4,5

 09-30-2021-1719 - 4412/3-4,5

MY WORST NIGHTMARE | Mannequin House

093020211716

Leperchaun Caught On Camera!

093020211712

Dr. Monster : Christmas is Cancelled (feat. Jack Douglass) | Animated Ch...

093020211705

Big Bad Bosses [B3] | Angel Official Music Video

093020211702

09-30-2021-1613 - drafting covid decrans

COVID 19 Decrease new infection

recos

infected

vaccinated infected

vaccinated recovered

Immune by single gene set, gene presence, marker presence, extrachromosomal DNA (infusions/transfusions), or DNA complexing, supramolecular and condensed, etc..

Matricing error induction cascade autoregenerative autoimmune degeneration ste 

Non-Self BTR, Organ Trans, Shell Swap, stolen childs, etc.. nonh

Immune system dysfunction, Allergy, Inflammation, HIV (viral integration transform), endogenous virus genome encoded, viral acquisition compounding, fibrotics/dystrophy/lipodys, etc.. oppinf.

Autoimmune disease resp to hyperactivation. 

Endogenous virus genome encoded, activans, mil-bil, regressions. deterior.

Cancer, ossificans, dysplasia, deformans, etc.. defos.

09-30-2021-1546 - US-Canada & Afghanistan & War

 Afghan War: Do Americans support Biden pulling out?

Published21 April

https://www.bbc.com/news/world-us-canada-56823213

09-30-2021-0339 - Myanmar shadow government calls for uprising against military

Myanmar shadow government calls for uprising against military

National Unity Government calls on all citizens to ‘revolt against the rule of the military terrorists’ in every corner of the country.

https://www.aljazeera.com/news/2021/9/7/myanmar-shadow-government-launches-peoples-defensive-war

09-30-2021-0333 - News

Families demand change after dozens died in veterans’ home COVID-19 outbreak

 Sep 29, 05:55 PM

https://www.armytimes.com/news/2021/09/29/families-demand-change-after-dozens-died-in-veterans-home-covid-19-outbreak/

https://thefallen.militarytimes.com/?source=arm-nav

https://www.tmj4.com/news/local-news/remains-of-wisconsin-world-war-ii-veteran-identified-to-be-buried-in-november

We are not at war with Wikipedia or Wikileaks.

https://news.yahoo.com/kidnapping-assassination-and-a-london-shoot-out-inside-the-ci-as-secret-war-plans-against-wiki-leaks-090057786.html

"It's a war": California turns to new, high-tech helicopters to battle wildfires

Bill Whitaker reports on the largest helicopter to ever fight fires at night, now being used in California as the state faces one of its most intense fire years ever.

https://www.cbsnews.com/news/california-wildfires-helicopters-60-minutes-2021-09-26/

Ecuador riot: Anxious families await news after fighting kills 116 inmates

Published1 hour ago

https://www.bbc.com/news/world-latin-america-58733202

‘Overdue’: Biden sets Aug. 31 for US exit from Afghanistan

By ZEKE MILLER and AAMER MADHANI

July 8, 2021

https://apnews.com/article/joe-biden-afghanistan-government-and-politics-86f939c746c7bc56bb9f11f095a95366

https://infinity-imagined.tumblr.com

The New York Times

.

Afghanistan War Ends With Little Recognition in U.S.

.

Updates on Afghanistan Sign up for a daily email with the latest news on the Taliban takeover in Afghanistan. Get it sent to your inbox. “Is it...

.

1 month ago [access 09302021]

https://www.nytimes.com/2021/08/22/us/afghanistan-war-us-reaction.html

https://infinity-imagined.tumblr.com

https://californianewstimes.com/the-second-world-war-was-fuelled-by-imperial-fantasies/542969/

09-30-2021-0313 - US 'lost' the 20-year war in Afghanistan: top US general

 US 'lost' the 20-year war in Afghanistan: top US general

Issued on: 29/09/2021 - 22:40

Modified: 29/09/2021 - 22:38

https://www.france24.com/en/live-news/20210929-us-lost-the-20-year-war-in-afghanistan-top-us-general

09-30-2021-0209 - Climate change: Arctic warming linked to colder winters

Climate change: Arctic warming linked to colder winters

By Matt McGrath

Environment correspondent

https://www.bbc.com/news/science-environment-58425526

Backstreet Boys - It's Gotta Be You (Audio)

093020210131

09-9-30-2021-0041 - USDA, AVMA, FDA ; CDC, WHO, ADA

https://www.usda.gov

https://www.avma.org/

https://www.fda.gov/

---

https://www.cdc.gov

https://www.who.int

https://www.ada.org/

---

https://www.dea.gov

09-30-2021-0018 - USA/NAC/DOM Amcans & etc. 2021

https://en.wikipedia.org/wiki/Bruce_L._Gewertz

https://www.andrewssportsmedicine.com/about/patient-stories/paul-krieger

https://www.amenclinics.com/team/jared-mendelsohn-md/

https://www.usnews.com/info/blogs/press-room/articles/2021-09-14/us-news-unveils-new-medical-review-board

https://www.fmcsa.dot.gov/mrb

https://www.health.mil/Military-Health-Topics/Conditions-and-Treatments/Physical-Disability/Disability-Evaluation/Medical-Evaluation

https://journalofethics.ama-assn.org/article/role-state-medical-boards/2005-04

oei/reports/oei-01-93-00020.pdf

https://oig.hhs.gov

https://en.wikipedia.org/wiki/Surgeon_General_of_the_United_States

https://en.wikipedia.org/wiki/United_States_Public_Health_Service_Commissioned_Corps

https://en.wikipedia.org/wiki/United_States_Department_of_Health_and_Human_Services

https://en.wikipedia.org/wiki/National_Board_of_Medical_Examiners

https://en.wikipedia.org/wiki/Category:Healthcare_accreditation_organizations_in_the_United_States

https://www.ama-assn.org

https://en.wikipedia.org/wiki/federal_medical_board_united_states_of_america

https://www.ice.gov/coronavirus

https://www.justice.gov

https://www.federalregister.gov/agencies/health-and-human-services-department

https://www.epa.gov/rcra/medical-waste

https://www.who.int/health-laws/countries/usa-en.pdf?ua=1

https://www.bop.gov

https://www.loc.gov/rr/news/fedgov.html

https://www.dol.gov/agencies/whd

https://www.gao.gov

https://www.ahrq.gov

https://en.wikipedia.org/wiki/United_States_Congress

https://en.wikipedia.org/wiki/United_States_House_of_Representatives

https://en.wikipedia.org/wiki/United_States_Senate

https://en.wikipedia.org/wiki/List_of_members_of_the_United_States_Congress_by_longevity_of_service

https://www.eia.gov

https://www.nsa.gov

https://www.blm.gov

https://www.youtube.com/watch?v=q0_g6LOa_gg

https://www.cfr.org/

Four more small energy firms could go bust next week

Business editor

https://www.bbc.com/news/business-58610561

Food shortages could be permanent, warns industry body

Business reporter, BBC News

https://www.bbc.com/news/business-58519997

https://www.nrc.no/usa

https://www.rescue.org

Republicans are the clowns in the debt ceiling circus: The act isn’t funny anymore

The GOP’s united front on the debt ceiling is the most transparent kind of political cynicism

https://wisconsinexaminer.com/2021/09/29/republicans-are-the-clowns-in-the-debt-ceiling-circus-the-act-isnt-funny-anymore/

https://sanatatea-inimii-b.com/?_=%2Fwiki%2FCategory%3AWikiProject_U.S._Congress_events%23%2BkeeBa0NTfAft3ddyzhRYgaccLICct8%3D

Revealed: LAPD officers told to collect social media data on every civilian they stop

https://www.theguardian.com/us-news/2021/sep/08/revealed-los-angeles-police-officers-gathering-social-media

Child Bride is not Human Trafficking; Human Trafficking is theft/etc. of biological/etc. code/sequence/gene/intellectual property/component/color/structure/function/feature/particle/oscillation frequency/component/whole/part/child/embryo/infant/fetus/leg/arm/limb/organ/thymus/brain/matrix/etc..

https://apnews.com/article/middle-east-child-trafficking-27d93a340c4834d497eb36e22bb72f42

Families demand change after dozens died in veterans’ home COVID-19 outbreak

Sep 29, 05:55 PM

https://www.armytimes.com/news/2021/09/29/families-demand-change-after-dozens-died-in-veterans-home-covid-19-outbreak/

09-29-2021-2243 - 4397/8-9,4400

 09-29-2021-2243 - 4397/8-9,4400

https://habr.com/ru/company/golovanov_net/blog/430016/

09-29-2021-2240 - random hexamer

A random hexamer or random hexonucleotides are for various PCR applications such as rolling circle amplification to prime the DNA.

They are oligonucleotide sequences of 6 bases which are synthesised entirely randomly to give a numerous range of sequences that have the potential to anneal at many random points on a DNA sequence and act as a primer to commence first strand cDNA synthesis. ^[1][2][3]

References[edit]

1. ^ http://www.invitrogen.com/site/us/en/home/References/protocols/nucleic-acid-amplification-and-expression-profiling/pcr-protocol/pcr-and-rt-pcr.html
2. ^ https://www.thermoscientificbio.com/general-reagents-and-accessories/primers-for-cdna-synthesis
3. ^ Hansen, KD; Brenner, SE; Dudoit, S (2010). "Biases in Illumina transcriptome sequencing caused by random hexamer priming". Nucleic Acids Res. 38: e131. doi:10.1093/nar/gkq224. PMC 2896536. PMID 20395217.

Categories: 

• Polymerase chain reaction

https://en.wikipedia.org/wiki/Random_hexamer

--------------------------------------------------------------------------------------------------------

Sunday, September 12, 2021

09-11-2021-2203 - Rhodocene bis(cyclopentadienyl)rhodium(II) dicyclopentadienylrhodium rhodium dilio dilitho lithium 45 1803

Monday, September 6, 2021

09-06-2021-0134 - Pyrazole

Saturday, September 18, 2021

09-18-2021-0759 - Cyaphide SiR3-functionalised phosphaalkynes cyaphide complex Organometallic complexes of cyaphide were first reported in 1992 From 2-phosphaethynolate anion (−OC≡P) RuH(dppe) 2(CP) phosphaalkyne (P≡CH) Methylidynephosphane Phosphorus

09-07-2021-1403 - Pseudohalogens analoge analogue psuedo

Tuesday, September 7, 2021

09-07-2021-1358 - Cyaphide

phosphorous/phosphorus, iodine, arsenic, acid

sulfur, silver, aluminum, lead

(mercury, argon)

boron, fluorine, beryllium

cesium, strontium

cobalt, uranium, graphite

cyanogen, cyanide
radon, og
antimony,
rhodium, ruthenium, lanathides, etc..

prussian blue Iron(II,III) hexacyanoferrate(II,III)

zero dipole, preon, neutronium, graviton, gauge, boson, baryon matter, pressuron, quantum interface, plasma, chain, cascade, zero state, residue, oscillation, vibration, glycerol, propylene glycol, cellulose, etc.. pressure, measure, ion, nuclear fusion, exotic, magnet, etc..

--------------------------

https://en.wikipedia.org/wiki/Periodic_table
https://en.wikipedia.org/wiki/Lanthanide_contraction

https://en.wikipedia.org/wiki/Allotropes_of_phosphorus#White_phosphorus
https://en.wikipedia.org/wiki/Potash

https://en.wikipedia.org/wiki/Phosphorus

https://en.wikipedia.org/wiki/Phosphorous

https://en.wikipedia.org/wiki/Phosphonium

https://en.wikipedia.org/wiki/Phosphine

https://en.wikipedia.org/wiki/Tetrakis(hydroxymethyl)phosphonium_chloride

https://en.wikipedia.org/wiki/Onium_ion

https://en.wikipedia.org/wiki/Zwitterion

https://en.wikipedia.org/wiki/Pnictogen

https://en.wikipedia.org/wiki/Ferrocyanide

https://en.wikipedia.org/wiki/Ylide

https://en.wikipedia.org/wiki/Magnetic_dipole

https://en.wikipedia.org/wiki/Magnetic_dipole–dipole_interaction

https://en.wikipedia.org/wiki/Zero-point_energy

https://en.wikipedia.org/wiki/Quadrupole

https://en.wikipedia.org/wiki/Overtone_band

https://en.wikipedia.org/wiki/water

https://en.wikipedia.org/wiki/Amphoterism

https://en.wikipedia.org/wiki/chalcogen

https://en.wikipedia.org/wiki/Allotropes_of_oxygen

https://en.wikipedia.org/wiki/Ozone

https://en.wikipedia.org/wiki/Cyclic_ozone

https://en.wikipedia.org/wiki/Epoxide

https://en.wikipedia.org/wiki/Carbon_tetraiodide

https://en.wikipedia.org/wiki/Triphenylphosphine

https://en.wikipedia.org/wiki/Desiccant

https://en.wikipedia.org/wiki/Hygroscopy

https://en.wikipedia.org/wiki/Dehydrogenation

https://en.wikipedia.org/wiki/hydrogenation

https://en.wikipedia.org/wiki/Protonation

https://en.wikipedia.org/wiki/Proton–proton_chain

https://en.wikipedia.org/wiki/L-shell

https://en.wikipedia.org/wiki/Hyperfine_structure

https://en.wikipedia.org/wiki/Dipole_repeller

https://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_moment

https://en.wikipedia.org/wiki/Baryon_asymmetry

https://en.wikipedia.org/wiki/Missing_baryon_problem

https://en.wikipedia.org/wiki/Sterile_neutrino

https://en.wikipedia.org/wiki/Zero_field_splitting

https://en.wikipedia.org/wiki/Permeability_(electromagnetism)

https://en.wikipedia.org/wiki/Earth%27s_magnetic_field

https://en.wikipedia.org/wiki/Multipole_radiation

https://en.wikipedia.org/wiki/Hydrogen_line

https://en.wikipedia.org/wiki/Polarization_density

https://en.wikipedia.org/wiki/Chemical_bond

https://en.wikipedia.org/wiki/Cosmic_microwave_background

https://en.wikipedia.org/wiki/Muon#Anomalous_magnetic_dipole_moment

https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance#Zero_field_NMR

https://en.wikipedia.org/wiki/Ferromagnetism

https://en.wikipedia.org/wiki/L-shell#Charged_particle_motions_in_a_dipole_field

https://en.wikipedia.org/wiki/Distributive_lattice

https://en.wikipedia.org/wiki/Ionization

https://en.wikipedia.org/wiki/Ionization#Quasi-static_tunnel_ionization

https://en.wikipedia.org/wiki/Above-threshold_ionization

https://en.wikipedia.org/wiki/Degree_of_ionization

https://en.wikipedia.org/wiki/Vacuum

https://en.wikipedia.org/wiki/pressure

https://en.wikipedia.org/wiki/temperature

https://en.wikipedia.org/wiki/volume

https://en.wikipedia.org/wiki/path

https://en.wikipedia.org/wiki/Radiation#Ionizing_radiation

https://en.wikipedia.org/wiki/Thermal_ionization

https://en.wikipedia.org/wiki/Resonance_ionization

https://en.wikipedia.org/wiki/Fast_atom_bombardment

https://en.wikipedia.org/wiki/Penning_ionization

https://en.wikipedia.org/wiki/Photoionization

https://en.wikipedia.org/wiki/Atmospheric-pressure_laser_ionization

https://en.wikipedia.org/wiki/Rydberg_atom

https://en.wikipedia.org/wiki/Atomic_radius

https://en.wikipedia.org/wiki/Exotic_atom

https://en.wikipedia.org/wiki/Grand_canonical_ensemble

https://en.wikipedia.org/wiki/Sample_preparation_in_mass_spectrometry#Matrix-assisted_laser_desorption%2Fionization

https://en.wikipedia.org/wiki/Electron

https://en.wikipedia.org/wiki/proton

https://en.wikipedia.org/wiki/neutron

https://en.wikipedia.org/wiki/Atom

High Energy Particle Physics, 

https://en.wikipedia.org/wiki/Hypernucleus

https://en.wikipedia.org/wiki/Exciton

https://en.wikipedia.org/wiki/Electron_hole

https://en.wikipedia.org/wiki/Di-positronium

https://en.wikipedia.org/wiki/High_Energy_and_Particle_Physics_Prize

https://en.wikipedia.org/wiki/Positronium_hydride

https://en.wikipedia.org/wiki/Muonium_chloride

https://en.wikipedia.org/wiki/Quantum_chromodynamics

https://en.wikipedia.org/wiki/Electroweak_interaction

https://en.wikipedia.org/wiki/Asymptotic_freedom

https://en.wikipedia.org/wiki/Gauge_theory

https://en.wikipedia.org/wiki/Deep_inelastic_scattering

https://en.wikipedia.org/wiki/Rutherford_scattering

09-29-2021-2238 - Extrachromosomal DNA & Chemical Synthesis

Extrachromosomal DNA (abbreviated ecDNA) is any DNA that is found off the chromosomes, either inside or outside the nucleus of a cell. Most DNA in an individual genome is found in chromosomes contained in the nucleus. Multiple forms of extrachromosomal DNA exist and serve important biological functions,^[1] e.g. they can play a role in disease, such as ecDNA in cancer.^[2]

https://en.wikipedia.org/wiki/Extrachromosomal_DNA

Monday, September 6, 2021

09-06-2021-0852 - Extrachromosomal circular DNA (eccDNA)

---------------------------------------------------------------------------------------------------------

In chemistry, chemical synthesis (or combination) is the artificial execution of useful chemical reactions to obtain one or several products.^[1]This occurs by physical and chemical manipulations usually involving one or more reactions. In modern laboratory uses, the process is reproducible and reliable.

A chemical synthesis involves one or more compounds (known as reagents or reactants) that will undergo a transformation when subjected to certain conditions. Various reaction types can be applied to formulate a desired product. This requires mixing the compounds in a reaction vessel, such as a chemical reactor or a simple round-bottom flask. Many reactions require some form of work-up or purification procedure to isolate the final product.^[1]

The amount produced in chemical synthesis is known as the reaction yield. Typically, yields are expressed as a mass in grams (in a laboratory setting) or as a percentage of the total theoretical quantity that could be produced based on the limiting reagent. A side reaction is an unwanted chemical reaction taking place which reduces the desired yield. The word synthesis was first used by the chemist Hermann Kolbe.^[2]

Strategies[edit]

Many strategies exist in chemical synthesis that go beyond converting reactant A to reaction product B in a single step. In multistep synthesis, a chemical compound is synthesized through a series of individual chemical reactions, each with its own work-up.^[3] For example, a laboratory synthesis of paracetamol can consist of three individual synthetic steps. In cascade reactions multiple chemical transformations take place within a single reactant, in multi-component reactions up to 11 different reactants form a single reaction product and in a telescopic synthesis one reactant goes through multiple transformations without isolation of intermediates.

Organic synthesis[edit]

Main articles: Organic synthesis and biochemistry

Organic synthesis is a special branch of chemical synthesis dealing with the synthesis of organic compounds. In the total synthesis of a complex product it may take multiple steps to synthesize the product of interest and an inordinate amount of time. Skill in organic synthesis is prized among chemists and the synthesis of exceptionally valuable or difficult compounds has won chemists such as Robert Burns Woodwardthe Nobel Prize for Chemistry. If a chemical synthesis starts from basic laboratory compounds, it is considered a purely synthetic process. If it starts from a product isolated from plants or animals and then proceeds to new compounds, the synthesis is described as a semisyntheticprocess.

Inorganic synthesis[edit]

Inorganic synthesis and organometallic synthesis are applied to the preparation of compounds with significant non-organic content. An illustrative example is the preparation of the anti-cancer drug cisplatin from potassium tetrachloroplatinate.^[4]

See also[edit]

• Beilstein database
• Chemical engineering
• Electrosynthesis
• Methods in Organic Synthesis
• Organic synthesis
• Peptide synthesis
• Total synthesis
• Automated synthesis

Chemical synthesis

Branches of chemistry

https://en.wikipedia.org/wiki/Chemical_synthesis

09-29-2021-2234 - expanded genetic code & Artificial gene synthesis

 An expanded genetic code is an artificially modified genetic code in which one or more specific codons have been re-allocated to encode an amino acid that is not among the 22 common naturally-encoded proteinogenic amino acids.^[1]

The key prerequisites to expand the genetic code are:

• the non-standard amino acid to encode,
• an unused codon to adopt,
• a tRNA that recognises this codon, and
• a tRNA synthetase that recognises only that tRNA and only the non-standard amino acid.

Expanding the genetic code is an area of research of synthetic biology, an applied biological discipline whose goal is to engineer living systems for useful purposes. The genetic code expansion enriches the repertoire of useful tools available to science.

In May 2019, researchers, in a milestone effort, reported the creation of a new synthetic (possibly artificial) form of viable life, a variant of the bacteria Escherichia coli, by reducing the natural number of 64 codons in the bacterial genome to 61 codons (eliminating two out of the six codons coding for serine and one out of three stop codons) - of which 59 used to encode 20 amino acids.^[2][3]

https://en.wikipedia.org/wiki/Expanded_genetic_code

Artificial gene synthesis, or gene synthesis, refers to a group of methods that are used in synthetic biology to construct and assemble genes from nucleotides de novo. Unlike DNA synthesis in living cells, artificial gene synthesis does not require template DNA, allowing virtually any DNA sequence to be synthesized in the laboratory. It comprises two main steps, the first of which is solid-phase DNA synthesis, sometimes known as DNA printing.^[1] This produces oligonucleotide fragments that are generally under 200 base pairs. The second step then involves connecting these oligonucleotide fragments using various DNA assembly methods. Because artificial gene synthesis does not require template DNA, it is theoretically possible to make a completely synthetic DNA molecule with no limits on the nucleotide sequence or size.

Synthesis of the first complete gene, a yeast tRNA, was demonstrated by Har Gobind Khorana and coworkers in 1972.^[2] Synthesis of the first peptide- and protein-coding genes was performed in the laboratories of Herbert Boyer and Alexander Markham, respectively.^[3][4] More recently, artificial gene synthesis methods have been developed that will allow the assembly of entire chromosomes and genomes. The first synthetic yeast chromosome was synthesised in 2014, and entire functional bacterialchromosomes have also been synthesised.^[5] In addition, artificial gene synthesis could in the future make use of novel nucleobase pairs (unnatural base pairs).^[6][7][8]

https://en.wikipedia.org/wiki/Artificial_gene_synthesis

09-29-2021-2234 - synonymous substitution

A synonymous substitution (often called a silent substitution though they are not always silent) is the evolutionary substitution of one basefor another in an exon of a gene coding for a protein, such that the produced amino acid sequence is not modified. This is possible because the genetic code is "degenerate", meaning that some amino acids are coded for by more than one three-base-pair codon; since some of the codons for a given amino acid differ by just one base pair from others coding for the same amino acid, a mutation that replaces the "normal" base by one of the alternatives will result in incorporation of the same amino acid into the growing polypeptide chain when the gene is translated. Synonymous substitutions and mutations affecting noncoding DNA are often considered silent mutations; however, it is not always the case that the mutation is silent.^{[1][2][3][4][5]}

A synonymous mutation can affect transcription, splicing, mRNA transport, and translation, any of which could alter the resulting phenotype, rendering the synonymous mutation non-silent.^[3] The substrate specificity of the tRNA to the rare codon can affect the timing of translation, and in turn the co-translational folding of the protein.^[1] This is reflected in the codon usage bias that is observed in many species. A nonsynonymous substitution results in a change in amino acid that may be arbitrarily further classified as conservative (a change to an amino acid with similar physiochemical properties), semi-conservative (e.g. negatively to positively charged amino acid), or radical (vastly different amino acid).

Degeneracy of the genetic code[edit]

Protein translation involves a set of twenty amino acids. Each of these amino acids is coded for by a sequence of three DNA base pairs called a codon. Because there are 64 possible codons, but only 20-22 encoded amino acids (in nature) and a stop signal (i.e. up to three codons that do not code for any amino acid and are known as stop codons, indicating that translation should stop), some amino acids are coded for by 2, 3, 4, or 6 different codons. For example, the codons TTT and TTC both code for the amino acid phenylalanine. This is often referred to as redundancy of the genetic code. There are two mechanisms for redundancy: several different transfer RNAs can deliver the same amino acid, or one tRNA can have a non-standard wobble base in position three of the anti-codon, which recognises more than one base in the codon.

In the above phenylalanine example, suppose that the base in position 3 of a TTT codon got substituted to a C, leaving the codon TTC. The amino acid at that position in the protein will remain a phenylalanine. Hence, the substitution is a synonymous one.

Evolution[edit]

When a synonymous or silent mutation occurs, the change is often assumed to be neutral, meaning that it does not affect the fitness of the individual carrying the new gene to survive and reproduce.

Synonymous changes may not be neutral because certain codons are translated more efficiently (faster and/or more accurately) than others. For example, when a handful of synonymous changes in the fruit fly alcohol dehydrogenase gene were introduced, changing several codons to sub-optimal synonyms, production of the encoded enzyme was reduced^[6] and the adult flies showed lower ethanol tolerance.^[7] Many organisms, from bacteria through animals, display biased use of certain synonymous codons. Such codon usage bias may arise for different reasons, some selective, and some neutral. In Saccharomyces cerevisiae synonymous codon usage has been shown to influence mRNAfolding stability, with mRNA encoding different protein secondary structure preferring different codons.^[8]

Another reason why synonymous changes are not always neutral is the fact that exon sequences close to exon-intron borders function as RNA splicing signals. When the splicing signal is destroyed by a synonymous mutation, the exon does not appear in the final protein. This results in a truncated protein. One study found that about a quarter of synonymous variations affecting exon 12 of the cystic fibrosis transmembrane conductance regulator gene result in that exon being skipped.^[9]

See also[edit]

• Ka/Ks ratio
• Missense mutation
• Nonsynonymous substitution
• Point mutation
• Expanded genetic code, where more than 20-22 natural encoded amino acids are used

https://en.wikipedia.org/wiki/Synonymous_substitution