Sony Pixel Power calrec Sony

February 28, 2020

29/02/2020

Mysterious mutational freedom' in mitochondrial molecule may have been a key adaptation in animal evolution Mitochondrial transfer-RNAs evolved special mutation-resilient structure in complex animals.

February 28, 2020

JUPITER, FL A set of molecules needed for efficient energy production in cells apparently underwent a radical change during early animal evolution so they could continue to function despite their relatively high mutation rate, according to a new study from scientists at Scripps Research.

In the study, published in Nature Communications, the scientists analyzed a set of 22 closely related mitochondrial molecules. Mitochondria are tiny, bacteria-like organelles that are the major producers of chemical energy in cells; they contain their own small DNA genomes, which are separate from the main genome in the cell nucleus. The 22 mitochondrial molecules, called mitochondrial transfer RNAs (mt-tRNAs), play a central role in translating the information in mitochondrial genes into mitochondrial proteins.

The researchers found evidence that as more complex animals evolved from the simplest ones, their mt-tRNAs evolved to have an unusual basic structure, which conferred a remarkable capacity to keep working properly despite frequent mutations to their genes. Mitochondrial DNA is more vulnerable to mutations, especially in complex animals.

The mutational freedom of these novel mt-tRNA structures appears to be a powerful adaptive mechanism for withstanding the enhanced mutation rate of mitochondrial DNA in higher animals, says senior author Paul Schimmel, PhD, a professor in the Department of Molecular Medicine at Scripps Research.

Mitochondria are found in numbers up to thousands per cell in virtually all plants and animals, as well as in many simpler organisms. Theyre widely believed to have originated as bacteria that could live symbiotically inside the cells of some early, simple life forms. But after hundreds of millions of years of evolution, they have become essential producers of chemical energy in all complex species. They use oxygen to produce this energy and that need for oxygen is why animals breathe.

One of the problems with mitochondria, from a human health perspective, is that they are especially vulnerable to damage. Mitochondria contain their own circular DNA genomes, which in humans encode 37 mitochondrial molecules including the 22 mt-tRNAs. Compared with ordinary DNA in the cell nucleus, mitochondrial DNA is not as well protected from DNA-damaging compounds that sometimes arise in cells. In fact, mitochondria themselves give rise to many DNA-damaging oxygen compounds as byproducts of their own energy-making process especially in more complex animals that move around and burn lots of energy doing so. Thus, animal mitochondrial DNA has a faster mutation rate than animal cell-nucleus DNA.

Damage to mitochondrial genes also can't be managed as easily as in cell-nucleus genes. In sexually reproducing organisms, mitochondria and the DNA they contain originate always from the mother's egg cell. There is no recombination with paternal DNA to remove defects, as occurs for the main part of the genome. Since mutations that occur randomly are much more likely to be harmful than helpful, genomes that are passed along in this manner could simply accumulate defects, from one generation to the next, until they become totally dysfunctional. Biologists still do not fully understand how mitochondria have avoided this fate.

In their study, Schimmel and colleagues, including co-corresponding author Bernhard Kuhle, PhD, a postdoctoral research associate in the Scripps Research Laboratories for tRNA Synthetase Research, addressed this question with an analysis of mitochondrial tRNAs. The 22 distinct mt-tRNAs account for most of the molecules encoded by the mitochondrial genome. Like non-mitochondrial tRNAs, these molecules work as essential decoders of the genetic code, linking nucleotide sequences copied out from genes to corresponding amino acids, which are the building blocks of proteins.

The scientists analyzed the evolution of modern animal mt-tRNAs by comparing the mt-tRNAs of simple and complex animals and other, more evolutionarily distant organisms, and by mutating human mt-tRNAs to see how this changed their functions.

They found evidence suggesting that when the first moderately complex animals appeared on Earth, their mt-tRNAs evolved smaller, simpler structures, which made them more likely to maintain their decoder functions even when they accumulated new mutations.

This adaptation for mutational freedom would have allowed the genes for mitochondrial tRNAs to mutate even faster, and although mt-tRNA-linked genetic diseases are not very common in humans in an absolute sense, mt-tRNA genes are considered a relative hotspot for genetic disease. From this perspective, tRNA-associated mitochondrial diseases are a necessary price we pay for the high adaptive power of these important molecules, Schimmel says.

Authors of Relaxed sequence constraints favor mutational freedom in idiosyncratic metazoan mitochondrial tRNAs are Bernhard Kuhle and Paul Schimmel of Scripps Research, and Joseph Chihade of Carleton College.

Support was provided by the National Institutes of Health (R01 GM125908, R15 GM071392), the National Foundation for Cancer Research and the Skaggs Foundation.

Chemistry Schimmel, Paul
LINK: https://www.scripps.edu/news-and-events/press-room/2020/20200228-schim...
See more stories from scripps

Most recent headlines

03/06/2024

Dalet and Veritone Reach Agreement to Distribute, Transact and Monetize Media Archives

Dalet, a leading technology and service provider for media-rich organizations, a...

28/04/2024

Mediahaus delivers the first SRT live-streaming sports production over 5G with URSA Broadcast G2

Mediahaus delivers the first SRT live-streaming sports production over 5G with U...

29/03/2024

Dalet to Demo AI-Enabled Production, Automation and Monetization at NAB Show

PARIS Dalet has announced that during the 2024 NAB Show (booth #W1713), attendees can experience firsthand Dalet's collaborative, AI-enabled workflows that ...

29/03/2024

DirecTV Inks Deal to Carry 2024 Colorado Rockies Games

DENVER AND EL SEGUNDO, Calif. DirecTV has announced a new agreement with Major League Baseball that will allow Colorado Rockies fans to see this season's ga...

29/03/2024

S&P: Media, Telecom M&A Plunges to 13-Month Low

S&P Global Market Intelligence has released new data showing that dealmaking in the North America for media and telecom companies remains in the doldrums....

29/03/2024

NAB Show: Pebble Launches PRIMA Software Platform

EPSOM, Surrey, UK The automation, content management, and integrated channel specialist Pebble, has announced that it will be launching a new software platform ...

29/03/2024

Gray Television to Air Arena Football League Local Games

ATLANTA Gray Television Inc. has inked a multi-year agreement with the Arena Football League to bring Saturday arena football games over-the-air to local audien...

29/03/2024

Muvhango: Thursday's episode, 28 March 2024 [VIDEO]

Muvhango: Thursday's episode, 28 March 2024 [VIDEO]Stay up to date with the latest episodes of your favourite South African soapie on The South African webs...

29/03/2024

Gqeberha: The Empire - Thursday's episode, 28 March 2024 [VIDEO]

Gqeberha: The Empire - Thursday's episode, 28 March 2024 [VIDEO]Stay up to date with the latest episodes of your favourite South African soapie on The South...

29/03/2024

My Brother's Keeper: Thursday's episode, 28 March 2024 [VIDEO]

My Brother's Keeper: Thursday's episode, 28 March 2024 [VIDEO]Stay up to date with the latest episodes of your favourite South African soapie on The Sou...

29/03/2024

Umkhokha: The Curse - Thursday's episode, 28 March 2024 [VIDEO]

Umkhokha: The Curse - Thursday's episode, 28 March 2024 [VIDEO]Stay up to date with the latest episodes of your favourite South African soapie on The South ...

29/03/2024

Skeem Saam: Thursday's episode, 28 March 2024 [VIDEO]

Skeem Saam: Thursday's episode, 28 March 2024 [VIDEO]Missed an episode of Skeem Saam? No problem! Watch the latest episode of your favourite South African s...

29/03/2024

House of Zwide: Thursday's episode, 28 March 2024 [VIDEO]

House of Zwide: Thursday's episode, 28 March 2024 [VIDEO]Stay up to date with the latest episode of South African soapie House of Zwide on The South African...

28/03/2024

No votes for all

Out of an estimated 20,000 journalists in Pakistan, less than one thousand are women according to a recent Gender Disparity Report published by the Internationa...

28/03/2024

Give Me the Backstory: Get to Know 8 Women Filmmakers With Shorts at the 2024 Sundance Film Festival

A still from Jasmin Baumgartner's Bye Bye, Bowser, which screened as part ...

28/03/2024

The Best Shared Storage For Video Production

alt= class=wp-image-12214 data-lazy-src=/wp-content/uploads/2024/03/Best-Shared-Storage-EVO-logo-960x540-1.jpg/> Embarking on a cinematic journey or crafting a ...

28/03/2024

Future-Proofing the B-52

L3Harris is upgrading critical electronic warfare systems to ensure the iconic aircrafts spectrum superiority for decades to come....

28/03/2024

Supporting the RCAF for more than 25 Years with L3Harris' WESCAM MX-Series

L3Harris' WESCAM MX-Series EO/IR systems have supported the RCAF for more than 25 years....

28/03/2024

ENCO to Add AI News Anchor to Qimera Virtual Production Set

NOVI, Mich. During the 2024 NAB Show, ENCO will be showcasing an AI-driven virtual anchor delivering live news from a realistic 3D virtual news set....

28/03/2024

Johan de Nysschen Named President and CEO of ARRI Americas

MUNICH ARRI has announced that Johan de Nysschen has been put in charge of the ARRI Americas team as president and CEO ARRI Americas Inc....

28/03/2024

Fubo Inks Carriage Deal with YES Network

NEW YORK The YES Network and FuboTV have reached a multi-year carriage agreement that will allow Fubo to launch YES in its Pro base channel plan in time for YES...

28/03/2024

Dalet to Demo AI-Enabled Production, Automation and Monetization at NAB 2024

PARIS Dalet has announced that during its 2024 NAB showcase (booth #W1713), attendees can experience firsthand Dalet's collaborative, AI-enabled workflows t...

28/03/2024

Blackmagic Design Used on 2024 Oscar Nominated Films

Blackmagic Design Used on 2024 Oscar Nominated Films Brie Clayton March 28, 2024 0 Comments Blackmagic Design congratulates the many film professional...

28/03/2024

Arkona to Introduce BLADE//master Control and Orchestration Service at NAB 2024

Arkona to Introduce BLADE//master Control and Orchestration Service at NAB 2024 Brie Clayton March 28, 2024 0 Comments New option for BLADE//runner ke...

28/03/2024

Join Maxon for NAB 2024

Join Maxon for NAB 2024 Brie Clayton March 28, 2024 0 Comments Maxon returns to NAB with presentations by artists from around the world and demos of t...

28/03/2024

Boston Conservatory to Present Center Stage Production of A Midsummer Night's Dream at The Huntington

Boston Conservatory to Present Center Stage Production of A Midsummer Night'...

28/03/2024

The 4K cameras giving audiences an astronaut's view of Earth

TVBEurope meets Charles Black, founder and CEO of Sen, which has sent a payload of 4K cameras to the ISS to livestream images of Earth to audiences around the w...

28/03/2024

2024 Big Night In Raises $145k to Support Triangle Arts Councils

Capitol Broadcasting and WRAL-TV once again proudly supported our local arts community with the broadcast of Big Night in for the Arts Thursday, March 7, 2024. ...

28/03/2024

JIC, MRC Announce Accord On Roles In Judging Measurement Companies

With more companies offering different approaches to measuring television viewing and campaign effectiveness, two of the groups that evaluate potential media bu...

28/03/2024

Hulu Added to Disney Plus App for Bundle Subscribers

The Walt Disney Co. said that it launched Hulu on Disney Plus, which makes Hulu programming available via the Disney Plus app....

28/03/2024

GroupM To Double Ad Spending On Women's Sports Programming

Giant media buyer GroupM said it plans to double its media spending on women's sports....

28/03/2024

Scripps Renews State Farm As Sponsor of Friday Night WNBA on Ion

Scripps Sports said that State Farm has signed a new multi-year agreement to continue as the title sponsor of Ion's Friday night WNBA telecasts....

28/03/2024

Elisabeth Moss, Kerry Washington Sign On for Imperfect Women' on Apple TV Plus

Elisabeth Moss and Kerry Washington will star in, and executive produce, Imperfe...

28/03/2024

Telemundo Station Group Addresses Climate Change With Month-Long Initiative

Telemundo Station Group launches the month-long climate change initiative Our Planet Thursday, March 28. The multiplatform campaign ends on Earth Day, April 22,...

28/03/2024

Circle City Broadcasting Renews Nielsen Ratings Deal

Nielsen said that Circle City Broadcasting, owner of WISH-TV in Indianapolis, has renewed its local TV measurement deal....

28/03/2024

Lionsgate Extends Deal With Seth Rogen's Point Grey Pictures

Lionsgate Television said it extended its deal with Point Grey Pictures, the production company led by Seth Rogen, Evan Goldberg and James Weaver....

28/03/2024

Ariana DeBose Back as Tonys Host

Ariana DeBose returns as host of the Tony Awards Sunday, June 16, on CBS and Paramount Plus. It is her third consecutive time hosting, and it will be the 77th T...

28/03/2024

The Steve Wilkos Show' Renewed for Season 18

The Steve Wilkos Show has been renewed for its 18th season in national syndication, Tracie Wilson, executive VP, NBCUniversal Syndication Studios & E! News, sai...

28/03/2024

Sinclair Selects Embrace as Its Media Orchestration Engine

PARIS Embrace, a developer of advanced automation and orchestration software solutions, has announced that Sinclair Broadcast Group has selected Embrace's P...

28/03/2024

Nielsen and Circle City Broadcasting Renew Local TV Measurement Deal

NEW YORK Nielsen has a multi-year renewal with Circle City Broadcasting, Indianas only locally owned and operated broadcast and digital news media network, for ...

28/03/2024

JVC to Demo Its First Ever 40x Zoom PTZ Camera Series at 2024 NAB Show

LAS VEGAS JVC Professional Video has announced that it will debut its new KY-PZ540 Series PTZ Cameras with 40x zoom at 2024 NAB Show (Booth C4720)....

28/03/2024

Brightcove Launches Cloud Playout 2.0

BOSTON Brightcove has announced the launch of Cloud Playout 2.0, a platform that the company said will offer customers new ways to create linear channels, monet...

28/03/2024

NBC Sports Chicago to Air First-Ever Animated Real-Time Local Sports Telecast

The Chicago Blackhawks and NBC Sports Chicago have announced a collaboration with the NHL to bring fans the first-ever local animated real-time sports telecast....

28/03/2024

The Best News Coverage is Real, Live, Balanced, Professional

The Best News Coverage is Real, Live, Balanced, Professional Andy Marken March 28, 2024 0 Comments Hero image source News of the World, Perfect Wo...

28/03/2024

DJ Sbu makes shock return to SABC radio after almost a decade

DJ Sbu makes shock return to SABC radio after almost a decadeRevered radio host, media personality, philanthropist, and businessman DJ Sbu will finally be back ...

28/03/2024

Smoke and Mirrors: Thursday's episode, 28 March 2024 [VIDEO]

Smoke and Mirrors: Thursday's episode, 28 March 2024 [VIDEO]Stay up to date with the latest episodes of your favourite South African soapie on The South Afr...

28/03/2024

VEON Pays Back Outstanding Balance and Cancels its Revolving Credit Facility

28 Mar 2024 VEON Pays Back Outstanding Balance and Cancels its Revolving Credit Facility Amsterdam, 28 March 2024, 09.30 CET - VEON Ltd. (Nasdaq: VEON, Euronex...

28/03/2024

TNT Sports Gets Its College Game On for March Madness Audio

TNT Sports Gets Its College Game On for March Madness Audio Marching bands, crowds make up for lack of court FX and wired players By Dan Daley, Audio Editor ...

28/03/2024

Cosm/ESPN Deal Will Bring NBA, NHL, Tennis, College Football, and More to Shared Reality' Venues

Cosm/ESPN Deal Will Bring NBA, NHL, Tennis, College Football, and More to Share...

28/03/2024

MLB 2024: The Famous Group, Miami Marlins Team Up for AI-Powered Intro for All 2024 Home Games

MLB 2024: The Famous Group, Miami Marlins Team Up for AI-Powered Intro for All 2...