#Tmesipteris Oblanceolata

[mindblowingscience]

A small, seemingly unremarkable fern that only grows on a remote Pacific island was on Friday crowned the Guinness World Record holder for having the largest genome of any organism on Earth. The New Caledonian fern, Tmesipteris oblanceolata, has more than 50 times more DNA packed into the nucleus of its cells than humans do. If the DNA from one of the fern's cells -- which are just a fraction of a millimeter wide -- were unraveled, it would stretch out to 106 meters (350 feet), scientists said in a new study. Stood upright, the DNA would be taller than the tower that holds London's famous Big Ben bell. The fern's genome weighed in at a whopping 160 gigabase pairs (Gbp), the measurement for DNA length. That is seven percent larger than the previous record holder, the Japanese flowering plant Paris japonica.

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[meret118]

Tmesipteris oblanceolata, a fern, has a genome five times larger than the human one. It is the largest yet observed in nature, reports Nature, and its 160 billion base pairs "raises questions as to how the plant manages its genetic material."

. . .

ETA: The marbled lungfish, Protopterus aethiopicus, has the largest animal genome—thirty billion base pairs less than this fern.

[theskarb]

This tiny fern has the largest genome of any organism on Earth

[warningsine]

The tree of life offers many things, but a fern — which may seem like a not-too-complex organism — has turned out to be the living being with the largest genome. It grows in New Caledonia, an island in Oceania that’s part of overseas France. And, if the 160,750,000,000 base pairs of its DNA could be placed on top of each other, they would reach a length of about 300 feet… 50 times longer than human DNA. The recent discovery raises new questions about how much genetic material can be stored in cells and about the lack of correlation between complexity and genetics.

Tmesipteris oblanceolata grows on the fallen trunks of the forests of New Caledonia. It’s a fern that belongs to a genus of vascular plants, of which there are barely 15 known species. At least two of their first cousins were known to have giant genomes. But until now, the organism that contained DNA with what was thought to be the greatest number of base pairs was another plant, known as Paris japonica. Now, however, several researchers — who determined the genetic length of Paris japonica — have discovered that the genome of Tmesipteris oblanceolata is 7% larger.

In a new study published in the scientific journal iScience, researchers from the Royal Botanic Gardens of Kew (United Kingdom) and the Botanical Institute of Barcelona present the results of their analysis of this fern. They demonstrate that it has the largest amount of DNA stored in the nucleus of its cells compared to any living eukaryotic organism on the planet. If it were a tangle to unravel, Tmesipteris oblanceolata would extend between 344 and 347 feet.

“It’s not an iconic plant; it doesn’t have flowers, nor is it striking. In fact, it’s a weed that, if you’re not looking for it, you would trample without realizing it,” admits Jaume Pellicer, a researcher at the Botanical Institute of Barcelona. “It doesn’t even look like a fern, [or at least] it doesn’t look like the traditional image we have of them. But it has something that makes it special: it has a giant genome.”

In 2023, Pellicer and his colleague Oriane Hidalgo traveled to New Caledonia to collect samples of Tmesipteris, which they subsequently analyzed to estimate the size of its genome. This process required isolating the nuclei of thousands of cells, staining them with a fluorescent dye and then measuring how much dye had bound to the DNA within each nucleus. The more dye, the larger the genome.

“To calculate the size, we use internal standards [and] cultivated plants such as peas, rice or tomatoes, which are very well known,” Pellicer explains. In this case, the standard they used was garlic, which is the cultivated plant with the highest number of base pairs: 34 gigabases (one Gbp is equivalent to one billion base pairs). By comparison, the human genome contains about 3.2 Gbp spread across 23 chromosomes. And, when stretched, the length of DNA in each cell of garlic barely exceeds six feet.

“Tmesipteris is unique and fascinating… its ancestors evolved about 350 million years ago, long before dinosaurs walked the Earth. [The fern] is distinguished by its primarily epiphytic habit (growing primarily on tree trunks and branches),” Pellicer notes. In a video interview with EL PAÍS, he recalls that, when they encrypted the Paris japonica genome several years ago, they believed that they had reached the limit… that there could be no other organisms that were larger in genetic terms.

“The hypothesis that perhaps there was no greater diversity was based on the fact that there would be no possibility of biologically maintaining a genome beyond 150 gigabases. We were wrong,” he admits.

Such a large genome has its costs. It requires more energy resources when replicating DNA, or dividing cells. In larger cells, the integrity of the physical structure requires greater energy input. It’s more costly at a metabolic level. “That’s why we think it makes them less advantageous when it comes to adapting to constant changes, both [related to] climate and pollution,” Pellicer explains. The ferns have reproductive cycles that are much slower, because the cell cycle is much longer than in a plant with a small genome, while the demand for nutrients required to build nucleic acids is much greater. “We believe that, throughout evolution, they’ve slowly been [worn down],” Pellicer adds. In fact, he concludes, “giant genomes are the exception; despite the extraordinary diversity of genomic sizes that exist, the vast majority of plants have small or very small genomes, which is why we’re so interested in [large ones].”

Biologists call this the C-value paradox: the size of the genome doesn’t correlate with the complexity of the organism. This fact has puzzled them for decades. “It was thought that the more complex an organism was, the larger the size of its genome must be. Now we know that this isn’t the case,” Pellicer says. “And this is mainly due to the fact that most of the genome is composed of repetitive DNA sequences, which has been called ‘junk DNA,’ because it was believed that it had no function.”

When looked at with human eyes, none of the 10 organisms with the largest genomes could be seen as particularly complex living beings. In addition to T. oblanceolata and P. japonica, another fern from the genus of the first mistletoe — a European species — appears on the list, with 100.84 Gbp. In the top 10, there are only four animals, such as the marbled lungfish (129.90 Gbp) or the Neuse River Water Dog (117.47 Gbp), related to salamanders.

Pol Fernández, also a researcher from the Botanical Institute of Barcelona and a co-author of the study, gives some reasons for the order of the list of the largest genomes: “The majority are plants and, at the genomic level, they’re capable of being viable by doing many hybridization processes. When there are such gigantic genomes, it’s because there have been many duplications of genome amplifications of repeated elements. We know that this is much more frequent in plant species than in animals.”

To date, scientists around the world have estimated the genome sizes of more than 20,000 eukaryotic organisms, in the process revealing a wide range of genome sizes. These, in turn, have been found to have a profound impact, not only on their anatomy — as larger genomes need larger cells to house them and take longer to replicate — but also on how they function, evolve and where and how they live.

“Who would have thought that this small, unassuming plant, which most people would probably walk past without noticing, could hold a world record for genome size?” says Ilia Leitch, from the Royal Botanic Gardens in Kew. She adds: “Compared to other organisms, plants are incredibly DNA diverse. This should lead us to think about their intrinsic value in the broader picture of global biodiversity.”

“This discovery,” she concludes, “also raises many new and exciting questions about the limits of what is biologically possible. We hope to solve these mysteries one day.”

[tvbrasilnoticias]

Pequena Planta com Maior Genoma do Mundo: Descoberta Desafia Expectativas

Uma descoberta impressionante trouxe à luz a planta com o maior genoma conhecido no mundo. Trata-se da Tmesipteris oblanceolata, uma samambaia que, apesar de medir apenas alguns centímetros, possui um genoma de mais de 106 metros quando desenrolado, superando a altura da torre Elizabeth em Londres, onde está o famoso sino Big Ben. A pesquisa, publicada na revista iScience, foi conduzida por…

[entomoblog]

Le gigantesque génome d'une espèce de petite fougère tropicale écrase le génome humain en terme de taille

See on Scoop.it - Les Colocs du jardin

The gigantic genome of a type of fork fern smashes the human one in terms of size.

  Biggest genome ever found belongs to this odd little plant

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NDÉ

Pour en savoir plus

  → Inti De La Rosa Velazquez sur X : "The #plant (Tmesipteris oblanceolata) contains a whopping 160 billion base pairs #Genome! Biggest genome ever found belongs to this odd little plant https://t.co/A7GX4SOoR3" / X https://x.com/IntiOmics/status/1796819576883216795

  Traduction

Tmesipteris oblanceolata totalise 160 milliards de paires de bases d'ADN dans son génome ! Le plus gros génome jamais découvert appartient à cette étrange petite plante

  → Roger Highfield sur X : "Biggest genome ever found belongs to this odd little plant https://t.co/8am3os8avc A small, unassuming fern-like plant has something massive lurking within: the largest genome ever discovered, outstripping the human genome by more than 50 times" / X https://x.com/RogerHighfield/status/1796582408323735727

  Traduction

Le plus grand génome jamais découvert appartient à cette étrange petite plante https://nature.com/articles/d41586-024-01567-7

Une petite plante sans prétention ressemblant à une fougère abrite quelque chose d'énorme : le plus grand génome jamais découvert, dépassant le génome humain de plus de 50 fois.

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L'étude

  A 160 Gbp fork fern genome shatters size record for eukaryotes: iScience, 31.05.2024 https://www.cell.com/iscience/fulltext/S2589-0042(24)01111-8

  [Image] Graphical Abstract

[pc7ooo]

Обнаружен суперорганизм с ДНК длиннее человеческого в 50 раз

В Книге рекордов Гиннеса появилась новая запись: вид папоротников Tmesipteris oblanceolata стал обладателем самого большого генома среди всех живых организмов, растений и папоротников.

Подробнее на https://7ooo.ru/group/2024/06/05/524-obnaruzhen-superorganizm-s-dnk-dlinnee-chelovecheskogo-v-50-raz-grss-313819235.html

[fredborges98]

O infitamente pequeno detalhe.

As menores coisas do mundo tendem a ser as mais importantes em nossas vidas.

Por: Fred Borges

Homenagem aos grãos. Quem é pão já foi grão e entenderá a mensão e a missão de nossas existências.

Uma pequena (e rara) planta é o ser vivo com o maior genoma do mundo.

O DNA desenrolado da samambaia "Tmesipteris oblanceolata" mede mais de 106 metros e é maior do que a torre onde fica o Big Ben, em Londres, uma marca e marco do tempo.

A breve Lisístrata (em grego ático: Λυσιστράτη "que dissolve o exército") é uma comédia famosa de Aristófanes. Escrita e encenada na Atenas clássica em 411 a.C., provavelmente nas Lenéias, um dos festivais anuais atenienses sagrados em homenagem ao deus Dioníso.

As breves e curtas comédias não eram apenas engraçadas, na Grécia antiga o teatro grego era uma forma de entretenimento extremamente popular, pois abordava questões políticas relevantes e fazia grandes críticas à sociedade e nos levavam a concluir que os grandes feitos políticos,desde aquele período da história, assim como os próprios políticos, derivam do excremento de sua própria e desumana ou canina espécie pequinês em só enxergar o que é grande e está sobre a superfície das cidades.

Do mundo antigo, Aquiles nunca poderia realmente chegar a qualquer lugar já que a distância que ele teria que cobrir seria reduzida à metade um número infinito de vezes - na metade do caminho, então a meio caminho de novo, e assim por diante. Ele teria que dar um número infinito de passos cada vez menores para alcançar seu objetivo.

Experimentos sucessivos, usando aceleradores mais e mais potentes, revelaram que o núcleo de um átomo era composto de prótons e nêutrons, que por sua vez eram feitos de quarks.

Até que ponto nossos destinos são alterados por pequenos acontecimentos do dia-a-dia?

Será que um tropeço ou um pequeno acidente doméstico seriam capazes de mudar radicalmente nosso futuro?

Nosso destino é traçado não por grandes tragédias, mas pelas pequenas tragédias do dia a dia em todo decorrer das nossas limitadas vidas.

"As pequenas mentiras fazem o grande mentiroso".William Shakespeare

"O amor nasce de pequenas coisas, vive delas e por elas às vezes morre".Lord Byron

"Seja fiel nas pequenas coisas porque é nelas que mora a sua força".Madre Teresa de Calcutá

São sábios exemplos que os detalhes, no âmago do infinitamente pequeno, é lá onde reside a revolução social e científica, mas infelizmente há um descaso generalizado em observar, analisar e criticar os infinitamente pequenos detalhes, pois tendemos a considerar o visível, o táctil, o tangível, o material, o geral, as generalizações, as massificações, as comoditizações, as pasteurizações, na escala,onde a quantidade deve sua valorização, enaltecida, manifestada, mas sabemos também que num simples, pequeno ato-falho da psicanálise, reside uma brecha ou ponte para nossa psiquê ,para nos desconstruir, nos desestruturar, numa engenharia reversa ontológica e tudo que somos ou nos tornamos deriva ou se origina de pequenos detalhes ou do infinitamente pequeno.

Mas como diria Henry Ford, seguimos: "Nada é difícil se for dividido em pequenas partes".

Uns oportunizam "pequenos detalhes", outros vêem nos pequenos detalhes a real oportunidade de mudança de seus destinos.

"Quem não é fiel às pequenas coisas, jamais será nas grandes".Johann Goethe

O infinitamente pequeno dominou a obra de Stanley Kubrick e teve seu apogeu não na grande obra dirigida por ele:"2001- Uma Odisseia no Espaço", mas sua outra e derradeira direção " De olhos bem fechados".

Em "A Fonte das Mulheres" com a direção de Radu Mihaileanu, baseado em Lisístrata, obra acima mencionada, há uma passagem que um entomologista, em seu personagem, reflete: se todos valorizassem as infinitamente pequenas criações , criaturas, seres ou coisas, o mundo estaria bem melhor em qualidade de vida e a simplicidade dominaria a complexidade, e as pequenas e diminutas coisas dominariam a grandes, super, hiper,mega , estratosféricas coisas e voltaríamos a nos comportar como a humildade ou unicidade de um grão de areia,com o desprendimento,desapego do dente de leão (Taraxacum officinale), de uma gota d'água que acelerou eventos ou partículas, da metáfora das bonecas russas*, capturando nossa essência, e a divisibilidade dos quarks, e todo infinitamente detalhe nos levassem a construir a primeira máquina do tempo pluridimensional e assim teríamos o devido aprofundamento naquilo que realmente importa, o infinitamente pequeno, detalhe, grão de nossa essência.

*O significado do "matrioska" ou boneca russa no contexto e significado espiritual" está relacionado à jornada espiritual do indivíduo.

Cada camada representa um estágio de evolução, autoconhecimento e expansão da consciência.

A matrioska nos lembra que somos seres em constante transformação e que a busca pela espiritualidade é um processo contínuo e de atenção ao infinitamente pequeno.

[newsnoshonline]

La piccola felce forchetta ha il genoma più grande mai trovato Una Scoperta Straordinaria nel Regno Vegetale La felce forchetta, denominata Tmesipteris oblanceolata, ha il genoma più ampio mai osservato, con 160 miliardi di paia di basi. Questo la rende un record da oltrepassare i precedenti detentori, come la pianta da fiore Parigi giapponese e addirittura supera di 50 volte il genoma umano. Un Mistero Evolutivo La biologa evoluzionista Ilia Leitch, coinvolta nella scoperta di questo genoma straordinario, sottolinea l’arcano disegno evolutivo di questa pianta. L’accesso alle sezioni vitali del suo enorme DNA rimane una questione enigmatica, paragonata alla ricerca di un singolo libro utile in una biblioteca oceanica. Scandali nel

[yo-sostenible]

Personal investigador del CSIC halla en una planta originaria de Nueva Caledonia la cantidad récord de ADN encontrada hasta ahora en el núcleo celular de cualquier organismo de la Tierra Detalle de las estructuras reproductoras de Tmesipteris oblanceolata. / Oriane Hidalgo y Pol Fernández Tmesipteris oblanceolata es una especie rara de helecho que se encuentra en el archipiélago de Nueva Caledonia, territorio francés de ultramar situado en el suroeste del Pacífico, y en algunas de las islas vecinas como Vanuatu. El género Tmesipteris, en sí mismo, es un grupo de plantas poco estudiado que consta de alrededor de 15 especies, la mayoría de las cuales se encuentran distribuidas en diversas islas del Pacífico y Oceanía. Un género único y fascinante de helechos, cuyos ancestros evolucionaron hace unos 350 millones de años, mucho antes de que los dinosaurios pisaran la tierra. En 2023, un grupo de investigadores del Consejo Superior de Investigaciones Científicas (CSIC), dependiente del Ministerio de Ciencia, Innovación y Universidades, en el Instituto Botánico de Barcelona (IBB, CSIC-CMCNB), viajaron a Nueva Caledonia para recolectar muestras de Tmesipteris, que fueron posteriormente analizadas para estimar el tamaño de sus genomas mediante la técnica de la citometría de flujo. Los análisis revelaron que la especie Tmesipteris oblanceolata tiene un tamaño de genoma de récord de 160,45 gigabases (Gb), lo que es aproximadamente un 7% más grande que el de Paris japónica (148,89 Gb), una planta endémica de Japón que mantenía este récord desde 2010. Considerando que un par de bases -la unidad básica del ADN que consta de dos nucleótidos-, mide aproximadamente 0,34 nanómetros de longitud, si pudiésemos desenredar todo el ADN de una sola célula de este helecho sería casi igual de alto que, por ejemplo, la torre de la Giralda de Sevilla. En comparación, el genoma humano, que contiene aproximadamente 3,1 Gb distribuidos en 23 cromosomas, tiene una longitud de ADN en cada célula de tan solo alrededor de 2 metros. Más de una década de investigaciones sobre tamaños genómicos Este estudio, publicado en la revista iScience y dirigido por investigadores del Instituto Botánico de Barcelona (IBB, CSIC-CMCNB) con la participación del Real Jardín Botánico (RJB) del CSIC, Kew Gardens, la Universidad Queen Mary de Londres y el Herbario de Nueva Caledonia, no es fruto de la casualidad. En palabras de Jaume Pellicer, investigador del Instituto Botánico de Barcelona: “Basándonos en estudios previos, ya anticipábamos la existencia de genomas gigantes en Tmesipteris por lo que, este descubrimiento, lejos de ser un logro casual, es el resultado de más de una década de investigaciones explorando la diversidad de tamaños genómicos entre las plantas”. Hasta la fecha, científicos y científicas de todo el mundo han estudiado el tamaño del genoma de casi 20.000 organismos eucariotas, “revelando la existencia de una extraordinaria diversidad de tamaños de genomas a lo largo del árbol de la vida”, añade Pellicer.  Además, se ha observado que este carácter tiene un impacto profundo no solo en su anatomía, ya que “los genomas más grandes necesitan células más grandes para albergarlos, sino también en cómo funcionan, evolucionan, y dónde y cómo viven”, apunta Oriane Hidalgo, investigadora del Instituto Botánico de Barcelona. “Sorprendentemente, un tamaño genómico mayor no se refleja necesariamente en un mayor número de genes. Los organismos con genomas gigantes a menudo presentan un exceso de los llamados elementos transponibles. Estos elementos repetidos fueron primeramente descritos por la doctora Barbara McClintock al analizar los cromosomas del maíz, descubrimiento por el cual recibió el Premio Nobel de Medicina”, remarca la investigadora Ramón y Cajal del CSIC en el Real Jardín Botánico de Madrid Lisa Pokorny. Teniendo en cuenta estas observaciones, la pregunta que ahora se plantean los investigadores es por qué algunas especies tienen ...

[cavenewstimes]

New Caledonian Fern Species Has Largest Genome of Any Living Organism

Tmesipteris oblanceolata — a rare species of fork fern found on the island nation of New Caledonia, an overseas French territory situated in the Southwest Pacific — has become a world record holder. At 160.45 billion base pairs (Gbp), this record-breaking genome challenges current understanding and opens new avenues to explore the evolutionary dynamics of genomic gigantism. Tmesipteris…

[tumnikkeimatome]

ニューカレドニア原産の小さなシダ植物「Tmesipteris oblanceolata」地球上の生物の中で最大のゲノムサイズ

はじめに ニューカレドニア原産の小さなシダ植物「Tmesipteris oblanceolata」が、地球上の生物の中で最大のゲノムサイズを持つことが明らかになりました。この驚くべき発見は、学術誌「iScience」に報告されており、このシダのゲノムサイズは約160.45ギガ塩基対で、ヒトのゲノムの50倍以上の大きさです。これまでの記録保持者だった日本の花植物パリス・ジャポニカの記録を更新しました。 巨大なゲノムの発見とその意義 T.…

[afnews7]

Genoma, una felce batte il record di quello più grande mai scoperto. Ma a cosa le serva rimane un mistero

http://www.afnews.info segnala:  Non fiorisce e tende in generale a passare inosservata. Eppure si è appena aggiudicata un posto nel Guinness Book of World Records: la Tmesipteris oblanceolata ha il più grande genoma mai scoperto in un essere vivente. Lo rivelano i risultati di uno studio pubblicato su iScience, firmato da un gruppo di ricercatori del Royal Botanic Gardens di Kew (Londra, Regno…

[teknolojihaber]

Bilim insanları dünyanın en büyük genomunu küçük bir eğrelti otunda buldu

Barselona Botanik Enstitüsü'nden Jaume Pellicer liderliğindeki bir ekip, eğrelti otu Tmesipteris oblanceolata'yı aramak için Grande Terre ormanına gitti. Bu göze çarpmayan bitkinin olağanüstü bir sırrı var: Dünya üzerinde bilinen en büyük genoma sahip. Yakın zamanda yapılan bir çalışmada ayrıntılı olarak açıklanan T. oblanceolata genomu, insan DNA'sından 50 kat daha büyük bir hacme sahiptir. Bilim adamları, "Daha büyük bir genoma sahip olmak bir avantaj değil" diyor. T. oblanceolata gibi büyük miktarda DNA içeren bitkiler genellikle yavaş büyür, fotosentezde daha az verimlidir ve daha fazla besine ihtiyaç duyar. Bu faktörler iklim değişikliğine adaptasyonlarını engelleyebilir ve yok olma riskini artırabilir. Araştırmacılar, bu keşfin bitki krallığının inanılmaz çeşitliliğini ve karmaşıklığını vurguladığını ve bu dirençli organizmaların evrimsel biyolojisine yeni bir bakış açısı sağladığını belirtti. Read the full article

[xtruss]

This Tiny Fern Has The Largest Genome Of Any Organism On Earth

— By Royal Botanic Gardens, Kew | May 31, 2024

The fern species Tmesipteris oblanceolata from New Caledonia was found to have more than 50 times more DNA in each cell than humans. According to new research, its genome size is 160.45 gigabase pairs. Credit: Pol Fernandez

In a new study published in the journal iScience, researchers from the Royal Botanic Gardens, Kew and the Institut Botànic de Barcelona (IBB-CSIC) in Spain present a new record-holder for the largest amount of DNA stored in the nucleus of any living organism on the planet.

Coming in at more than 100 meters of unraveled DNA, the New Caledonian fork fern species Tmesipteris oblanceolata was found to contain more than 50 times more DNA than humans and has dethroned the Japanese flowering plant species Paris japonica, which has held this record since 2010.

In addition, the plant has achieved three Guinness World Records titles for Largest plant genome, Largest Genome, and Largest fern genome for the amount of DNA in the nucleus.

T. oblanceolata is a rare species of fern found on the island nation of New Caledonia, an overseas French territory situated in the Southwest Pacific, about 750 miles east of Australia, and some of the neighboring islands such as Vanuatu. The genus Tmesipteris is an understudied group of plants consisting of about 15 species, most of which occur across a range of Pacific Islands and Oceania.

Until now, scientists have only estimated the size of the genomes for two species of Tmesipteris—T. tannensis and T. obliqua—both of which were found to contain gigantic genomes, at 73.19 and 147.29 gigabase pairs (Gbp) respectively.

In 2023, lead authors Dr. Jaume Pellicer and Dr. Oriane Hidalgo, from the IBB and formerly of RBG Kew, traveled to New Caledonia to collect samples of Tmesipteris, which were then analyzed to estimate the size of their genomes. This involved isolating the nuclei of thousands of cells, staining them with a dye and then measuring how much dye had bound to the DNA within each nucleus—the more dye, the bigger the genome.

The previous record holder for the world's largest genome was the flowering plant, Paris Japonica at 148.89 gigabase pairs. Credit: RBG Kew

The analysis revealed the species T. oblanceolata to have a record-breaking genome size of 160.45 Gbp, which is about 7% larger than that of P. japonica (148.89 Gbp).

When unraveled, the DNA from each cell of this fern would stand taller than the Elizabeth Tower in Westminster, London, which is 96m tall and home to the world-famous Big Ben bell. For comparison, the human genome contains about 3.1 Gbp distributed across 23 chromosomes and when stretched out like a ball of yarn, the length of DNA in each cell only measures about 2m.

Dr. Pellicer, a researcher in evolutionary biology, says, "Tmesipteris is a unique and fascinating small genus of ferns, whose ancestors evolved about 350 million years ago—well before dinosaurs set foot on Earth—and it is distinguished by its mainly epiphytic habit [it grows mainly on the trunks and branches of trees] and restricted distribution in Oceania and several Pacific Islands.

"For a long time, we thought that breaking the previous size record of Paris japonica was going to be an impossible mission, but once again, the limits of biology have surpassed our most optimistic predictions.

"Based on our previous research, we anticipated the existence of giant genomes in Tmesipteris. That said, discovering the largest genome of them all is not just a feat of scientific exploration, but the result of an almost fourteen-year journey into the boundless complexity and diversity of plant genomes."

To date, scientists across the globe have estimated the genome sizes of more than 20,000 eukaryotic organisms, revealing in the process a wide range of genome sizes across the tree of life. These, in turn, have been found to have a profound impact not only on their anatomy, as bigger genomes need bigger cells to house them and take longer to replicate, but also how they function, evolve, and where and how they live.

The DNA of T. oblanceolata measures over 106m in length, making it taller than Elizabeth Tower in London, home to Big Ben. Credit: Pol Fernandez

In animals, some of the largest genomes include the marbled lungfish (Protopterus aethiopicus) at 129.90 Gbp and the Neuse River waterdog (Necturus lewisi) at 117.47 Gbp. In stark contrast, six of the largest-known eukaryotic genomes are held by plants, including the European mistletoe (Viscum album) at 100.84 Gbp.

Surprisingly, having a larger genome is usually not an advantage. In the case of plants, species possessing large amounts of DNA are restricted to being slow growing perennials, are less efficient at photosynthesis (the process by which plants convert the sun's energy into sugars) and require more nutrients (especially nitrogen and phosphates) to grow and compete successfully with their smaller-genomed neighbors. In turn, such effects may influence the ability of a plant to adapt to climate change and their risk of extinction.

Dr. Ilia Leitch, Senior Research Leader—Character Evolution, at RBG Kew, says, "Who would have thought this tiny, unassuming plant that most people would likely walk past without notice, could bear a world-beating record in genome size.

"Compared to other organisms, plants are incredibly diverse when viewed at the DNA level, and that should make us pause to think about their intrinsic value in the wider picture of global biodiversity. This discovery also raises many new and exciting questions about the upper limits of what is biologically possible, and we hope to solve these mysteries one day."

Adam Millward, Managing Editor of Guinness World Records, says, "To think this innocuous-looking fern boasts 50 times more DNA than humans is a humbling reminder that there's still so much about the plant kingdom we don't know, and that record holders aren't always the showiest on the outside."

[pc7ooo]

Ученые нашли самый большой в мире геном в крошечном папоротнике

Команда под руководством Хауме Пеллисера из Ботанического института Барселоны отправилась в лес Гранд-Терре на поиски папоротника Tmesipteris oblanceolata. Это неприметное растение хранит в себе необыкновенный секрет: самый большой геном, известный на Земле. О нем недавняя статься NY Times.

Подробнее на https://7ooo.ru/group/2024/06/02/286-uchenye-nashli-samyy-bolshoy-vmire-genom-vkroshechnom-paporotnike-grss-312779405.html