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Un estudio identificó el "enredo" genómico que explicaría los cerebros complejos de pulpos, calamares y sepias

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Los pulpos, los calamares y las sepias poseen los cerebros más grandes y complejos entre todos los invertebrados. Son capaces de resolver problemas, cambiar de color en milésimas de segundo y exhibir comportamientos que durante décadas llamaron la atención de la biología evolutiva.

Es por este panorama que la pregunta que sobrevolaba a los investigadores era directa: ¿cómo lograron estos animales desarrollar sistemas nerviosos tan sofisticados y qué papel pudo tener la organización de su genoma en ese proceso? La respuesta, según un equipo de científicos de la Universidad de Viena, podría no estar en los genes en sí mismos, sino en la manera en que el ADN se pliega y se organiza dentro de la célula.

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Un análisis comparativo de la arquitectura tridimensional del genoma en tres especies de cefalópodos coleoideos reveló que una reorganización cromosómica masiva, ocurrida hace cientos de millones de años, alteró la forma en que regiones distantes del ADN interactúan entre sí. Ese cambio habría modificado los patrones de regulación genética y facilitado la aparición de rasgos biológicos inéditos, entre ellos sus elaborados sistemas nerviosos.

La supresión de la secuencia en el calamar provocó defectos en los lóbulos ópticos y alteró genes ubicados a millones de pares de bases de distancia. (Imagen Ilustrativa Infobae)

Los hallazgos, publicados en la revista Nature Communications, introducen un concepto que los autores denominan “enredo regulatorio”: la acumulación progresiva de interdependencias entre elementos del genoma que, al quedar próximos tras los reordenamientos cromosómicos, se entrelazan en redes regulatorias cada vez más complejas.

“El genoma no es solo una secuencia de genes. Está plegado en una estructura tridimensional compleja”, señaló la autora principal, la doctora Thea Rogers, investigadora del Departamento de Neurociencia y Biología del Desarrollo, según el comunicado de prensa de la Universidad de Viena. “Comprender cómo evoluciona esa estructura es cada vez más importante para entender cómo surgen nuevas formas de complejidad biológica”, agregó.

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La estructura estable y las conexiones flexibles del genoma

El estudio integró datos de estructura de la cromatina, actividad génica y accesibilidad del ADN en tres especies representativas de los principales linajes de cefalópodos coleoideos: el calamar Euprymna scolopes, la sepia Sepia officinalis y el pulpo Octopus bimaculoides.

El mayor nivel de enredo regulatorio en los octopodiformes impone restricciones a la expansión de su genoma que no afectan a calamares y sepias. (Imagen Ilustrativa Infobae)

Los investigadores encontraron que las grandes unidades estructurales del genoma, conocidas como dominios de cromatina, es decir, regiones delimitadas por barreras de aislamiento que organizan el material genético a gran escala, se mantuvieron en buena medida conservadas a lo largo de la evolución de estos animales.

Las conexiones más finas, llamadas bucles de cromatina, mostraron un comportamiento opuesto. Estos bucles acercan zonas distantes del ADN para regular la actividad de determinados genes, y resultaron mucho más dinámicos: variaban entre especies, entre tejidos y entre etapas del desarrollo embrionario. Según se detalla en el estudio, apenas tres bucles con genes compartidos se conservaban en las tres especies analizadas, lo que sugiere que se renuevan con rapidez evolutiva mientras la estructura de mayor escala permanece como un andamio estable.

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Los bucles hallados cerca de genes vinculados al sistema nervioso resultaron especialmente relevantes. En Octopus bimaculoides, los tejidos neurales presentaron una cantidad de bucles notablemente superior a la de los órganos internos, consistente con las elevadas demandas regulatorias que impone el cerebro de estos animales. Según el comunicado de prensa, estos hallazgos desafían la idea de que la arquitectura del genoma es una consecuencia pasiva de la evolución y proponen, en cambio, que la organización tridimensional del ADN moldea activamente la trayectoria evolutiva.

El experimento que puso a prueba una región regulatoria dentro de un bucle

Los científicos aplicaron edición genética con CRISPR-Cas9 para eliminar una región del gen Quaking B en embriones del calamar Euprymna berryi. (Imagen Ilustrativa Infobae)

Para verificar que estas estructuras no eran meras curiosidades topológicas, el equipo recurrió a la edición genética mediante CRISPR-Cas9, una herramienta que permite cortar y modificar secuencias específicas del ADN.

Los investigadores eliminaron, en embriones del calamar Euprymna berryi, un fragmento de aproximadamente mil pares de bases, las unidades que componen la cadena genética, situado dentro de un intrón del gen Quaking B. Un intrón es un segmento no codificante ubicado en el interior de un gen, y en este caso el gen está implicado en el desarrollo neural y forma parte de un bucle de cromatina conservado en las tres especies.

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Los resultados mostraron alteraciones claras en el desarrollo de los embriones editados. De los 25 ejemplares intervenidos, todos presentaron signos de retraso, y entre un tercio y dos tercios exhibieron defectos morfológicos específicos en el cerebro, como lóbulos ópticos reducidos y brazos más pequeños o ausentes.

El análisis de expresión génica reveló que la eliminación de esa secuencia no solo afectó al gen que la albergaba, sino que alteró genes ubicados a millones de pares de bases de distancia, según se detalla en el estudio. Algunos de esos genes afectados son exclusivos de los cefalópodos. El trabajo concluye que la región eliminada “integra señales regulatorias críticas para la expresión de genes neurales y el desarrollo”.

Por qué Octopus bimaculoides mostró un genoma más “enredado”

Los tejidos neurales del pulpo Octopus bimaculoides registraron una cantidad de bucles de cromatina superior a la observada en sus órganos internos. (Imagen Ilustrativa Infobae)

La investigación también reveló diferencias llamativas entre los dos grandes linajes de cefalópodos coleoideos. Octopus bimaculoides, representante de los octopodiformes, el grupo que incluye a los pulpos, exhibió un genoma más “mezclado” que el de las dos especies de decapodiformes analizadas, el calamar y la sepia.

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Según el comunicado, esa diferencia obedece a una historia de fusiones cromosómicas más extensas en el linaje de los pulpos, que habría generado estados regulatorios más entrelazados.

En términos concretos, los bucles de cromatina de esta especie resultaron notablemente más grandes: su tamaño mediano alcanzó los 2,9 millones de pares de bases, frente a 1,6 millones en el calamar y 1,3 millones en la sepia. Más de la mitad de esos bucles contenían genes cuyos equivalentes en los calamares se encontraban dispersos en cromosomas diferentes, lo que indica que las fusiones cromosómicas remodelaron profundamente la organización regulatoria del genoma de Octopus bimaculoides.

Los autores proponen que este mayor enredo regulatorio impone restricciones que limitan la expansión futura del genoma en los octopodiformes, a diferencia de la expansión genómica más pronunciada que se observó en los decapodiformes. Según se detalla en el estudio, la organización tridimensional del genoma no solo refleja la historia evolutiva, sino que condiciona las trayectorias posibles, un hallazgo que replantea la comprensión de cómo surgen los rasgos complejos en la naturaleza.

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Winery owned by Ilhan Omar’s husband shuttered due to fraud, James Comer says

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A winery co-owned by the husband of Rep. Ilhan Omar, D-Minn., was shuttered amid fraud claims, House Oversight Committee Chairman James Comer, R-Ky., said.

Comer said over the weekend that the winery had been selling empty barrels to investors under the guise of «wine to be aged.»

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«I can tell you from our initial investigation of Omar and her financial disclosure form that there are multiple fronts where you could get a search warrant issued,» Comer told Trey Gowdy on Fox News’ «Sunday Night in America.»

«First of all, not only was there a huge discrepancy in the financial disclosure form, there was the winery that was the big base of her $25 million listing on her financial disclosure form. That winery has, according to the press, been shut down because of fraud.»

ILHAN OMAR’S EMBATTLED HUSBAND APPEARS AT SCENE OF HSI RAID IN MIDST OF CRIMINAL FRAUD INVESTIGATION

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The winery, co-owned by the congresswoman’s husband, Tim Mynett, shut down in April this year amid congressional scrutiny over Omar’s finances.

His and his business partner’s lawyers told the Minnesota Reformer, «Any suggestion that Will or Tim deliberately defrauded investors or otherwise consciously conspired to rip people off would be false and defamatory.»

OMAR’S DISCLOSURES ERASED MILLIONS, LEAVING HER WITH POTENTIAL NEGATIVE NET WORTH. SHE WON’T EXPLAIN WHY

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The revelation is not new, but it’s one of several details that have resurfaced in recent days amid a federal probe into Omar’s citizenship in the U.S.

Federal law enforcement executed a search warrant at her D.C. home earlier this month. The operation was linked to allegations that she and her father misrepresented the congresswoman’s age to more easily obtain American citizenship.

REP ILHAN OMAR’S IMMIGRATION HISTORY FACES NEW SCRUTINY AS FEDERAL INVESTIGATORS SUBPOENA RELATIVES

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Omar’s critics, like House Majority Whip Tom Emmer, R-Minn., have called for the progressive Democrat to be deported if the allegations were proved true.

She and her allies have denied wrongdoing and attacked the investigation as a partisan hit job against one of President Donald Trump’s most vocal opponents.

But it’s not the first time Omar has faced accusations of impropriety as a member of Congress.

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The House Oversight Committee had earlier probed Omar’s finances after her public disclosures showed a rapid, and at the time unexplained, increase in her net worth. Omar previously chalked up the discrepancy to an accidental accounting error.

Comer zeroed in on the winery in a February letter sent just weeks before the business closed down.

He wrote to Mynett that Omar’s 2023 financial disclosure forms «lists a stake in your winery eStCru worth between $15,001 and $50,000.» The following year, her financial disclosure form listed a stake in eStCru «worth between $1,000,001 and $5,000,000.»

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«There are serious public concerns about how your businesses increased so dramatically in value only a year after reporting very limited assets,» the letter said.

Omar told The Wall Street Journal in mid-April that she and her husband have less than $100,000 combined.

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The winery, eStCru, was based in California and was founded in 2020 by Mynett and a business partner. The industry outlet Wine Business named it one of its «Hot Brands of 2022.»

When asked about the probe, a spokesperson for the House Oversight Committee pointed out to Digital that Comer had referred the case of Omar’s finances to the House Ethics Committee for review.

«Regarding the investigation into her spouse, the House Oversight Committee referred the matter months ago to the House Ethics Committee and encouraged it to do its job and review the concerning allegations,» the spokesperson said.

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The bipartisan panel is tasked with investigating accusations of impropriety by lawmakers and recommending punishments if those probes turn up wrongdoing. It has not yet taken up Omar’s case.

Digital reached out to Rose Lake Capital, another venture by Mynett and his business partner, for comment on Comer’s remarks. 

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Russia releases American teacher imprisoned on Ukraine mercenary charges after Trump pressed Putin

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NEWYou can now listen to Fox News articles!

Russia has freed a retired U.S. teacher who was locked up on charges of fighting as a mercenary in Ukraine, according to U.S. envoy Steve Witkoff.

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The Michigan man, Stephen Hubbard, had been sentenced in 2024 to almost seven years imprisonment.

Prosecutors said he had signed a contract with the Ukrainian military after Russia sent troops into Ukraine in February 2022, and that he fought alongside them until being captured two months later.

A screen set up at a hall of the Moscow City Court broadcasts the verdict announcement in the trial of US citizen Stephen Hubbard, 72, accused of fighting as a mercenary for Ukraine, in Moscow on October 7, 2024.  (NATALIA KOLESNIKOVA/AFP via Getty Images)

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«I’ve been talking to President Putin about Mr. Hubbard. I’ve been talking to him at length. I’ve asked him to release him,» President Donald Trump had said on Tuesday. «Let’s see what happens.»

The Associated Press contributed to this report

This is a breaking news story and will be updated

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Food delivery favorite forced to fork over millions after DOJ alleged discrimination against American workers

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FIRST ON FOX: Popular grocery delivery company Instacart has reached a multimillion-dollar settlement with the Department of Justice (DOJ) after it was accused of discriminating against American workers.

The DOJ’s Civil Rights Division says it has reached a $5 million settlement with Maplebear Inc., which operates the delivery service used by Americans to get groceries sent to their front doors. The resolution addresses allegations that the company purposefully discriminated against U.S. and American workers based on country of origin, which the DOJ says violates the Immigration and Nationality Act (INA) and Title VII of the Civil Rights Act of 1964 (Title VII).

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The company, according to the Justice Department, was abusing the Permanent Labor Certification (PERM) process by placing undue burdens on American applicants by requiring them to physically mail applications to the company, deviating from Instacart’s standard electronic application process. The scheme occurred from December 2023 through February 2026.

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«This significant resolution marks the 15th settlement agreement the Civil Rights Division has reached under my leadership to protect U.S. workers,» Assistant Attorney General Harmeet K. Dhillon said. «Our record demonstrates that the Justice Department is holding companies who prefer workers with temporary employment visas accountable. We will not stop fighting for U.S. workers until there is a fair playing field.»

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The settlement was secured in conjunction with the U.S. Equal Employment Opportunity Commission (EEOC).

Instacart will be required, under the settlement, to set up a $4 million fund to compensate applicants who may have been wronged, and another $1 million in civil penalties.

The PERM program allows employers to sponsor temporary visa workers for permanent residence in the United States. However, companies using the PERM program are required to make a «good-faith» effort to hire American workers before resorting to foreigners.

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STARBUCKS RESOLVES FLORIDA DEI LAWSUIT WITH BLOCKBUSTER AGREEMENT

Companies cannot create «additional burdens for U.S. and American workers; publishing job advertisements that disfavor, limit, specify, or otherwise discriminate against U.S. and American workers; or use processes that limit, segregate, or classify applicants in any way that tends to deprive U.S. and American applicants of employment opportunities,» according to the DOJ.

The settlement is the 15th of its kind since President Donald Trump began his second term in office in January 2025 and is part of a broader effort to ensure American workers aren’t illegally discriminated against.

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The EEOC has dubbed the mission «Project Firewall.»

«Today’s settlement makes clear that when employers erect unlawful barriers that harm American workers, the EEOC will act decisively,» said Andrea Lucas, the chair of the EEOC. «The EEOC is committed to holding companies accountable when they deny equal work opportunities to U.S. workers by preferring temporary visa holders for jobs. Discrimination against workers based on their American national origin has no place in our economy.»

«We’re proud to be a U.S.-based grocery technology platform, employing thousands of American workers and serving millions of customers, retailers, shoppers and brands. We encourage qualified U.S. jobseekers to apply to join our team,» an Instacart spokesperson told Digital.

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«Hiring and investing in American workers across our U.S. business is our priority, and we actively promote every role across many channels to ensure qualified U.S. candidates are always first in line for opportunities. While we maintain that our practices complied with all applicable laws and regulations, we’re pleased to have resolved this matter so we can keep our full focus on delivering on our mission for customers, shoppers, retailers and brands.»

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