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Genome-Wide Variation Profile of the Genus Tobamovirus

The genus Tobamovirus belongs to the family Virgaviridae, and the genome consists of monopartite, positive, single-strand RNA. Most species contain four open reading frames encoding four essential proteins. Transmission occurs primarily through mechanical contact between plants, and in some cases, via seed dispersal. Tobamovirus fructirugosum (tomato brown rugose fruit virus, ToBRFV), the most recently described species in the genus, was first reported in 2015. It overcame genetic resistance that had been effective in tomato for sixty years, causing devastating losses in tomato production worldwide, and highlights the importance of understanding Tobamovirus genomic variation and evolution. In this study, we measured and characterized nucleotide variation for the entire genome and for all species in the genus Tobamovirus.

A new attempt to explain the accelerated expansion of the universe

Why is the universe expanding at an ever-increasing rate? This is one of the most exciting yet unresolved questions in modern physics. Because it cannot be fully answered using our current physical worldview, researchers assume the existence of a mysterious “dark energy.” However, its origin remains unclear to this day.

An international research team from the Center for Applied Space Technology and Microgravity (ZARM) at the University of Bremen and the Transylvanian University of Brașov in Romania has come to the conclusion that the expansion of the universe can be explained—at least in part—without dark energy.

In physics, the evolution of the universe has so far been described by the and the so-called Friedmann equations. However, in order to explain the observed expansion of the universe on this basis, an additional “dark energy term” must be manually added to the equations.

Gaia provides a deep look into the galactic open cluster NGC 2506

Using ESA’s Gaia satellite and NASA’s Transiting Exoplanet Survey Satellite (TESS), astronomers from the Ege University in Turkey and elsewhere have observed a galactic open cluster known as NGC 2506. Results of the observational campaign, published October 7 on the arXiv pre-print server, put more constraints on the properties of this cluster.

In general, groups of stars formed from the same giant molecular cloud and loosely gravitationally bound to each other are known as open clusters (OCs). Inspecting galactic OCs in detail could be crucial for improving our understanding of the formation and evolution of our Milky Way galaxy.

NGC 2,506 is a mildly-elongated OC estimated to be located some 12,700 light years away, near the galactic anti-center. It is a well-populated, metal-poor, intermediate-age cluster with a radius of about 18.5 light years.

SCP-3812: The Entity That Broke Reality | The Science of a God Who Knows It’s Fiction

What happens when awareness grows too powerful for the universe that contains it?

SCP-3812 — also known as A Voice Behind Me — is the Foundation’s ultimate paradox: a being that rewrites existence every time it tries to understand itself. This speculative science essay explores the physics, metaphysics, and philosophy behind the phenomenon. From quantum observer effects to pancomputational cosmology, from the breakdown of time to the collapse of narrative itself, we ask the ultimate question:

What if consciousness doesn’t live inside reality, but creates it?

Join us as we explore:

- The origin of Sam Howell and post-mortem evolution of awareness.
- The science of unreality and the hierarchy of dimensions.
- Schizophrenia as multiversal cognition.
- Supersession, recursion, and the limits of containment.
- The final collapse of reality into pure perception.

If you love speculative science, existential philosophy, or cosmic horror wrapped in logic, this video will change the way you think about reality.

Astronomers uncover collisional signature of filamentary structures in galactic G34 molecular cloud

Using CO (J=1–0) molecular line data obtained from the 13.7-meter millimeter-wave telescope at the Purple Mountain Observatory’s Delingha Observatory, Sun Mingke, a Ph.D. student from the Xinjiang Astronomical Observatory of the Chinese Academy of Sciences and his collaborators conducted a systematic study of the galactic molecular cloud G34. They revealed the collisional signatures and dynamical mechanisms of filamentary structures in this region. The results are published in Astronomy & Astrophysics.

Star formation is one of the key processes that drive the evolution of galaxies and the . Recent observations and suggest that interactions and collisions between large-scale filamentary structures may play an important role in triggering high-mass .

In this study, the researchers identified two giant filaments, designated F1 and F2, in the G34 region. By analyzing their and velocity field, the researchers found clear evidence of ongoing collisions between the filaments.

Analysis of genomic heterogeneity and the mutational landscape in cutaneous squamous cell carcinoma through multi-patient-targeted single-cell DNA sequencing

Cutaneous squamous cell carcinoma (CSCC) is a prevalent skin cancer with aggressive progression that poses significant challenges, especially in metastatic cases. Single-cell DNA sequencing (scDNA-seq) has become an advanced technology for elucidating tumor heterogeneity and clonal evolution. However, comprehensive scDNA-seq studies and tailored mutation panels for CSCC are lacking.

We analyzed the genomic landscape of Chinese CSCC patients via a Multi-Patient-Targeted (MPT) scDNA-seq approach. This method combined bulk exome sequencing with Tapestri scDNA-seq. Mutations identified through bulk sequencing were used to design a targeted panel for scDNA-seq. Comparative analysis was conducted to explore the associations between specific gene mutations and clinical characteristics such as tumor stage and patient sex. Clonal evolution analysis was performed to understand the evolutionary trajectories of the tumors.

Bulk sequencing revealed a diverse spectrum of somatic mutations in CSCC tumors, with missense mutations being predominant. The top tumor mutations, such as those in NOTCH1, TP53, NOTCH2, TTN, MUC16, RYR2, PRUNE2, DMD, HRAS, and CDKN2A, presented similar frequencies to those reported in studies in Korean and Caucasian populations. However, the mutation frequencies of HRAS, TTN, MUC16 and MUC4 were significantly different from the Korean and Caucasian populations. Comparative analysis revealed associations between specific gene mutations and clinical characteristics such as tumor stage and patient sex. Clonal evolution analysis via scDNA-seq revealed distinct evolutionary trajectories and their potential correlation with tumor development and patient prognosis. Furthermore, scDNA-seq identified two low-frequency mutation clones, NLRP5 and HMMR, which play important roles in the clonal evolution of CSCC.

P53 in the DNA-Damage-Repair Process

The cells in the human body are continuously challenged by a variety of genotoxic attacks. Erroneous repair of the DNA can lead to mutations and chromosomal aberrations that can alter the functions of tumor suppressor genes or oncogenes, thus causing cancer development. As a central tumor suppressor, p53 guards the genome by orchestrating a variety of DNA-damage-response (DDR) mechanisms. Already early in metazoan evolution, p53 started controlling the apoptotic demise of genomically compromised cells. p53 plays a prominent role as a facilitator of DNA repair by halting the cell cycle to allow time for the repair machineries to restore genome stability. In addition, p53 took on diverse roles to also directly impact the activity of various DNA-repair systems. It thus appears as if p53 is multitasking in providing protection from cancer development by maintaining genome stability.

A cGAS-mediated mechanism in naked mole-rats potentiates DNA repair and delays aging

Efficient DNA repair might make possible the longevity of naked mole-rats. However, whether they have distinctive mechanisms to optimize functions of DNA repair suppressors is unclear. We find that naked mole-rat cyclic guanosine monophosphate–adenosine monophosphate synthase (cGAS) lacks the suppressive function of human or mouse homologs in homologous recombination repair through the alteration of four amino acids during evolution. The changes enable cGAS to retain chromatin longer upon DNA damage by weakening TRIM41-mediated ubiquitination and interaction with the segregase P97. Prolonged chromatin binding of cGAS enhanced the interaction between repair factors FANCI and RAD50 to facilitate RAD50 recruitment to damage sites, thereby potentiating homologous recombination repair.

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