tldrdaily.news logo
Tag

Biology

All articles tagged with #biology

Salt cycles drive mixed clonal-aggregative multicellularity in a choanoflagellate
biology16 hours ago

Salt cycles drive mixed clonal-aggregative multicellularity in a choanoflagellate

Researchers show Choanoeca flexa forms multicellular sheets clonally, via aggregation, or through a mix—clonal-aggregative multicellularity—driven by evaporation–refilling salinity cycles in Curaçao splash pools. Low salinity supports both cell division and aggregation to build sheets, while hypersalinity triggers dissociation into desiccation‑resistant cysts that can rehydrate into sheets. Aggregation is active, requires living cells, and exhibits kin recognition and species specificity; density and salinity shift the balance between clonal and aggregative modes. Genomic analyses identify candidate kin‑recognition loci. Together, the findings reveal a flexible, environmentally entrained route to multicellularity, expanding our understanding of choanoflagellate biology and potential premetazoan life histories.

via Nature|
#biology#choanoflagellate#clonal-aggregative
Pre-ZGA 3D genome architecture emerges modularly in Drosophila embryos
biology1 day ago

Pre-ZGA 3D genome architecture emerges modularly in Drosophila embryos

Using Pico-C, a low-input Micro-C method, the study maps high-resolution 3D genome architecture across NC9–NC14 in early Drosophila embryos and reveals that chromatin loops and boundaries emerge in an ordered, modular fashion before major ZGA. Transcriptional elongation inhibition preserves some early loops but weakens promoter insulation, while sequence-based models show orthogonal motif-driven contributions to architecture. Co-depleting Zelda and GAF confirms locus-specific regulatory inputs, supporting a layered regulatory logic for genome establishment prior to ZGA.

via Nature|
#3d-genome#biology#chromatin-architecture
Death-Resistant Cells Drive Regeneration, Linking Wound Repair to Cancer Risk
biology10 days ago

Death-Resistant Cells Drive Regeneration, Linking Wound Repair to Cancer Risk

A Weizmann Institute study reveals that a subset of cells can survive radiation by keeping caspases from completing cell death, called DARE cells, which promote tissue regeneration via compensatory proliferation; their death-resistant descendants may contribute to cancer relapse, but neighboring NARE cells form a negative feedback loop to limit overgrowth.

via SciTechDaily|
#apoptosis#biology#cancer-relapse
Cannibalism in Snakes: Evolutionary Trick Repeats Across 11 Lineages
animals11 days ago

Cannibalism in Snakes: Evolutionary Trick Repeats Across 11 Lineages

A review of 503 cannibalism reports across 207 snake species finds that cannibalistic behavior has evolved independently at least 11 times. The behavior appears across continents and contexts, often linked to environmental stress or scarce food, with many captivity cases; jaw flexibility and dietary generalism help some snakes consume conspecifics. Researchers say cannibalism can provide ecological fitness as an opportunistic feeding strategy, though much of the data are anecdotal and more study is needed.

via Live Science|
#animals#biology#cannibalism
Serine Shortage Reprograms Hair Follicle Stem Cells for Faster Wound Healing
science18 days ago

Serine Shortage Reprograms Hair Follicle Stem Cells for Faster Wound Healing

Rockefeller University researchers found that when serine levels drop, the integrated stress response activates and hair follicle stem cells reduce hair production to prioritize skin repair, speeding wound healing; boosting serine has limited effect due to the body's tight control over its circulation, though restoring serine in cells lacking it can partly rescue hair growth—pointing to diet or drug strategies to modulate serine/ISR for faster healing.

via SciTechDaily|
#biology#metabolism#science
Tiny llama nanobodies lock coronavirus spike to block infection across variants
biology20 days ago

Tiny llama nanobodies lock coronavirus spike to block infection across variants

Researchers identified llama-derived single-domain antibodies (nanobodies) that bind a conserved base region (S2) of the coronavirus spike and act like a clamp, locking the spike in its original shape and preventing the conformational changes needed for cell entry. In animal tests these nanobodies provided strong protection at low doses and showed a high barrier to viral escape, neutralizing a broad range of SARS-related coronaviruses and offering potential for long-lasting antiviral therapies resilient to future variants.

via SciTechDaily|
#biology#broad-neutralization#coronavirus
Fungi weaponize plant defenses to combat bark beetles
science24 days ago

Fungi weaponize plant defenses to combat bark beetles

Researchers from the Max Planck Institute showed that certain Beauveria bassiana strains can infect and kill bark beetles by detoxifying spruce tree defense chemicals (stilbenes and flavonoids). The fungus converts these compounds into less protective forms through two phases, first removing sugar to form aglycones and then methylating them to methylglucosides, which avoids the plant defenses and enables infection. Gene knockouts of the detoxification pathways reduce virulence, indicating these defenses are bypassable. Other fungi, like Cordyceps militaris, may use similar tricks, suggesting a future in biocontrol where fungi replace some chemical insecticides.

via Ars Technica|
#bark-beetles#biology#fungi
Aging Revealed: Two Midlife Turning Points at 44 and 60
science1 month ago

Aging Revealed: Two Midlife Turning Points at 44 and 60

A Stanford-led study analyzing 135,000 molecular markers in 108 people finds aging may occur at two discrete inflection points—around ages 44 and 60—where rapid changes occur in cardiovascular, immune, and metabolic pathways, with microbiome shifts closely linked to these transitions. While causality isn’t established, the results suggest midlife biology could influence disease risk and screening strategies, potentially guiding precision medicine. Limitations include a small, non-diverse sample and observational data; lifestyle factors like stress and alcohol may also play a role in these transitions.

via The Daily Galaxy|
#aging#biology#microbiome
Embryo Cell Division Driven by Mechanical Ratchet, Not a Full Contractile Ring
biology1 month ago

Embryo Cell Division Driven by Mechanical Ratchet, Not a Full Contractile Ring

Researchers from the Brugués group at TU Dresden report in Nature a new mechanism for early embryonic cell division in yolk-rich cells: a mechanical ratchet that drives division without a fully closed actin contractile ring. By showing microtubule asters stiffen the cytoplasm during interphase and the cytoplasm becomes more fluid in M-phase, they find the actin band can ingress across multiple cell cycles, anchored by microtubules and re-stabilized when the cytoplasm stiffens again. This challenges textbook models and may apply broadly to yolk-rich embryos across species.

via SciTechDaily|
#biology#cell-division#cytokinesis