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1.
Nano Lett ; 2024 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-39319575

RESUMEN

Electrophysiological recordings from brain cells are performed routinely using implanted electrodes, but they traditionally require a wired connection to the outside of the brain. A completely passive, wireless device that does not require on-board power for active transmission but that still facilitates remote detection could open the door for mass-scale direct recording of action potentials and transform the way we acquire brain signals. We present a nanofabricated coil that forms a neuroelectromagnetic junction, yielding a highly enhanced magnetic field transduction of electrophysiology. We show that this micrometer-scale device enables remote magnetic detection of neuronal fields from the center of the coil using room temperature superconducting quantum interference device (SQUID) microscopy. Further, time-locked stimulation in conjunction with magnetometry demonstrates thresholding behavior that affirms the viability of the technology for detection with no requirement for wires or on-board power. This strategy may permit unprecedented detection of electrophysiology using magnetoencephalography and magnetic resonance imaging.

2.
Sci Adv ; 10(39): eadm8241, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39321302

RESUMEN

A major objective of the Mars 2020 mission is to sample rocks in Jezero crater that may preserve organic matter for later return to Earth. Using an ultraviolet Raman and luminescence spectrometer, the Perseverance rover detected luminescence signals with maximal intensities at 330 to 350 nanometers and 270 to 290 nanometers that were initially reported as consistent with organics. Here, we test the alternative hypothesis that the 330- to 350-nanometer and 270- to 290-nanometer luminescence signals trace Ce3+ in phosphate and silicate defects, respectively. By comparing the distributions of luminescence signals with the rover detections of x-ray fluorescence from P2O5 and Si-bearing materials, we show that, while an organic origin is not excluded, the observed luminescence can be explained by purely inorganic materials. These findings highlight the importance of eventual laboratory analyses to detect and characterize organic compounds in the returned samples.

3.
Commun Biol ; 7(1): 981, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39134630

RESUMEN

Neuropteran larvae are fierce predators that use venom to attack and feed on arthropod prey. Neuropterans have adapted to diverse and sometimes extreme habitats, suggesting their venom may have evolved accordingly, but the ecology and evolution of venom deployment in different families is poorly understood. We applied spatial transcriptomics, proteomics, morphological analysis, and bioassays to investigate the venom systems in the antlion Euroleon nostras and the lacewing Chrysoperla carnea, which occupy distinct niches. Although the venom system morphology was similar in both species, we observed remarkable differences at the molecular level. E. nostras produces particularly complex venom secreted from three different glands, indicating functional compartmentalization. Furthermore, E. nostras venom and digestive tissues were devoid of bacteria, strongly suggesting that all venom proteins are of insect origin rather than the products of bacterial symbionts. We identified several toxins exclusive to E. nostras venom, including phospholipase A2 and several undescribed proteins with no homologs in the C. carnea genome. The compositional differences have significant ecological implications because only antlion venom conferred insecticidal activity, indicating its use for the immobilization of large prey. Our results indicate that molecular venom evolution plays a role in the adaptation of antlions to their unique ecological niche.


Asunto(s)
Venenos de Artrópodos , Conducta Predatoria , Animales , Venenos de Artrópodos/metabolismo , Venenos de Artrópodos/genética , Ecosistema , Insectos/fisiología , Larva/fisiología , Proteómica , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Transcriptoma
4.
ISME J ; 18(1)2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38874172

RESUMEN

Insects engage in manifold interactions with bacteria that can shift along the parasitism-mutualism continuum. However, only a small number of bacterial taxa managed to successfully colonize a wide diversity of insects, by evolving mechanisms for host-cell entry, immune evasion, germline tropism, reproductive manipulation, and/or by providing benefits to the host that stabilize the symbiotic association. Here, we report on the discovery of an Enterobacterales endosymbiont (Symbiodolus, type species Symbiodolus clandestinus) that is widespread across at least six insect orders and occurs at high prevalence within host populations. Fluorescence in situ hybridization in several Coleopteran and one Dipteran species revealed Symbiodolus' intracellular presence in all host life stages and across tissues, with a high abundance in female ovaries, indicating transovarial vertical transmission. Symbiont genome sequencing across 16 host taxa revealed a high degree of functional conservation in the eroding and transposon-rich genomes. All sequenced Symbiodolus genomes encode for multiple secretion systems, alongside effectors and toxin-antitoxin systems, which likely facilitate host-cell entry and interactions with the host. However, Symbiodolus-infected insects show no obvious signs of disease, and biosynthetic pathways for several amino acids and cofactors encoded by the bacterial genomes suggest that the symbionts may also be able to provide benefits to the hosts. A lack of host-symbiont cospeciation provides evidence for occasional horizontal transmission, so Symbiodolus' success is likely based on a mixed transmission mode. Our findings uncover a hitherto undescribed and widespread insect endosymbiont that may present valuable opportunities to unravel the molecular underpinnings of symbiosis establishment and maintenance.


Asunto(s)
Enterobacteriaceae , Insectos , Simbiosis , Animales , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Enterobacteriaceae/clasificación , Femenino , Insectos/microbiología , Hibridación Fluorescente in Situ , Genoma Bacteriano , Filogenia
5.
J Endovasc Ther ; : 15266028241258659, 2024 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-38880997

RESUMEN

PURPOSE: The aim of this study was to present the covered endovascular reconstruction of the iliac artery bifurcation (CERIB) technique as a revascularization option for aorto-iliac occlusive disease (AIOD) involving the iliac artery bifurcation. METHODS: This was a retrospective single-center study including all patients undergoing a CERIB procedure from January 2021 until December 2022. Covered endovascular reconstruction of the iliac artery bifurcation procedures were performed percutaneously with bilateral femoral access, excepting cases where simultaneous open femoral artery reconstruction was required due to the extension of peripheral arterial occlusive disease. Standard patient, procedural, and follow-up (FU) data including survival and arterial reinterventions were gathered and analyzed. RESULTS: A total of 13 patients were included (11/13 male, median age=70 [60-76] years). Additional open and/or endovascular procedures included endarterectomy of the femoral bifurcation (n=6), rotational atherectomy (n=2), and 1 axillary artery cutdown for upper limb access (n=1). Median operating time was 2.9 hours (1.5-4.9 hours); median radiation duration and dose were 28.4 (14.3-63.3 minutes) and 4090.6 (384.4-9430.1 cGray/cm2), respectively. The stent grafts used for CERIB were BeGraft peripheral n=31, BeGraft Aortic n=4 and BeGraft peripheral plus n=1 (Bentley InnoMed GmbH, Hechingen, Germany). In 2 patients with prior stenting of the common iliac artery (CIA), only the internal and external iliac arteries (IIA and EIA) were treated in this study, and in 2 cases, additional uncovered stents were required for relining. Technical success was 100%. During a midterm FU (median 18 [4-31] months), 2 patients died from cardiovascular reasons and 1 patient with prior iliac stenting required reinterventions for recurring occlusion. CONCLUSION: Covered endovascular reconstruction of the iliac artery bifurcation is a straightforward option for treating AIOD involving the iliac artery bifurcation that allows preservation of internal iliac artery perfusion and shows good early and midterm results. Prior iliac artery stenting may be a risk factor for early occlusion after CERIB. CLINICAL IMPACT: Aorto-iliac occlusive disease with involvement of the internal iliac artery is encountered regularly in vascular surgical practice, but the internal iliac artery is often not included in the revascularization strategy. The present article will increase the awareness for the relevance of including the internal iliac artery in revascularization strategies and presents CERIB as another method to be added to the armamentarium of (endo-)vascular surgeons and interventionalists.

6.
Cell Rep ; 43(5): 114126, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38630588

RESUMEN

Scanning and initiation are critical steps in translation. Here, we utilized translation complex profiling (TCP-seq) to investigate 48S organization and eIF4G1-eIF1 inhibition impact. We provide global views of scanning and leaky scanning, uncovering a central role of eIF4G1-eIF1 in their regulation. We confirm AUG context importance, with non-leaky genes featuring a Kozak context and cytosine at positions -1 and +5. Capturing 48S complexes associated with eIF1, eIF4G1, eIF3, and eIF2 through selective TCP-seq revealed that the eIF3-scanning ribosome is highly vulnerable to eIF4G1-eIF1 inhibition, and eIF1 tends to dissociate upon AUG recognition. Initiation-site footprint analysis revealed a class spanning -12 to +18/19 from the AUG, representing the entire 48S and enriched with eIF2, eIF1, and eIF4G1, indicative of early initiation. Another eIF3-dependent class extends up to +26 and exhibits reduced eIF2 and eIF4G1 association, suggesting a late/alternative initiation complex. Our analysis provides an overview of scanning, initiation, and evidence for conformational rearrangements in vivo.


Asunto(s)
Ribosomas , Ribosomas/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Iniciación de la Cadena Peptídica Traduccional , Humanos , Factor 4G Eucariótico de Iniciación/metabolismo , Factor 4G Eucariótico de Iniciación/genética , Biosíntesis de Proteínas , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
7.
ISME Commun ; 4(1): ycae005, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38439943

RESUMEN

Insects typically acquire their beneficial microbes early in development. Endosymbionts housed intracellularly are commonly integrated during oogenesis or embryogenesis, whereas extracellular microbes are only known to be acquired after hatching by immature instars such as larvae or nymphs. Here, however, we report on an extracellular symbiont that colonizes its host during embryo development. Tortoise beetles (Chrysomelidae: Cassidinae) host their digestive bacterial symbiont Stammera extracellularly within foregut symbiotic organs and in ovary-associated glands to ensure its vertical transmission. We outline the initial stages of symbiont colonization and observe that although the foregut symbiotic organs develop 3 days prior to larval emergence, they remain empty until the final 24 h of embryo development. Infection by Stammera occurs during that timeframe and prior to hatching. By experimentally manipulating symbiont availability to embryos in the egg, we describe a 12-h developmental window governing colonization by Stammera. Symbiotic organs form normally in aposymbiotic larvae, demonstrating that these Stammera-bearing structures develop autonomously. In adults, the foregut symbiotic organs are already colonized following metamorphosis and host a stable Stammera population to facilitate folivory. The ovary-associated glands, however, initially lack Stammera. Symbiont abundance subsequently increases within these transmission organs, thereby ensuring sufficient titers at the onset of oviposition ~29 days following metamorphosis. Collectively, our findings reveal that Stammera colonization precedes larval emergence, where its proliferation is eventually decoupled in adult beetles to match the nutritional and reproductive requirements of its host.

8.
Sci Rep ; 14(1): 7175, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38532041

RESUMEN

The Mars Sample Return mission intends to retrieve a sealed collection of rocks, regolith, and atmosphere sampled from Jezero Crater, Mars, by the NASA Perseverance rover mission. For all life-related research, it is necessary to evaluate water availability in the samples and on Mars. Within the first Martian year, Perseverance has acquired an estimated total mass of 355 g of rocks and regolith, and 38 µmoles of Martian atmospheric gas. Using in-situ observations acquired by the Perseverance rover, we show that the present-day environmental conditions at Jezero allow for the hydration of sulfates, chlorides, and perchlorates and the occasional formation of frost as well as a diurnal atmospheric-surface water exchange of 0.5-10 g water per m2 (assuming a well-mixed atmosphere). At night, when the temperature drops below 190 K, the surface water activity can exceed 0.5, the lowest limit for cell reproduction. During the day, when the temperature is above the cell replication limit of 245 K, water activity is less than 0.02. The environmental conditions at the surface of Jezero Crater, where these samples were acquired, are incompatible with the cell replication limits currently known on Earth.

9.
R Soc Open Sci ; 11(3): 231514, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38481984

RESUMEN

Coral reefs, hubs of global biodiversity, are among the world's most imperilled habitats. Healthy coral reefs are characterized by distinctive soundscapes; these environments are rich with sounds produced by fishes and marine invertebrates. Emerging evidence suggests these sounds can be used as orientation and settlement cues for larvae of reef animals. On degraded reefs, these cues may be reduced or absent, impeding the success of larval settlement, which is an essential process for the maintenance and replenishment of reef populations. Here, in a field-based study, we evaluated the effects of enriching the soundscape of a degraded coral reef to increase coral settlement rates. Porites astreoides larvae were exposed to reef sounds using a custom solar-powered acoustic playback system. Porites astreoides settled at significantly higher rates at the acoustically enriched sites, averaging 1.7 times (up to maximum of seven times) more settlement compared with control reef sites without acoustic enrichment. Settlement rates decreased with distance from the speaker but remained higher than control levels at least 30 m from the sound source. These results reveal that acoustic enrichment can facilitate coral larval settlement at reasonable distances, offering a promising new method for scientists, managers and restoration practitioners to rebuild coral reefs.

10.
EMBO Mol Med ; 16(3): 523-546, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38374466

RESUMEN

Huntington's disease (HD) is an incurable inherited disorder caused by a repeated expansion of glutamines in the huntingtin gene (Htt). The mutant protein causes neuronal degeneration leading to severe motor and psychological symptoms. Selective downregulation of the mutant Htt gene expression is considered the most promising therapeutic approach for HD. We report the identification of small molecule inhibitors of Spt5-Pol II, SPI-24 and SPI-77, which selectively lower mutant Htt mRNA and protein levels in HD cells. In the BACHD mouse model, their direct delivery to the striatum diminished mutant Htt levels, ameliorated mitochondrial dysfunction, restored BDNF expression, and improved motor and anxiety-like phenotypes. Pharmacokinetic studies revealed that these SPIs pass the blood-brain-barrier. Prolonged subcutaneous injection or oral administration to early-stage mice significantly delayed disease deterioration. SPI-24 long-term treatment had no side effects or global changes in gene expression. Thus, lowering mutant Htt levels by small molecules can be an effective therapeutic strategy for HD.


Asunto(s)
Enfermedad de Huntington , Animales , Ratones , Encéfalo/metabolismo , Cuerpo Estriado , Modelos Animales de Enfermedad , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Enfermedad de Huntington/tratamiento farmacológico , Enfermedad de Huntington/genética , Fenotipo , ARN Mensajero/genética
11.
Space Sci Rev ; 219(4): 34, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37251605

RESUMEN

The goal of NASA's Europa Clipper Mission is to investigate the habitability of the subsurface ocean within the Jovian moon Europa using a suite of ten investigations. The Europa Clipper Magnetometer (ECM) and Plasma Instrument for Magnetic Sounding (PIMS) investigations will be used in unison to characterize the thickness and electrical conductivity of Europa's subsurface ocean and the thickness of the ice shell by sensing the induced magnetic field, driven by the strong time-varying magnetic field of the Jovian environment. However, these measurements will be obscured by the magnetic field originating from the Europa Clipper spacecraft. In this work, a magnetic field model of the Europa Clipper spacecraft is presented, characterized with over 260 individual magnetic sources comprising various ferromagnetic and soft-magnetic materials, compensation magnets, solenoids, and dynamic electrical currents flowing within the spacecraft. This model is used to evaluate the magnetic field at arbitrary points around the spacecraft, notably at the locations of the three fluxgate magnetometer sensors and four Faraday cups which make up ECM and PIMS, respectively. The model is also used to evaluate the magnetic field uncertainty at these locations via a Monte Carlo approach. Furthermore, both linear and non-linear gradiometry fitting methods are presented to demonstrate the ability to reliably disentangle the spacecraft field from the ambient using an array of three fluxgate magnetometer sensors mounted along an 8.5-meter (m) long boom. The method is also shown to be useful for optimizing the locations of the magnetometer sensors along the boom. Finally, we illustrate how the model can be used to visualize the magnetic field lines of the spacecraft, thus providing very insightful information for each investigation. Supplementary Information: The online version contains supplementary material available at 10.1007/s11214-023-00974-y.

12.
Space Sci Rev ; 219(3): 22, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37007705

RESUMEN

The objective of the Psyche Magnetometry Investigation is to test the hypothesis that asteroid (16) Psyche formed from the core of a differentiated planetesimal. To address this, the Psyche Magnetometer will measure the magnetic field around the asteroid to search for evidence of remanent magnetization. Paleomagnetic measurements of meteorites and dynamo theory indicate that a diversity of planetesimals once generated dynamo magnetic fields in their metallic cores. Likewise, the detection of a strong magnetic moment ( > 2 × 10 14 Am 2 ) at Psyche would likely indicate that the body once generated a core dynamo, implying that it formed by igneous differentiation. The Psyche Magnetometer consists of two three-axis fluxgate Sensor Units (SUs) mounted 0.7 m apart along a 2.15-m long boom and connected to two Electronics Units (EUs) located within the spacecraft bus. The Magnetometer samples at up to 50 Hz, has a range of ± 80 , 000 nT , and an instrument noise of 39 pT axis - 1 3 σ integrated over 0.1 to 1 Hz. The two pairs of SUs and EUs provide redundancy and enable gradiometry measurements to suppress noise from flight system magnetic fields. The Magnetometer will be powered on soon after launch and acquire data for the full duration of the mission. The ground data system processes the Magnetometer measurements to obtain an estimate of Psyche's dipole moment.

13.
Space Sci Rev ; 219(3): 25, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37034007

RESUMEN

The NASA Psyche mission's program to engage university undergraduates and the public in the mission is inspired by and built upon the extensive foundation of public engagement, educational outreach activities, and expertise of NASA and mission partner institutions. The program leverages the enthusiasm and contributions of undergraduates nationwide to the benefit of the mission, the students and their institutions and communities, and the broader public. Psyche Student Collaborations consists of four main programs, two (Psyche Capstone and Psyche Inspired) are available solely to undergraduates enrolled at universities or community colleges in the United States and its territories and two (Innovation Toolkit free online courses and Science Outreach Interns and Docents) invite broader participation by engaging the talents and creativity of undergraduate interns to help create content and events to reach the public and lifelong learners. Together, these offerings provide multiple entry points and a spectrum of intensity of experiences, numbers of participants, disciplinary diversity, and mode of delivery. Involving undergraduates in all phases of the program supports the development of the next generation of explorers, contributes to the nation's workforce preparation, and complements NASA's existing undergraduate offerings by providing long-term opportunities for students to participate with the mission through established postsecondary education structures like capstone courses.

14.
J Geophys Res Planets ; 128(1): e2022JE007432, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37034459

RESUMEN

The five large moons of Uranus are important targets for future spacecraft missions. To motivate and inform the exploration of these moons, we model their internal evolution, present-day physical structures, and geochemical and geophysical signatures that may be measured by spacecraft. We predict that if the moons preserved liquid until present, it is likely in the form of residual oceans less than 30 km thick in Ariel, Umbriel, and less than 50 km in Titania, and Oberon. The preservation of liquid strongly depends on material properties and, potentially, on dynamical circumstances that are presently unknown. Miranda is unlikely to host liquid at present unless it experienced tidal heating a few tens of million years ago. We find that since the thin residual layers may be hypersaline, their induced magnetic fields could be detectable by future spacecraft-based magnetometers. However, if the ocean is maintained primarily by ammonia, and thus well below the water freezing point, then its electrical conductivity may be too small to be detectable by spacecraft. Lastly, our calculated tidal Love number (k 2) and dissipation factor (Q) are consistent with the Q/k 2 values previously inferred from dynamical evolution models. In particular, we find that the low Q/k 2 estimated for Titania supports the hypothesis that Titania currently holds an ocean.

15.
Genome Biol ; 24(1): 30, 2023 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-36803582

RESUMEN

BACKGROUND: The Ccr4-Not complex is mostly known as the major eukaryotic deadenylase. However, several studies have uncovered roles of the complex, in particular of the Not subunits, unrelated to deadenylation and relevant for translation. In particular, the existence of Not condensates that regulate translation elongation dynamics has been reported. Typical studies that evaluate translation efficiency rely on soluble extracts obtained after the disruption of cells and ribosome profiling. Yet cellular mRNAs in condensates can be actively translated and may not be present in such extracts. RESULTS: In this work, by analyzing soluble and insoluble mRNA decay intermediates in yeast, we determine that insoluble mRNAs are enriched for ribosomes dwelling at non-optimal codons compared to soluble mRNAs. mRNA decay is higher for soluble RNAs, but the proportion of co-translational degradation relative to the overall mRNA decay is higher for insoluble mRNAs. We show that depletion of Not1 and Not4 inversely impacts mRNA solubilities and, for soluble mRNAs, ribosome dwelling according to codon optimality. Depletion of Not4 solubilizes mRNAs with lower non-optimal codon content and higher expression that are rendered insoluble by Not1 depletion. By contrast, depletion of Not1 solubilizes mitochondrial mRNAs, which are rendered insoluble upon Not4 depletion. CONCLUSIONS: Our results reveal that mRNA solubility defines the dynamics of co-translation events and is oppositely regulated by Not1 and Not4, a mechanism that we additionally determine may already be set by Not1 promoter association in the nucleus.


Asunto(s)
Ribosomas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Codón/metabolismo , Biosíntesis de Proteínas , Ribosomas/metabolismo , Estabilidad del ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Solubilidad , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
16.
Sci Adv ; 9(1): eadd1511, 2023 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-36608136

RESUMEN

A potential record of Earth's magnetic field going back 4.2 billion years (Ga) ago is carried by magnetite inclusions in zircon grains from the Jack Hills. This magnetite may be secondary in nature, however, meaning that the magnetic record is much younger than the zircon crystallization age. Here, we use atom probe tomography to show that Pb-bearing nanoclusters in magnetite-bearing Jack Hills zircons formed during two discrete events at 3.4 and <2 Ga. The older population of clusters contains no detectable Fe, whereas roughly half of the younger population of clusters is Fe bearing. This result shows that the Fe required to form secondary magnetite entered the zircon sometime after 3.4 Ga and that remobilization of Pb and Fe during an annealing event occurred more than 1 Ga after deposition of the Jack Hills sediment at 3 Ga. The ability to date Fe mobility linked to secondary magnetite formation provides new possibilities to improve our knowledge of the Archean geodynamo.

17.
Int J Mol Sci ; 23(21)2022 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-36362157

RESUMEN

The first step in translation initiation consists in the recruitment of the small ribosome onto the mRNA. This preinitiation complex (PIC) loads via interactions with eIF4F that has assembled on the 5' cap. It then scans the 5' TL (transcript leader) to locate a start site. The molecular architecture of the PIC-mRNA complex over the cap is beginning to be resolved. As part of this, we have been examining the role of the 5' TL length. We observed in vivo initiation events on AUG codons positioned within 3 nts of the 5' cap and robust initiation in vitro at start sites immediately downstream of the 5' end. Ribosomal toe-printing confirmed the positioning of these codons within the P site, indicating that the ribosome reads from the +1 position. To explore differences in the eIF4E-5' cap interaction in the context of long versus short TL, we followed the fate of the eIF4E-cap interaction using a novel solid phase in vitro expression assay. We observed that ribosome recruitment onto a short TL disrupts the eIF4E-cap contact releasing all the mRNA from the solid phase, whereas with a long the mRNA distributes between both phases. These results are discussed in the context of current recruitment models.


Asunto(s)
Factor 4E Eucariótico de Iniciación , Ribosomas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor 4E Eucariótico de Iniciación/genética , Ribosomas/genética , Ribosomas/metabolismo , Factor 4F Eucariótico de Iniciación/metabolismo , Biosíntesis de Proteínas , Caperuzas de ARN/metabolismo
18.
Sci Adv ; 8(47): eabo4856, 2022 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-36417517

RESUMEN

Perseverance's Mastcam-Z instrument provides high-resolution stereo and multispectral images with a unique combination of spatial resolution, spatial coverage, and wavelength coverage along the rover's traverse in Jezero crater, Mars. Images reveal rocks consistent with an igneous (including volcanic and/or volcaniclastic) and/or impactite origin and limited aqueous alteration, including polygonally fractured rocks with weathered coatings; massive boulder-forming bedrock consisting of mafic silicates, ferric oxides, and/or iron-bearing alteration minerals; and coarsely layered outcrops dominated by olivine. Pyroxene dominates the iron-bearing mineralogy in the fine-grained regolith, while olivine dominates the coarse-grained regolith. Solar and atmospheric imaging observations show significant intra- and intersol variations in dust optical depth and water ice clouds, as well as unique examples of boundary layer vortex action from both natural (dust devil) and Ingenuity helicopter-induced dust lifting. High-resolution stereo imaging also provides geologic context for rover operations, other instrument observations, and sample selection, characterization, and confirmation.

19.
Front Physiol ; 13: 979200, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36111144

RESUMEN

The diversity and success of holometabolous insects is partly driven by metamorphosis, which allows for the exploitation of different niches and decouples growth and tissue differentiation from reproduction. Despite its benefits, metamorphosis comes with the cost of temporal vulnerability during pupation and challenges associated with tissue reorganizations. These rearrangements can also affect the presence, abundance, and localization of beneficial microbes in the host. However, how symbionts are maintained or translocated during metamorphosis and which adaptations are necessary from each partner during this process remains unknown for the vast majority of symbiotic systems. Here, we show that Lagria beetles circumvent the constraints of metamorphosis by maintaining defensive symbionts on the surface in specialized cuticular structures. The symbionts are present in both sexes throughout larval development and during the pupal phase, in line with a protective role during the beetle's immature stages. By comparing symbiont titer and morphology of the cuticular structures between sexes using qPCR, fluorescence in situ hybridization, and micro-computed tomography, we found that the organs likely play an important role as a symbiont reservoir for transmission to female adults, since symbiont titers and structures are reduced in male pupae. Using symbiont-sized fluorescent beads, we demonstrate transfer from the region of the dorsal symbiont-housing organs to the opening of the reproductive tract of adult females, suggesting that symbiont relocation on the outer surface is possible, even without specialized symbiont adaptations or motility. Our results illustrate a strategy for holometabolous insects to cope with the challenge of symbiont maintenance during metamorphosis via an external route, circumventing problems associated with internal tissue reorganization. Thereby, Lagria beetles keep a tight relationship with their beneficial partners during growth and metamorphosis.

20.
Proc Natl Acad Sci U S A ; 119(30): e2120339119, 2022 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-35857873

RESUMEN

During translation initiation, eIF4G1 dynamically interacts with eIF4E and eIF1. While the role of eIF4E-eIF4G1 is well established, the regulatory functions of eIF4G1-eIF1 are poorly understood. Here, we report the identification of the eIF4G1-eIF1 inhibitors i14G1-10 and i14G1-12. i14G1s directly bind eIF4G1 and inhibit translation in vitro and in the cell, and their effects on translation are dependent on eIF4G1 levels. Translatome analyses revealed that i14G1s mimic eIF1 and eIF4G1 perturbations on the stringency of start codon selection and the opposing roles of eIF1-eIF4G1 in scanning-dependent and scanning-independent short 5' untranslated region (UTR) translation. Remarkably, i14G1s activate ER/unfolded protein response (UPR) stress-response genes via enhanced ribosome loading, elevated 5'UTR translation at near-cognate AUGs, and unexpected concomitant up-regulation of coding-region translation. These effects are, at least in part, independent of eIF2α-phosphorylation. Interestingly, eIF4G1-eIF1 interaction itself is negatively regulated by ER stress and mTOR inhibition. Thus, i14G1s uncover an unknown mechanism of ER/UPR translational stress response and are valuable research tools and potential drugs against diseases exhibiting dysregulated translation.


Asunto(s)
Estrés del Retículo Endoplásmico , Factor 2 Eucariótico de Iniciación , Factor 4G Eucariótico de Iniciación , Factores Eucarióticos de Iniciación , Proteínas de Neoplasias , Proteínas del Tejido Nervioso , Respuesta de Proteína Desplegada , Animales , Codón Iniciador , Estrés del Retículo Endoplásmico/genética , Factor 2 Eucariótico de Iniciación/metabolismo , Factor 4G Eucariótico de Iniciación/antagonistas & inhibidores , Factor 4G Eucariótico de Iniciación/metabolismo , Factores Eucarióticos de Iniciación/antagonistas & inhibidores , Factores Eucarióticos de Iniciación/metabolismo , Humanos , Ratones , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/metabolismo , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Proteínas del Tejido Nervioso/metabolismo , Fosforilación , Biosíntesis de Proteínas , Respuesta de Proteína Desplegada/genética
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