Decoding Van der Waals Impact on Chirality Transfer in Perovskite Structures: Density Functional Theory Insights.

Chiral organic-inorganic perovskites exhibit unique physicochemical properties driven by the symmetry of monovalent organic cations. However, an atomistic understanding of how chiral cations transfer their chirality to the inorganic framework and the role played by van der Waals (vdW) interactions in this process is still incomplete. In this work, we report a theoretical investigation, based on density functional theory calculations within the Perdew-Burke-Ernzerhof (PBE) formulation for the exchange-correlation functional, into the role of the vdW interactions in the chirality transfer process. For that, we selected several vdW corrections, namely, Grimme (D2, D3, D3(BJ)), Tkatchenko-Scheffler (TS, TS+SCS, TS+HSI), density-dependent energy correction (dDsC), and many-body scattering (MBD) energy method correction. For the chiral perovskite systems, we selected a set of chiral organic-inorganic perovskites with several dimensions, namely, from zero-dimensional to three-dimensional, each having enantiomers with R and S configurations. Based on a statistical treatment of the relative errors of all lattice parameters with respect to experimental data, we found that D3, D3(BJ), TS, TS+SCS, TS+HSI, and MBD vdW are the most accurate corrections to describe the equilibrium structural properties of chiral perovskites using the PBE method. We identify chirality-induced sequential asymmetries of distorted octahedrons and propose angular descriptors to quantify them, where the orientations of these distortions depend on the R or S nature of the chiral cations. Furthermore, we demonstrate the importance of accurate vdW interactions in precisely describing these asymmetric distortions. By means of binding energies and charge-transfer analysis, we show that the impact of vdW corrections on the charge distribution leads to a subtle strengthening of hydrogen bonds between chiral cations and inorganic octahedra, resulting in an increase in the binding energy. Finally, we identified that the Rashba-Dresselhaus effect in two-dimensionality is refined by vdW interactions.

Contrasting the stability, octahedral distortions, and optoelectronic properties of 3D MABX3 and 2D (BA)2(MA)B2X7 (B = Ge, Sn, Pb; X = Cl, Br, I) perovskites.

Efficient surface passivation and toxic lead (Pb) are known obstacles to the photovoltaic application of perovskite-based solar cells. A possible solution for these problems is to use thin-films of two-dimensional (2D) perovskite-based materials and the replacement of Pb with alternative divalent cations (B); however, our atomistic understanding of the differences between (3D) three-dimensional and 2D perovskite-based materials is far from satisfactory. Herein, we report a systematic theoretical investigation based on ab initio density functional theory (DFT) calculations for both 3D MABX3 and the Ruddlesden-Popper 2D (BA)2(MA)B2X7 (B = Ge, Sn, Pb, and X = Cl, Br, I) compounds to investigate the differences (contrasts) in selected physical-chemical properties, i.e., structural parameters, energetic stability, electronic, and optical properties. We found an increased cation/anion charge separation because of the presence of organic spacers, which results in stronger Coulomb interactions in the inorganic framework, and hence, it enhances the cohesive energy (stability) within the inorganic layer. The inorganic layer constitutes the optically active region that contributes to the superior performance of perovskite-based solar cells. We quantified this effect by comparing the average electronic charges at the X sites in both 2D and 3D perovskites. This comparison is then correlated with variations in BX6-octahedron volumes, resulting in a monotonic relation. Moreover, the electronic structure characterization demonstrates that Ge-based systems present weakly sensitive band gaps to dimensionality due to a compensatory effect between Jahn-Teller distortions and quantum confinement. Lead-free GeI-, SnBr-, and SnI-based perovskites have DFT band gaps closer to the optimal value used in photovoltaic applications. Finally, as expected, the 2D systems absorption coefficients show pronounced anisotropy.

Navigating the Blood-Brain Barrier: Challenges and Therapeutic Strategies in Breast Cancer Brain Metastases.

Breast cancer (BC) is the most common cancer in women, with metastatic BC being responsible for the highest number of deaths. A frequent site for BC metastasis is the brain. Brain metastasis derived from BC involves the cooperation of multiple genetic, epigenetic, angiogenic, and tumor-stroma interactions. Most of these interactions provide a unique opportunity for development of new therapeutic targets. Potentially targetable signaling pathways are Notch, Wnt, and the epidermal growth factor receptors signaling pathways, all of which are linked to driving BC brain metastasis (BCBM). However, a major challenge in treating brain metastasis remains the blood-brain barrier (BBB). This barrier restricts the access of unwanted molecules, cells, and targeted therapies to the brain parenchyma. Moreover, current therapies to treat brain metastases, such as stereotactic radiosurgery and whole-brain radiotherapy, have limited efficacy. Promising new drugs like phosphatase and kinase modulators, as well as BBB disruptors and immunotherapeutic strategies, have shown the potential to ease the disease in preclinical studies, but remain limited by multiple resistance mechanisms. This review summarizes some of the current understanding of the mechanisms involved in BC brain metastasis and highlights current challenges as well as opportunities in strategic designs of potentially successful future therapies.

Dopamine D1 receptor activation drives plasticity in the songbird auditory pallium.

Vocal learning species must form and extensively hone associations between sounds and social contingencies. In songbirds, dopamine signaling guides song motor-production, variability, and motivation, but it is unclear how dopamine regulates fundamental auditory associations for learning new sounds. We hypothesized that dopamine regulates learning in the auditory pallium, in part by interacting with local neuroestradiol signaling. Here, we show that zebra finch auditory neurons frequently coexpress D1 receptor (D1R) protein, neuroestradiol-synthase, GABA, and parvalbumin. Auditory classical conditioning increased neuroplasticity gene induction in D1R-positive neurons. In vitro, D1R pharmacological activation reduced the amplitude of GABAergic and glutamatergic currents and increased the latter's frequency. In vivo, D1R activation reduced the firing of putative interneurons, increased the firing of putative excitatory neurons, and made both neuronal types unable to adapt to novel stimuli. Together, these findings support the hypothesis that dopamine acting via D1Rs modulates auditory association in the songbird sensory pallium.SIGNIFICANCE STATEMENTOur key finding is that auditory forebrain D1 receptors modulate auditory plasticity, in support of the hypothesis that dopamine modulates the formation of associations between sounds and outcomes. Recent work in songbirds has identified roles for dopamine in driving reinforcement learning and motor variability in song production. This leaves open whether dopamine shapes the initial events that are critical for learning vocalizations, e.g., auditory learning. Our study begins to address this question in the songbird caudomedial nidopallium (NCM), an analogue of the mammalian secondary auditory cortex. Our findings indicate that dopamine receptors are important modulators of excitatory/inhibitory balance and sound association learning mechanisms in the NCM, a system that could be a fundamental feature of vertebrate ascending auditory pathways.

Single nCounter assay for prediction of MYCN amplification and molecular classification of medulloblastomas: a multicentric study.

PURPOSE: Medulloblastoma is the most frequent pediatric malignant brain tumor, and is divided into four main subgroups: WNT, SHH, group 3, and group 4. MYCN amplification is an important medulloblastoma prognostic biomarker. We aimed to molecular classify and predict MYCN amplification in a single assay. METHODS: It was included 209 medulloblastomas from 205 patients (Brazil, Argentina, and Portugal), divided into training (n = 50) and validation (n = 159) sets. A nCounter assay was carried out using a custom panel for molecular classification, with additional genes, including MYCN. nSolver 4.0 software and the R environment were used for profiling and MYCN mRNA analysis. MYCN amplification by FISH was performed in 64 cases. RESULTS: The 205 medulloblastomas were classified in SHH (44.9%), WNT (15.6%), group 3 (18.1%) and group 4 (21.4%). In the training set, MYCN amplification was detected in three SHH medulloblastomas by FISH, which showed significantly higher MYCN mRNA counts than non-FISH amplified cases, and a cutoff for MYCN amplification was established ([Formula: see text] + 4σ = 11,124.3). Applying this threshold value in the validation set, we identified MYCN mRNA counts above the cutoff in three cases, which were FISH validated. CONCLUSION: We successfully stratified medulloblastoma molecular subgroups and predicted MYCN amplification using a single nCounter assay without the requirement of additional biological tissue, costs, or bench time.

Antiviral fungal metabolites and some insights into their contribution to the current COVID-19 pandemic.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak, which started in late 2019, drove the scientific community to conduct innovative research to contain the spread of the pandemic and to care for those already affected. Since then, the search for new drugs that are effective against the virus has been strengthened. Featuring a relatively low cost of production under well-defined methods of cultivation, fungi have been providing a diversity of antiviral metabolites with unprecedented chemical structures. In this review, we present viral RNA infections highlighting SARS-CoV-2 morphogenesis and the infectious cycle, the targets of known antiviral drugs, and current developments in this area such as drug repurposing. We also explored the metabolic adaptability of fungi during fermentation to produce metabolites active against RNA viruses, along with their chemical structures, and mechanisms of action. Finally, the state of the art of research on SARS-CoV-2 inhibitors of fungal origin is reported, highlighting the metabolites selected by docking studies.

Effects of stanniocalcin hormones on rat hepatic glucose homeostasis under fed and fasted conditions.

To test the hypothesis of conservation of stanniocalcin 1 and 2 (STC-1; STC-2) metabolic functions in vertebrates, we performed an in vitro study to determine if these hormones are implicated in regulation of the gluconeogenesis pathway, glycogen synthesis, and 14C-glucose conversion to 14CO2 in livers from fed and fasting rats (Rattus norvegicus). Stc1 and Stc2 gene expressions increased in the liver after fasting. STC-1 participated in the regulation of the hepatic gluconeogenesis pathway in rats when the precursor was 14C-lactate. STC-2 demonstrated variational signaling on rat hepatic gluconeogenesis activity and Pck1 gene expression, decreasing levels in the fed state when the substrate was 14C-alanine and increasing levels during fasting when the substrate was 14C-lactate. At the concentrations used in this study, STC-1 and STC-2 did not affect glycogen concentration and synthesis from 14C-glucose or 14C-glucose conversion to 14CO2 in the livers from fed or fasting rats. These findings highlight the role of stanniocalcins in the hepatic gluconeogenesis pathway in mammals and confirm the conservation of STC-1 and STC-2 metabolic functions in the vertebrates.

Auditory learning in an operant task with social reinforcement is dependent on neuroestrogen synthesis in the male songbird auditory cortex.

Animals continually assess their environment for cues associated with threats, competitors, allies, mates or prey, and experience is crucial for those associations. The auditory cortex is important for these computations to enable valence assignment and associative learning. The caudomedial nidopallium (NCM) is part of the songbird auditory association cortex and it is implicated in juvenile song learning, song memorization, and song perception. Like human auditory cortex, NCM is a site of action of estradiol (E2) and is enriched with the enzyme aromatase (E2-synthase). However, it is unclear how E2 modulates auditory learning and perception in the vertebrate auditory cortex. In this study we employ a novel, auditory-dependent operant task governed by social reinforcement to test the hypothesis that neuro-E2 synthesis supports auditory learning in adult male zebra finches. We show that local suppression of aromatase activity in NCM disrupts auditory association learning. By contrast, post-learning performance is unaffected by either NCM aromatase blockade or NCM pharmacological inactivation, suggesting that NCM E2 production and even NCM itself are not required for post-learning auditory discrimination or memory retrieval. Therefore, neuroestrogen synthesis in auditory cortex supports the association between sounds and behaviorally relevant consequences.

Monitoring Plant Status and Fertilization Strategy through Multispectral Images.

A crop monitoring system was developed for the supervision of organic fertilization status on tomato plants at early stages. An automatic and nondestructive approach was used to analyze tomato plants with different levels of water-soluble organic fertilizer (3 + 5 NK) and vermicompost. The evaluation system was composed by a multispectral camera with five lenses: green (550 nm), red (660 nm), red edge (735 nm), near infrared (790 nm), RGB, and a computational image processing system. The water-soluble fertilizer was applied weekly in four different treatments: (T0: 0 mL, T1: 6.25 mL, T2: 12.5 mL and T3: 25 mL) and the vermicomposting was added in Weeks 1 and 5. The trial was conducted in a greenhouse and 192 images were taken with each lens. A plant segmentation algorithm was developed and several vegetation indices were calculated. On top of calculating indices, multiple morphological features were obtained through image processing techniques. The morphological features were revealed to be more feasible to distinguish between the control and the organic fertilized plants than the vegetation indices. The system was developed in order to be assembled in a precision organic fertilization robotic platform.

Unraveling chloroplast transcriptomes with ChloroSeq, an organelle RNA-Seq bioinformatics pipeline.

Online sequence repositories are teeming with RNA sequencing (RNA-Seq) data from a wide range of eukaryotes. Although most of these data sets contain large numbers of organelle-derived reads, researchers tend to ignore these data, focusing instead on the nuclear-derived transcripts. Consequently, GenBank contains massive amounts of organelle RNA-Seq data that are just waiting to be downloaded and analyzed. Recently, a team of scientists designed an open-source bioinformatics program called ChloroSeq, which systemically analyzes an organelle transcriptome using RNA-Seq. The ChloroSeq pipeline uses RNA-Seq alignment data to deliver detailed analyses of organelle transcriptomes, which can be fed into statistical software for further analysis and for generating graphical representations of the data. In addition to providing data on expression levels via coverage statistics, ChloroSeq can examine splicing efficiency and RNA editing profiles. Ultimately, ChloroSeq provides a well-needed avenue for researchers of all stripes to start exploring organelle transcription and could be a key step toward a more thorough understanding of organelle gene expression.

The role played by the molecular geometry on the electronic transport through nanometric organic films.

The electronic transport properties in molecular heterojunctions are intimately connected with the molecular conformation between the electrodes, and the electronic structure of the molecule/electrode interface. In this work, we perform an ab initio density-functional-theory investigation of the structural and transport properties through self-assembled CuPc molecules sandwiched between gold contacts with (111) surfaces. We demonstrated (i) a tunneling regime ruled by the π orbitals of the aromatic rings of CuPc molecules; and (ii) a high variation (up to two orders of magnitude) of the current density with the orientation of the CuPc molecules relative to the gold surface. The source of this variation is the geometrical dependence of the energy of the highest-occupied-molecular-orbital with respect to the chemical potential of the metal and the generation of intra-molecular transport channels for a configuration with CuPc molecules tilted with respect to the gold surface.

Electronic transport properties of MoS2 nanoribbons embedded in butadiene solvent.

Transition metal dichalcogenides (TMDCs) are promising materials for applications in nanoelectronics and correlated fields, where their metallic edge states play a fundamental role in the electronic transport. In this work, we investigate the transport properties of MoS2 zigzag nanoribbons under a butadiene (C4H6) atmosphere, as this compound has been used to obtain MoS2 flakes by exfoliation. We use density functional theory combined with non-equilibrium Green's function techniques, in a methodology contemplating disorder and different coverages. Our results indicate a strong modulation of the TMDC electronic transport properties driven by butadiene molecules anchored at their edges, producing the suppression of currents due to a backscattering process. Our results indicate a high sensitivity of the TMDC edge states. Thus, the mechanisms used to reduce the dimensionality of MoS2 considerably modify its transport properties.

Edge, size, and shape effects on WS2, WSe2, and WTe2 nanoflake stability: design principles from an ab initio investigation.

An improved atomistic understanding of the W-based two-dimensional transition-metal dichalcogenides (2D TMDs) is crucial for technological applications of 2D materials, since the presence of tungsten endows these materials with distinctive properties. However, our atomistic knowledge on the evolution of the structural, electronic, and energetic properties and on the nanoflake stability of such materials is not properly addressed hitherto. Thus, we present a density functional theory (DFT) study of stoichiometric (WQ2)n nanoflakes, with Q = S, Se, Te, and n = 1,…,16, 36, 66, and 105. We obtained the configurations with n = 1,…,16 through the tree growth algorithm whereas the nanoflakes with n = 36, 66, and 105 were generated from fragments of 2D TMDs with an abundant diversity of shapes and edge configurations. We found that all the most stable nanoflakes present the same Q-terminated edge configuration. Furthermore, in isomers with n = 1,…,16 sizes, nanoflakes with triangular shapes and their derivatives, such as the rhombus geometry, define magic numbers, whereas for n > 16, triangular shapes were also found for the most stable structures, because they preserve the edge configuration. A strong modulation of the Hirshfeld charges, depending on chalcogen species and core or edge position, is also observed. The modulation of the Hirshfeld charge due to the nature of the W metal atoms makes the energetic 1D → 1T' transition of (WQ2)n differ in nanoflake size in relation to (MoQ2)n nanoflakes. Our analysis shows the interplay between edge configuration, coordination environment, and shape that determines the stability of nanoflakes, and allows us to describe design principles for stable 1T' stoichiometric nanoflakes of various sizes.

Supplementation of L-glycine and L-glutamate to Japanese quails from 01 to 36 days of age using the ideal protein concept.

Experiment I: T1-1 =  basal diet with 25% crude protein (CP) + limiting amino acids (LA); T1-2  = 20% CP + LA; T1-3  = 20% CP + LA + L-glycine; T1-4  = 20% CP + LA + L-glutamate; T1-5  = 20% CP + LA + L-glycine + L-glutamate. Experiment II: T2-1  = basal diet with 22% CP + LA; T2-2  = 20% CP + LA; T2-3  = 17.6% CP + LA + L-glycine; T2-4  = 17.6% CP + LA + L-glutamate; T2-5  = 17.6% CP + LA + L-glycine + L-glutamate. The reduction of dietary protein based on the concept of ideal protein decreases nitrogen excretion in quails when L-glycine is added to the diets. Quails fed diets supplemented with L-glutamate as the non-specific nitrogen source equivalent to the nitrogen level of the control diet had increased nitrogen excretion. However, quails had reduced nitrogen excretion in both experiments when L-glycine was added to diets with L-glutamate. Carcass fat was increased by reducing dietary protein, but fat deposition was reduced by adding L-glutamate and L-glycine, or both. The dietary addition of L-glutamate and L-glycine in quails based on the ideal protein concept is not necessary (Exp. I). Although the total nitrogen, electrolytic balance and glycine level were adjusted in diets, quails had decreased performance. Therefore, other hypotheses besides protein reduction need to be studied (Exp. II). Protein reduction with supplementation of only limiting essential amino acids does not affect quail performance. Dietary addition of L-glycine reduces nitrogen excretion.

Norepinephrine enhances song responsiveness and encoding in the auditory forebrain of male zebra finches.

Norepinephrine (NE) can dynamically modulate excitability and functional connectivity of neural circuits in response to changes in external and internal states. Regulation by NE has been demonstrated extensively in mammalian sensory cortices, but whether NE-dependent modulation in sensory cortex alters response properties in downstream sensorimotor regions is less clear. Here we examine this question in male zebra finches, a songbird species with complex vocalizations and a well-defined neural network for auditory processing of those vocalizations. We test the hypothesis that NE modulates auditory processing and encoding, using paired extracellular electrophysiology recordings and pattern classifier analyses. We report that a NE infusion into the auditory cortical region NCM (caudomedial nidopallium; analogous to mammalian secondary auditory cortex) enhances the auditory responses, burst firing, and coding properties of single NCM neurons. Furthermore, we report that NE-dependent changes in NCM coding properties, but not auditory response strength, are transmitted downstream to the sensorimotor nucleus HVC. Finally, NE modulation in the NCM of males is qualitatively similar to that observed in females: in both sexes, NE increases auditory response strengths. However, we observed a sex difference in the mechanism of enhancement: whereas NE increases response strength in females by decreasing baseline firing rates, NE increases response strength in males by increasing auditory-evoked activity. Therefore, NE signaling exhibits a compensatory sex difference to achieve a similar, state-dependent enhancement in signal-to-noise ratio and coding accuracy in males and females. In summary, our results provide further evidence for adrenergic regulation of sensory processing and modulation of auditory/sensorimotor functional connectivity. NEW & NOTEWORTHY This study documents that the catecholamine norepinephrine (also known as noradrenaline) acts in the auditory cortex to shape local processing of complex sound stimuli. Moreover, it also enhances the coding accuracy of neurons in the auditory cortex as well as in the downstream sensorimotor cortex. Finally, this study shows that while the sensory-enhancing effects of norepinephrine are similar in males and females, there are sex differences in the mode of action.

Double-walled silicon nanotubes: an ab initio investigation.

The synthesis of silicon nanotubes realized in the last decade demonstrates multi-walled tubular structures consisting of Si atoms in [Formula: see text] and the [Formula: see text] hybridizations. However, most of the theoretical models were elaborated taking as the starting point [Formula: see text] structures analogous to carbon nanotubes. These structures are unfavorable due to the natural tendency of the Si atoms to undergo [Formula: see text]. In this work, through ab initio simulations based on density functional theory, we investigated double-walled silicon nanotubes proposing layered tubes possessing most of the Si atoms in an [Formula: see text] hybridization, and with few [Formula: see text] atoms localized at the outer wall. The lowest-energy structures have metallic behavior. Furthermore, the possibility to tune the band structure with the application of a strain was demonstrated, inducing a metal-semiconductor transition. Thus, the behavior of silicon nanotubes differs significantly from carbon nanotubes, and the main source of the differences is the distortions in the lattice associated with the tendency of Si to make four chemical bonds.

Adult Neurogenesis Leads to the Functional Reconstruction of a Telencephalic Neural Circuit.

UNLABELLED: Seasonally breeding songbirds exhibit pronounced annual changes in song behavior, and in the morphology and physiology of the telencephalic neural circuit underlying production of learned song. Each breeding season, new adult-born neurons are added to the pallial nucleus HVC in response to seasonal changes in steroid hormone levels, and send long axonal projections to their target nucleus, the robust nucleus of the arcopallium (RA). We investigated the role that adult neurogenesis plays in the seasonal reconstruction of this circuit. We labeled newborn HVC neurons with BrdU, and RA-projecting HVC neurons (HVCRA) with retrograde tracer injected in RA of adult male white-crowned sparrows (Zonotrichia leucophrys gambelii) in breeding or nonbreeding conditions. We found that there were many more HVCRA neurons in breeding than nonbreeding birds. Furthermore, we observed that more newborn HVC neurons were back-filled by the tracer in breeding animals. Behaviorally, song structure degraded as the HVC-RA circuit degenerated, and recovered as the circuit regenerated, in close correlation with the number of new HVCRA neurons. These results support the hypothesis that the HVC-RA circuit degenerates in nonbreeding birds, and that newborn neurons reconstruct the circuit in breeding birds, leading to functional recovery of song behavior. SIGNIFICANCE STATEMENT: We investigated the role that adult neurogenesis plays in the seasonal reconstruction of a telencephalic neural circuit that controls song behavior in white-crowned sparrows. We showed that nonbreeding birds had a 36%-49% reduction in the number of projection neurons compared with breeding birds, and the regeneration of the circuit in the breeding season is due to the integration of adult-born projection neurons. Additionally, song structure degraded as the circuit degenerated and recovered as the circuit regenerated, in close correlation with new projection neuron number. This study demonstrates that steroid hormones can help reestablish functional neuronal circuits following degeneration in the adult brain and shows non-injury-induced degeneration and reconstruction of a neural circuit critical for producing a learned behavior.

Characterization of NADPH Diaphorase- and Doublecortin-Positive Neurons in the Lizard Hippocampal Formation.

The lizard cortex has remarkable similarities with the mammalian hippocampus. Both regions process memories, have similar cytoarchitectural properties, and are important neurogenic foci in adults. Lizards show striking levels of widespread neurogenesis in adulthood and can regenerate entire cortical areas after injury. Nitric oxide (NO) is an important regulatory factor of mammalian neurogenesis and hippocampal function. However, little is known about its role in nonmammalian neurogenesis. Here, we analyzed the distribution, morphology, and dendritic complexity (Neurolucida reconstructions) of NO-producing neurons through NADPH diaphorase (NADPHd) activity, and how they compare with the distribution of doublecortin-positive (DCX+) neurons in the hippocampal formation of the neotropical lizard Tropidurus hispidus. NADPHd-positive (NADPHd+) neurons in the dorsomedial cortex (DMC; putatively homologous to mammalian CA3) were more numerous and complex than the ones in the medial cortex (MC; putatively homologous to the dentate gyrus). We found that NADPHd+ DMC neurons send long projections into the MC. Interestingly, in the MC, NADPHd+ neurons existed in 2 patterns: small somata with low intensity of staining in the outer layer and large somata with high intensity of staining in the deep layer, a pattern similar to the mammalian cortex. Additionally, NADPHd+ neurons were absent in the granular cell layer of the MC. In contrast, DCX+ neurons were scarce in the DMC but highly numerous in the MC, particularly in the granular cell layer. We hypothesize that NO-producing neurons in the DMC provide important input to proliferating/migrating neurons in the highly neurogenic MC.

Pervasive transcription of plant organelle genomes: functional noncoding transcriptomes?

Plant mitochondrial and plastid genomes typically show pervasive, genome-wide transcription. Little is known, however, about the utility of organelle noncoding RNAs, which often make up most of the transcriptome. Here, we suggest that long-read sequencing data combined with dedicated RNA databases could help identify putative functional organelle noncoding transcripts.