The SEA-PHAGES program maintains an extensive archive of student-discovered Actinobacteriophage as a resource for understanding phage diversity. Here, we examine host range of thirty phages isolated on Arthrobacter globiformis B-2979 against additional strains of A. globiformis and against other isolates within ' Arthrobacter sensu stricto '. Consistent with other reports, host range of these phages was generally narrow. A general relationship between magnitude and prevalence was observed in efficiency of plating on globiformis isolates other than the isolation host, suggesting underlying mechanisms of cross-infectivity.
In C. elegans , gap junctions between command interneurons and motor neurons mediate rapid behavioural transitions. However, antidromic backpropagation driven by the putative proprioceptive activity of motor neurons with Extended Longitudinal Neurites (ELNs) must be blocked to maintain circuit directionality. Analysing single-cell transcriptomics (CeNGEN), I identify systematic innexin gene expression asymmetry across major motor circuit electrical synapses. Presynaptic interneurons and postsynaptic motor neurons express distinct, non-overlapping innexin subunits. This molecular asymmetry suggests a rectified, diode-like gating mechanism that favours orthodromic signalling while preventing antidromic backpropagation from proprioceptive motor neurons, providing a structural framework for directional electrical transmission.
The Caenorhabditis Intervention Testing Program recently characterized the longevity-promoting effects of all-trans-retinoic acid (atRA) in C. elegans . While we observed that atRA extended lifespan across multiple genetic backgrounds, environmental factors may influence its efficacy. One such factor is 5-Fluoro-2'-deoxyuridine (FUdR), used to prevent progeny contamination in lifespan assays. Here, we show that FUdR enhances atRA's lifespan effects, but that this potentiation is not simply due to progeny elimination, as sterilization through auxin-mediated disruption of spermatogenesis does not potentiate atRA in lifespan extension. We conclude that atRA longevity is dependent on additional effects of FUdR that remain uncharacterized.
Tau aggregation is a hallmark of neurodegenerative diseases including Alzheimer's disease and frontotemporal dementia. Here, we tested how an obesogenic diet affects a Drosophila tauopathy model across multiple behavioral assays. In group-housed flies, mutant tau shortened lifespan, and this effect was worsened by a high-sugar diet. We also examined sleep, motor behavior, and sensory responsiveness. Tau-expressing flies differed from controls in all assays, but these deficits were not further exacerbated by diet. These findings reveal assay-specific diet effects and highlight the value of using multiple behavioral measures to characterize tau mutant phenotypes.
Sensory systems are energetically expensive and may evolve through tradeoffs between modalities. We tested the sensory tradeoff hypothesis in four hover fly species by examining allometry and sexual dimorphism in eye and antennal (funiculus) size. Across species, larger flies exhibited larger sensory structures and males generally possessed relatively larger eyes and funiculi than females after controlling for body size. However, we found no consistent negative relationship between eye and antennal investment within species. These findings suggest that sensory investment in hover flies is shaped more strongly by allometric and sex-specific selection pressures than by compensatory tradeoffs between sensory modalities.
Leishmaniasis is a parasitic disease for which existing treatments can be toxic and costly, and resistance to current therapies is becoming increasingly common. This study implemented a systematic review of data regarding antileishmanial activity in plant-derived compounds and used machine learning techniques to train and test a Random Forest algorithm to predict the antileishmanial activity of plant-derived compounds. Asteraceae, Euphorbiaceae, Lamiaceae, and Myrtaceae plant families were identified for their high or moderate antileishmanial activity and nativity to areas of high leishmaniasis prevalence. The Random Forest model had 89% prediction accuracy, with an out-of-bag error rate of 16%.
Aging increases the prevalence of diseases with mitochondrial dysfunction, notably Alzheimer's and Parkinson's. This study assesses MitoTimer-based mitochondrial dynamics across the lifespan between neurons and glia. MitoTimer was expressed in neurons using nSyb-Gal4 and in glia using Repo-Gal4. MitoTimer red:green fluorescence ratios were quantified within or surrounding the mushroom body calyx of young, middle-aged, and old female Drosophila melanogaster . Paraquat-supplemented food increased red:green ratios relative to controls, supporting our use of MitoTimer. Neuronal red:green ratios peaked in middle age, whereas glial ratios were highest in young flies. These findings reveal distinct, age-dependent mitochondrial dynamics in neurons and glia.
Stem cell proliferation rates must be precisely regulated as insufficient proliferation leads to tissue loss, whereas excessive proliferation causes tumorigenesis and cancer. A homeostatic balance is therefore achieved through feedback loops that adjust stem/progenitor cell proliferation rates to match the demand for their differentiated progeny. While such a homeostatic feedback mechanism adjusts germline stem cell (GSC) proliferation rates to oocyte needs in the Caenorhabditis elegans adult hermaphrodite germline, its inner workings are incompletely understood. Here we show that the Gα GOA-1 /GNAO1 is required specifically in the gonadal sheath cells to non-autonomously promote GSC quiescence in spermless hermaphrodites. Given that dysregulation of G protein signalling is frequently observed in human cancers, Gα dependent homeostatic control of stem cell proliferation may represent a conserved tumour suppressive mechanism.
The eIF4ET family protein IFET-1 is needed for oocyte development and long-term storage in C. elegans . How IFET-1 plays multiple roles in oocyte biology is unclear. Using pull-downs and mass spectrometry, we identified proteins that interact with IFET-1 . We show that three IFET-1-interacting partners- PENR-1 , SQD-1 , and LSM-4 -are essential for producing viable oocytes in C. elegans females.
Frontotemporal Dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS) overlap considerably in genetic origin and pathology. Multiple C. elegans models of ALS/FTD have been developed, but the integrity of glutamatergic neurons in these models has not been thoroughly evaluated. Here, we report degeneration of glutamatergic phasmid neurons in animals expressing either wild-type or disease variant V337M human tau, and mild degeneration in animals expressing disease variant M337V human TDP-43. Defects caused by ectopic expression of tau were suppressed by loss of the known modifier, spop-1 , suggesting that SPOP-1-dependent pathways are also involved in glutamatergic neuron degeneration.
Small interfering RNAs bound to Argonautes ALG-3 and ALG-4 ( ALG-3 /4) in spermatocytes regulate fertility and aging in C. elegans . ALG-3 /4 cell non-autonomously repress DAF-18 /PTEN in the oocyte, thereby limiting the activity of DAF-16 /FOXO and longevity. We find that the DAF-16 and ALG-3 /4 target gene lea-1 is downregulated in precursor germ cells and oocytes of alg-3 /4 mutants while being upregulated in age-1 ( hx546 ) PI3K mutants, where DAF-16 is activated. The downregulation of lea-1 in alg-3 /4 mutants is inherited, unlike the elevation in DAF-18 levels. We therefore propose that ALG-3 /4 regulate LEA-1 and DAF-18 through distinct non-autonomous mechanisms.
Infertility impacts one in seven couples globally, with one-third of cases classified as unexplained. One source of unexplained infertility is the spermatozoon centrosome, a subcellular structure composed of two remodeled centrioles (the proximal and distal centrioles) and specialized pericentriolar material, located in the spermatozoon neck. The centrosome functions as the head-neck linker in the spermatozoa. Here, we investigated the localization of the somatic cell centriole lumen protein POC1A using immunofluorescence and confocal microscopy. We found that POC1A localizes to the neck, colocalizing with POC1B, and is present in both the proximal and distal centrioles in both human and bovine spermatozoa.
The Muwekma Ohlone Tribe of the San Francisco Bay Area conducted a cultural burn in oak woodland as part of cultural revitalization efforts. This low-intensity burn only moderately affected soil nematodes that infest acorn-feeding insects. The nematodes were frequently found after the burn, even within burned piles. This finding suggests that cultural burning may help to prevent outbreaks of acorn-feeding insects not only directly by killing them with heat, but also indirectly by having only minor effects on the soil nematodes. Preventing outbreaks of acorn-feeding insects increases the likelihood of more acorns being available for wildlife and cultural use.
The Arc gene is rapidly expressed in the dentate gyrus of the hippocampus during learning and is essential for long-term memory formation. Although memory consolidation, which occurs predominantly during sleep, depends on Arc, previous studies have reported conflicting findings regarding whether Arc expression changes across the sleep-wake cycle. As an initial step toward addressing these discrepancies, we established a baseline comparison of Arc expression in the dentate gyrus of naïve Fischer (CDF) rats (n = 44) across four timepoints spanning sleep and wake periods. Arc⁺ cell density remained remarkably stable across all timepoints.
Adult stem cells are required to maintain tissue homeostasis and understanding their regulation is essential to leveraging their utility. Here we report that seven transgenic ionotropic glutamate receptor (iGluR) subunit reporter lines are variably expressed in hub cells of the Drosophila testis stem cell niche, suggesting a novel form of inter-organ communication for this tissue. While HCR-FISH confirms that one of the iGluR subunits, GluRIIA , is transcribed in hub cells, we do not detect GluRIIA protein expression. Furthermore, hub cells are not sensitive to exogenous glutamate and hub-specific knockdown of the essential iGluR subunits does not phenotypically affect cells of the testis apex. Altogether this suggests that iGluRs are not essential for stem cell niche homeostasis.
Biotin deficiency impairs lipid accumulation in 3T3-F442A adipocytes despite allowing adipocyte differentiation. Here, we examined whether transglutaminase, a cytoskeletal remodeling enzyme associated with lipid droplets, is affected by biotin availability. Under biotin-deficient conditions, adipocytes showed reduced lipid droplet formation, cytoplasmic empty vesicle-like structures, and decreased transglutaminase expression and activity. Pharmacological inhibition of transglutaminase reduced lipid accumulation and decreased malic enzyme activity, suggesting a link between transglutaminase activity and NADPH-dependent lipogenesis. These findings identify transglutaminase as a biotin-sensitive component associated with lipid accumulation in 3T3-F442A adipocytes.
We developed a gene model for the GST-containing FLYWCH zinc-finger protein ortholog ( gfzf ) in the ASM1890373v1 Genome Assembly (GenBank Accession: GCA_018903735.1 ) of Drosophila cardini . This ortholog was characterized as part of a developing dataset for a comparative study of detoxification gene family evolution in the immigrans - tripunctata radiation of the genus Drosophila using an adapted Genomics Education Partnership gene annotation protocol for Course-based Undergraduate Research Experiences.
STAT3 phosphorylation and transcriptional activity promote breast cancer growth and metastasis. We have previously reported that the transcriptional adaptor LMO2 is required for metastasis in breast cancer and promotes STAT3-JAK2 interaction, leading to STAT3 phosphorylation in metastasis-initiating cells. Here, we find that constitutively activated STAT3 is insufficient to drive metastasis in the absence of LMO2. Mechanistically, we find that LMO2 is required not only for STAT3 phosphorylation in the cytoplasm but also for STAT3 translocation to the nucleus. These data suggest that LMO2 promotes STAT3 activation and localization to the nucleus in breast cancer cells.
Gene model for the ortholog of Protein tyrosine phosphatase 61F ( Ptp61F ) in the Drosophila ananassae May 2011 (Agencourt dana_caf1/DanaCAF1) Genome Assembly (GenBank Accession: GCA_000005115.1). This ortholog was characterized as part of a developing dataset to study the evolution of the Insulin/insulin-like growth factor signaling pathway (IIS) across the genus Drosophila using the Genomics Education Partnership gene annotation protocol for Course-based Undergraduate Research Experiences.
We developed a gene model for the CG31087 ortholog in the ASM1815116v1 Genome Assembly (GenBank Accession: GCA_018151165.1 ) of Drosophila arawakana . This ortholog was characterized as part of a developing dataset for a comparative study of detoxification gene family evolution in the immigrans - tripunctata radiation of the genus Drosophila using an adapted Genomics Education Partnership gene annotation protocol for Course-based Undergraduate Research Experiences.
