Presynaptic Translation: Stepping Out of the Postsynaptic Shadow

The ability of the nervous system to convert transient experiences into long-lasting structural changes at the synapse relies upon protein synthesis. It has become increasingly clear that a critical subset of this synthesis occurs within the synaptic compartment. While this process has been extensively characterized in the postsynaptic compartment, the contribution of local translation to presynaptic function remains largely unexplored. However, recent evidence highlights the potential importance of translation within the presynaptic compartment. Work in cultured neurons has shown that presynaptic translation occurs specifically at synapses undergoing long-term plasticity and may contribute to the maintenance of nascent synapses. Studies from our laboratory have demonstrated that Fragile X proteins, which regulate mRNA localization and translation, are expressed at the presynaptic apparatus. Further, mRNAs encoding presynaptic proteins traffic into axons. Here we discuss recent advances in the study of presynaptic translation as well as the challenges confronting the field. Understanding the regulation of presynaptic function by local protein synthesis promises to shed new light on activity-dependent modification of synaptic architecture

Spring Triticale Forage Yield and Nutritive Value as Affected by Location and Maturity in Wisconsin

Spring triticale (X Triticosecale Wittm.) has a nutritional value that is like other spring cereal grain forages and presents a wide range in value and potential for ruminant feed (Emile et al. 2007). As varieties are improved, they may compete with oats as a spring forage source. A multi-location evaluation was conducted during 2021 in Wisconsin (Spooner, Marshfield and Lancaster) to evaluate spring triticale varieties harvested at two maturities (boot and mature stage) for yield and nutritive value. Treatments included six spring triticale varieties (AR-1, AR-2, AR-3, AR-4 and a local oat (WI-O) and triticale (WI-T) variety. Response variables measured included DM yield, and nutritive value constituents [crude protein (CP), digestibility (IVDMD, NDFD), carbohydrates (WSC, fructans, starch), fiber components (NDF, ADF, lignin) and minerals (P, K, Ca)]. Yield and nutritive value variables had interactions with locations (P \u3c 0.01). Yield for all treatments were higher at mid and south locations compared to the northern Spooner location (P \u3c 0.01). This work presents baseline information and discusses the trade off between yield and quality at the northern-most location with lower precipitation and growing degree days (GDD), leading to lower yield but higher nutritive value, as compared to mid and southern-most locations. The increasing extremes observed in weather patterns, in terms of precipitation and temperature, warrants future evaluations

Autoradiographic Localization of [3H]-Nisoxetine Binding Sites in the CNS of Male and Female Japanese Quail

Background In the central nervous system of mammals, transporters localized on the presynaptic nerve terminals regulate the reuptake of neurotransmitters. These transporters are selective for a specific neurotransmitter such as dopamine (DA) and norepinephrine (NE). Specifically in the synapse, the dopamine transporter (DAT) reuptakes DA and the norepinephrine transporter (NET) reuptakes NE. However previous research has found that avian species do not have a gene for DAT, and therefore, birds may be using the NET to clear both NE and DA from the synapse. The current study aimed to extend this finding by localizing NET expression in male and female Japanese quail (Coturnix japonica) brains using [3H]Nisoxetine, a selective NET blocker. Results High densities of binding sites were observed in the olfactory tubercle (OTu), the medial striatum (MSt), and the lateral striatum (LSt). Lower densities of binding sites were detected in the amygdala (AMY) and hypothalamus (Hyp), and low binding was found in the medial preoptic area (mPOA) and the pallium. Conclusion The areas with the highest densities of NET are also areas that previous research has shown to have high levels of DA activity but low levels of NE innervation (e.g. striatum). The distribution of this reuptake transporter is consistent with the theory that NET acts to clear both DA and NE from the synapse

EGFP insertional mutagenesis reveals multiple FXR2P fibrillar states with differing ribosome association in neurons

RNA-binding proteins (RBPs) function in higher-order assemblages such as RNA granules to regulate RNA localization and translation. The Fragile X homolog FXR2P is an RBP essential for formation of neuronal Fragile X granules that associate with axonal mRNA and ribosomes in the intact brain. However, the FXR2P domains important for assemblage formation in a cellular system are unknown. Here we used an EGFP insertional mutagenesis approach to probe for FXR2P intrinsic features that influence its structural states. We tested 18 different in-frame FXR2P(EGFP) fusions in neurons and found that the majority did not impact assemblage formation. However, EGFP insertion within a 23 amino acid region of the low complexity (LC) domain induced FXR2P(EGFP) assembly into two distinct fibril states that were observed in isolation or in highly-ordered bundles. FXR2P(EGFP) fibrils exhibited different developmental timelines, ultrastructures and ribosome associations. Formation of both fibril types was dependent on an intact RNA-binding domain. These results suggest that restricted regions of the LC domain, together with the RNA-binding domain, may be important for FXR2P structural state organization in neurons

Changes in Temporal and Spatial Patterns of Outer Surface Lipoprotein Expression Generate Population Heterogeneity and Antigenic Diversity in the Lyme Disease Spirochete, Borrelia burgdorferi

This is the published version. Copyright 2015 by the American Society for Microbiology.Borrelia burgdorferi differentially expresses many of the OspE/F/Elp paralogs during tick feeding. These findings, combined with the recent report that stable B. burgdorferi infection of mammals occurs only after 53 h of tick attachment, prompted us to further analyze the expression of the OspE/F/Elp paralogs during this critical period of transmission. Indirect immunofluorescence analysis revealed that OspE, p21, ElpB1, ElpB2, and OspF/BbK2.11 are expressed in the salivary glands of ticks allowed to feed on mice for 53 to 58 h. Interestingly, many of the spirochetes in the salivary glands that expressed abundant amounts of these antigens were negative for OspA and OspC. Although prior reports have indicated that OspE/F/Elp orthologs are surface exposed, none of the individual lipoproteins or combinations of the lipoproteins protected mice from challenge infections. To examine why these apparently surface-exposed lipoproteins were not protective, we analyzed their genetic stability during infection and their cellular locations after cultivation in vitro and within dialysis membrane chambers, mimicking a mammalian host-adapted state. Combined restriction fragment length polymorphism and nucleotide sequence analyses revealed that the genes encoding these lipoproteins are stable for at least 8 months postinfection. Interestingly, cellular localization experiments revealed that while all of these proteins can be surface localized, there were significant populations of spirochetes that expressed these lipoproteins only in the periplasm. Furthermore, host-specific signals were found to alter the expression patterns and final cellular location of these lipoproteins. The combined data revealed a remarkable heterogeneity in populations of B. burgdorferi during tick transmission and mammalian infection. The diversity is generated not only by temporal changes in antigen expression but also by modulation of the surface lipoproteins during infection. The ability to regulate the temporal and spatial expression patterns of lipoproteins throughout infection likely contributes to persistent infection of mammals by B. burgdorferi

Phenotype-specific association of the TGFBR3 locus with nonsyndromic cryptorchidism

PURPOSE: Based on a genome-wide association study of testicular dysgenesis syndrome showing a possible association with TGFBR3, we analyzed data from a larger, phenotypically restricted cryptorchidism population for potential replication of this signal. MATERIALS AND METHODS: We excluded samples based on strict quality control criteria, leaving 844 cases and 2,718 controls of European ancestry that were analyzed in 2 separate groups based on genotyping platform (ie Illumina® HumanHap550, version 1 or 3, or Human610-Quad, version 1 BeadChip in group 1 and Human OmniExpress 12, version 1 BeadChip platform in group 2). Analyses included genotype imputation at the TGFBR3 locus, association analysis of imputed data with correction for population substructure, subsequent meta-analysis of data for groups 1 and 2, and selective genotyping of independent cases (330) and controls (324) for replication. We also measured Tgfbr3 mRNA levels and performed TGFBR3/betaglycan immunostaining in rat fetal gubernaculum. RESULTS: We identified suggestive (p ≤ 1× 10(-4)) association of markers in/near TGFBR3, including rs9661103 (OR 1.40; 95% CI 1.20, 1.64; p = 2.71 × 10(-5)) and rs10782968 (OR 1.58; 95% CI 1.26, 1.98; p = 9.36 × 10(-5)) in groups 1 and 2, respectively. In subgroup analyses we observed strongest association of rs17576372 (OR 1.42; 95% CI 1.24, 1.60; p = 1.67 × 10(-4)) with proximal and rs11165059 (OR 1.32; 95% CI 1.15, 1.38; p = 9.42 × 10(-4)) with distal testis position, signals in strong linkage disequilibrium with rs9661103 and rs10782968, respectively. Association of the prior genome-wide association study signal (rs12082710) was marginal (OR 1.13; 95% CI 0.99, 1.28; p = 0.09 for group 1), and we were unable to replicate signals in our independent cohort. Tgfbr3/betaglycan was differentially expressed in wild-type and cryptorchid rat fetal gubernaculum. CONCLUSIONS: These data suggest complex or phenotype specific association of cryptorchidism with TGFBR3 and the gubernaculum as a potential target of TGFβ signaling

Cerebrovascular Dysfunction is Related to Depressive Symptom Severity in Young Adults

Cerebral vasodilatory responsiveness is blunted in older adults (~70 yrs) with depressive disorders and is thought to contribute to the link between depressive symptomology and increased risk for neurocognitive (e.g., dementia) and cerebral vascular (e.g., stroke) diseases. In young adults with major depressive disorder (MDD), peripheral vascular endothelial dysfunction is present and graded in relation to the severity of depressive symptoms; however, to date, limited investigations have examined cerebral vasodilatory function in young otherwise healthy adults with MDD. PURPOSE: We tested the hypothesis that cerebral vasodilatory responsiveness to a hypercapnic stimulus would be blunted in young otherwise healthy adults with MDD compared to healthy non-depressed adults (HA). Further, we hypothesized, that the magnitude of impairment in cerebrovascular function would be related to depressive symptom severity. METHODS: Ten HA (7 women; 22±2yrs) and 10 adults with MDD (8 women; 22±2yrs; n=5 tested during a major depressive episode) participated. Depressive symptom severity was evaluated with the Patient Health History Questionnaire-9 (PHQ-9) in both HA and adults with MDD. Beat-to-beat mean arterial pressure (MAP; finger photoplethysmography), middle cerebral artery blood velocity (MCAv; transcranial Doppler ultrasound), and end-tidal carbon dioxide concentration (PETCO2; capnograph) were continuously measured during baseline (i.e., normocapnia) and rebreathing-induced hypercapnia. Cerebral vascular conductance index (CVCi=MCAv•MAP-1) was calculated at baseline and at the highest common magnitude of hypercapnia achieved by all subjects during rebreathing (∆PETCO2 = 9 Torr). RESULTS: At baseline, there were no differences in MAP or CVCi between groups (both p\u3e0.05). During hypercapnia, there were no group differences in the increase in MAP (∆3±3 HA vs. ∆4±3 mmHg MDD; p=0.78). Further, neither the hypercapnia-induced increase in MCAv (∆29±7 HA vs. ∆26±8 cm•s-1 MDD; p=0.37) nor the increase in CVCi (∆39±12 HA vs. ∆30±12 %baseline MDD; p=0.13) were different between groups. However, greater severity of depressive symptoms was negatively related to cerebral vasodilatory responsiveness (R2=0.219, p=0.04). CONCLUSION: These preliminary data suggest that cerebral vasodilatory responsiveness to hypercapnia is not impaired in young adults with MDD, despite a negative relation between depressive symptom severity and the magnitude of hypercapnia-induced cerebral vasodilation

Regulation of OspE-Related, OspF-Related, and Elp Lipoproteins of Borrelia burgdorferi Strain 297 by Mammalian Host-Specific Signals

This is the published version. Copyright 2001 by the American Society for Microbiology.In previous studies we have characterized the cp32/18 loci inBorrelia burgdorferi 297 which encode OspE and OspF orthologs and a third group of lipoproteins which possess OspE/F-like leader peptides (Elps). To further these studies, we have comprehensively analyzed their patterns of expression throughout the borrelial enzootic cycle. Serial dilution reverse transcription-PCR analysis indicated that although a shift in temperature from 23 to 37°C induced transcription for all nine genes analyzed, this effect was often markedly enhanced in mammalian host-adapted organisms cultivated within dialysis membrane chambers (DMCs) implanted within the peritoneal cavities of rats. Indirect immunofluorescence assays performed on temperature-shifted, in vitro-cultivated spirochetes and organisms in the midguts of unfed and fed ticks revealed distinct expression profiles for many of the OspE-related, OspF-related, and Elp proteins. Other than BbK2.10 and ElpA1, all were expressed by temperature-shifted organisms, while only OspE, ElpB1, OspF, and BbK2.11 were expressed in the midguts of fed ticks. Additionally, although mRNA was detected for all nine lipoprotein-encoding genes, two of these proteins (BbK2.10 and ElpA1) were not expressed by spirochetes cultivated in vitro, within DMCs, or by spirochetes within tick midguts. However, the observation that B. burgdorferi-infected mice generated specific antibodies against BbK2.10 and ElpA1 indicated that these antigens are expressed only in the mammalian host and that a form of posttranscriptional regulation is involved. Analysis of the upstream regions of these genes revealed several differences between their promoter regions, the majority of which were found in the −10 and −35 hexamers and the spacer regions between them. Also, rather than undergoing simultaneous upregulation during tick feeding, these genes and the corresponding lipoproteins appear to be subject to progressive recruitment or enhancement of expression as B. burgdorferi is transmitted from its tick vector to the mammalian host. These findings underscore the potential relevance of these molecules to the pathogenic events of early Lyme disease

The Relation Between Cognitive Function and Cerebral Vasodilatory Reactivity in Young Adults with Major Depressive Disorder

Major depressive disorder (MDD) has been associated with an elevated risk of developing neurocognitive diseases (e.g., dementia). Although the precise neurobiological mechanisms remain incompletely understood, cerebrovascular dysfunction is thought to directly contribute, at least in part, to impairments in cognitive function. Cerebral vasodilatory reactivity to a hypercapnic stimulus is blunted in older adults with MDD compared to age-matched non-depressed adults. Further, impaired cerebral vasodilation has been linked to reduced cognitive activity in older adults with depression. However, to date, limited studies have examined the relation between cognitive function and cerebrovascular function in otherwise healthy young adults with MDD. PURPOSE: We tested the hypothesis that greater hypercapnia-induced cerebral vasodilation would be related to greater fluid cognitive ability (i.e., the capacity to process and integrate new information) in young adults with MDD. METHODS: Ten adults with MDD (non-medicated; age: 22±2 yrs: body mass index: 22.8±4.5 kg/m2; education level: all enrolled in a four-year university) participated. Cognitive function was assessed via the NIH Toolbox Cognitive Function Battery (iPad). A composite fluid cognitive ability score was derived from the specific tests within the battery that measure fluid ability [e.g., Flanker, Dimensional Change Cart Sort (DCCS)]; an age-correct standard T-score of 100 indicates ability that is average compared with national data. Beat-to-beat mean arterial pressure (MAP; finger photoplethysmography), middle cerebral artery blood velocity (MCAv; transcranial Doppler ultrasound), and end-tidal carbon dioxide concentration (PETCO2; capnograph) were continuously measured during normocapnic baseline and during rebreathing-induced hypercapnia. The hypercapnia-induced (∆PETCO2=9 mmHg) increase in cerebral vascular conductance index (∆CVCi=MCAv/MAP) was used as an index of cerebral vasodilatory reactivity. RESULTS: Hypercapnia elicited an increase in CVCi in all subjects (mean: 30±12%; range: 18-60%). The age-corrected composite fluid cognitive ability standard score was 100±15 (range: 79-119). The increase in CVCi was not related to fluid cognitive ability (slope=-0.12±0.3; r2=0.02, p=0.67). In addition, the increase in CVCi was not related to either the age-corrected standard score for the Flanker task (slope=-0.38±0.4; r2=0.12, p=0.32) or for the DCCS task (slope=0.09±0.3; r2=0.02, p=0.72), both of which specifically measure executive function. CONCLUSION: These preliminary data suggest that cerebral vasodilatory reactivity to a hypercapnic stimulus is not related to fluid cognitive function in otherwise healthy college-aged adults with MDD

Biology and ecology of the invasive lionfishes, Pterois miles and Pterois volitans

The Indo-Pacific lionfishes, Pterois miles and P. volitans, are now established along the U.S. southeast coast, Bermuda, Bahamas, and are becoming established in the Caribbean. While these lionfish are popular in the aquarium trade, their biology and ecology are poorly understood in their native range. Given the rapid establishment and potential adverse impacts of these invaders, comprehensive studies of their biology and ecology are warranted. Here we provide a synopsis of lionfish biology and ecology including invasion chronology, taxonomy, local abundance, reproduction, early life history and dispersal, venomology, feeding ecology, parasitology, potential impacts, and control and management. This information was collected through review of the primary literature and published reports and by summarizing current observations. Suggestions for future research on invasive lionfish in their invaded regions are provided