The Wilson-Garnjobst heterokaryon incompatibility tester strains of Neurospora crassa contain modifiers which influence growth rate of heterokaryons and distort segregation ratios.

Recent interest and accelerated research into the genetics of heterokaryon incompatibility (HI) in Neurospora crassa has led to increased use of the original Wilson-Garnjobst HI tester strains available from FGSC (1994 Catalog of Strains, Part VII.D.1.). We have found inconsistencies and abnormalities in both growth of heterokaryons and segregation of markers in crosses using these strains. First noticed was a lack of vigor and incomplete complementation of markers in forced heterokaryons when compared to compatible heterokaryons with known Oak Ridge (OR) background. Secondly, skewed allele ratios were recorded in crosses between the Wilson-Garnjobst strains and strains with OR background. Perkins and Bjorkman raised a cautionary note about these strains (1978 Neurospora Newsl. 25:24-25), however, they concentrated primarily on the scot mutant present in these and other strains originating from the Rockefeller-Lindegren (RL) background. We have attempted to further characterize the erratic behavior of Wilson-Garnjobst strains and determine if the scot mutant or other modifiers of HI are responsible

Relationships Between Indices of Macrovascular and Microvascular Function in Young, Black Women

Blacks (BL) exhibit an exaggerated prevalence of and mortality from cardiovascular disease (CVD) relative to other populations. Macro- and microvascular dysfunction is often a hallmark of heightened CVD risk, with both demonstrated in BL. However, data regarding this dysfunction remains sparse, particularly in BL women. Common indices of vascular function include flow-mediated dilation (FMD) and reactive hyperemia (RH) following a brief period of suprasystolic cuff occlusion and cutaneous thermal reactivity to local heating (LH). However, the relationship between these indices has not been established in BL women. PURPOSE: The present study aimed to test the relationship between indices of vascular function in BL women as assessed by FMD, RH, and LH. METHODS: To test this hypothesis, 6 white women (WW) and 6 BW (age: 22±2 vs. 21±3, respectively) were studied. FMD and RH were assessed following a period of suprasystolic cuff occlusion. Briefly, a rapid inflation cuff was secured just distal to the antecubital fossa for arterial occlusion. Blood velocity (Vmean; cm ∙ s-1) and vessel diameter (d; mm) were measured continuously via high-resolution, duplex Doppler ultrasound during a 2-min baseline, 5-min of cuff occlusion, and 3-min of recovery. FMD was determined as the percent dilation from baseline (%FMD) while RH was determined as the peak and area under the curve (AUC) responses for shear rate (8 ∙ Vmean ∙ d-1) and blood flow (Vmean ∙ π ∙ (d ∙ 20-1)2 ∙ 60). Cutaneous thermal reactivity was assessed using laser-Doppler flowmetry during a standard LH protocol and reported as cutaneous vascular conductance (CVC; red blood cell flux/mean arterial pressure). Following a baseline with local skin temperature clamped at 33°C, a 39°C heat stimulus was applied to induce cutaneous vasodilation for ~30-min. The sustained vasodilation at the end of heating is predominantly nitric oxide mediated and provides an index of microvascular function. As the LH component served as part of a larger intradermal microdialysis protocol, maximal blood flow responses were elicited via combined intradermal sodium nitroprusside (28mM) infusion and 43°C heating. CVC during the 39°C plateau was normalized to maximal CVC (%CVCmax) to account for intersite variability. Pearson correlations were then performed between the FMD, RH, and LH responses. RESULTS: Significant relationships were observed between %FMD and shear AUC (r = 0.89; P = 0.02), and blood flow AUC (r = 0.92; P = 0.01) in WW, but not in BW (r = 0.63; P = 0.18 and r = -0.24; P = 0.65, respectively). However, neither FMD nor RH correlated with the cutaneous blood flow responses to LH (P \u3e 0.05) in either WW or BW. CONCLUSION: These preliminary data suggest that FMD is highly correlated to some indices of RH in WW, but that this relationship does not hold in BW. Further, there appears to be no relationship between microvascular function as assessed by RH and LH in either population

Identification of a novel transport system in Borrelia burgdorferi that links the inner and outer membranes

Borrelia burgdorferi, the spirochete that causes Lyme disease, is a diderm organism that is similar to Gram-negative organisms in that it contains both an inner and outer membrane. Unlike typical Gram-negative organisms, however, B. burgdorferi lacks lipopolysaccharide (LPS). Using computational genome analyses and structural modeling, we identified a transport system containing six proteins in B. burgdorferi that are all orthologs to proteins found in the lipopolysaccharide transport (LPT) system that links the inner and outer membranes of Gram-negative organisms and is responsible for placing LPS on the surface of these organisms. While B. burgdorferi does not contain LPS, it does encode over 100 different surface-exposed lipoproteins and several major glycolipids, which like LPS are also highly amphiphilic molecules, though no system to transport these molecules to the borrelial surface is known. Accordingly, experiments supplemented by molecular modeling were undertaken to determine whether the orthologous LPT system identified in B. burgdorferi could transport lipoproteins and/or glycolipids to the borrelial outer membrane. Our combined observations strongly suggest that the LPT transport system does not transport lipoproteins to the surface. Molecular dynamic modeling, however, suggests that the borrelial LPT system could transport borrelial glycolipids to the outer membrane

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

Central Blood Pressure and Peripheral Reactive Vasodilation in Plant-Based and Typical Dieting African Americans

African American individuals (AA) face higher mortality rates from cardiovascular disease than Americans from other racial/ethnic backgrounds. The cause of this health disparity is multifactorial and is in part related to impaired vascular function as well as other variables including diet and numerous socioeconomic factors. Diets rich in whole plant foods and low in animal products may protect blood vessels through their high antioxidant capacity and low inflammatory load. PURPOSE: The purpose of this study was to test the hypothesis that AA adhering to a 100% plant-based (vegan) diet (PBD) would have a more favorable dietary intake of several key nutrients and more optimal blood cholesterol, which would contribute to better blood pressure and peripheral reactive vasodilation relative to AA following a typical American diet (TAD). METHODS: Seventeen AA participated in the study. Of them, 8 (5 female; age: 25±2 years; BMI: 23.4±1.4 kg/m2) were following a PBD for 2.5±0.3 years and 9 (5 female; age: 21±1 years; BMI: 25.3±2.1 kg/m2) were following a TAD. A fasting venous blood draw was performed to assess blood lipids. Participants completed a comprehensive diet questionnaire (DHQIII, NIH). Peripheral and central blood pressures were measured via the SphygmoCor system (AtCor Medical). Brachial artery flow-mediated dilation (FMD) and reactive hyperemia (RH) were assessed via well-established procedures. Briefly, 2 min baseline measurements of brachial artery diameter and blood velocity were taken via Doppler ultrasound before a forearm cuff was inflated to 220 mmHg for 5 min. Post-occlusion data were recorded for 3 min. Measurement of baseline to peak post-occlusion brachial artery diameter and blood velocity were performed by pairing a video capture system (Elgato) with edge-detection and blood velocity-tracking software (Quipu). RESULTS: PBD AA consumed more dark green vegetables and whole grains and less cholesterol than TAD AA (p\u3c.05 for all). Consumption of sodium, potassium, and vitamins C & E was not different between groups (p\u3e.05 for all). Total (TC) and low-density lipoprotein (LDL-C) blood cholesterol concentrations were lower in PBD AA relative to TAD AA (TC: 136±9 vs. 174±12 mg/dl; LDL-C: 77±6 vs. 106±11 mg/dl; respectively; p\u3c.05 for both). Resting brachial (b) and central (c) mean arterial blood pressures (MAP) were lower in PBD AA relative to TAD AA (bMAP: 85±2 vs. 91±2 mmHg; cMAP: 80±2 vs. 87±2 mmHg; respectively; p\u3c.05 for both). There were no differences between groups in FMD nor RH (p\u3e.05 for all). FMD and FMD/shear rate were 7.7±0.8% and 0.33±0.05 au in PBD AA and 6.2±0.9% and 0.27±0.03 au in TAD AA, respectively. For RH, the percentage change in blood velocity and flow were 1441±479% and 1425±466% in PBD AA and 707±495% and 671±76% in TAD AA, respectively. CONCLUSION: These preliminary data suggest that a diet rich in whole plant foods but devoid of animal products may be associated with healthier blood cholesterol and peripheral and central blood pressures in AA but that these differences may not yet be translating to differences in peripheral reactive 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

Sympathetically-Mediated Cutaneous Vasoconstriction Is Similar Between Non-Hispanic Black and White Individuals

Cardiovascular disease (CVD) prevalence is highest in non-Hispanic Black (BL) individuals compared to any other race. The mechanisms responsible remain incompletely understood and can be impacted by several environmental, psychosocial, and socioeconomic factors. A major contributing factor to elevated CVD risk/prevalence in the BL population is altered vascular function, which could be attributed to an exaggerated vasoconstrictor response to efferent sympathetic activity (i.e., sympathetic vascular transduction). Previous data from our group demonstrates heightened sympathetic vascular transduction in the peripheral vasculature of BL males. However, whether sympathetically-mediated vasoconstriction is exaggerated in the cutaneous circulation of BL individuals remains unknown. PURPOSE: This study tested the hypothesis that BL individuals exhibit exaggerated vasoconstriction to intra-dermal infusions of the α-adrenoreceptor agonist norepinephrine (NE) relative to White (WH) individuals. METHODS: In this study, young, healthy college-aged BL (n=13; 6 females) and WH (n=10; 4 females) individuals participated. Participants were instrumented with an intradermal microdialysis membrane in the dorsal forearm. Red blood cell flux was continuously assessed via laser Doppler flowmetry before (baseline) and during incrementally stronger infusions of NE (10-8 M – 10-2 M; 6 min/dose). Data were analyzed as a relative (i.e., percent) reduction in cutaneous vascular conductance (CVC: flux/MAP) compared to the pre-infusion baseline. RESULTS: NE caused a dose-dependent reduction in CVC in both groups (P\u3c0.001). There was no difference between the BL and WH individuals (P=0.37) nor was there a race x dose interaction (P=0.84). Similarly, when the data were separated by sex there was no difference between BL and WH males (P=0.56) or females (P=0.26). CONCLUSION: Vasoconstrictor responsiveness to α-adrenoreceptor activation was similar between BL and WH individuals. These data suggest that the cutaneous circulation may exhibit divergent sympathically-mediated vasoconstrictor responsiveness relative to other peripheral vascular beds in BL individuals

Cutaneous and Muscle Reactive Hyperemia in Young Adults with Major Depressive Disorder

The reactive hyperemic vasodilatory response to a brief period of tissue ischemia provides an index of microvascular function and is an independent predictor of cardiovascular morbidity and mortality. As such, reactive hyperemia is a non-invasive technique that is commonly utilized to provide an index of vascular health in various patient groups. Major depressive disorder (MDD), a non-traditional risk factor for cardiovascular disease (CVD), has been associated with blunted reactive hyperemia, though this is not a universal finding. Further, to date, the quantification of the reactive hyperemic response in adults with MDD has been limited to the forearm muscle, assessed as Doppler ultrasound derived blood velocity in the brachial artery following a period of suprasystolic cuff occlusion. PURPOSE: Here, we sought to more comprehensively assess microvascular reactive hyperemia in otherwise healthy young adults with MDD. We tested the hypothesis that both muscle and cutaneous vasodilation would be blunted in adults with MDD compared to non-depressed young adults. METHODS: Nine healthy adults (HA; age: 22±2 yrs: body mass index: 26.5 ± 1.8 kg/m2) and ten adults with MDD (non-medicated; age: 22±2 yrs: body mass index: 22.6 ± 4.4 kg/m2) participated. Forearm reactive hyperemia was assessed as the increase in blood velocity in the brachial artery following 5-min of suprasystolic cuff occlusion (distal to the olecranon process). In a subset of adults (n=5 HA; n=4 MDD), cutaneous reactive hyperemia was concurrently assessed via laser Doppler flowmetry-derived flux (perfusion units; PU). Peak and total (area-under-the-curve; AUC) reactive hyperemia were quantified for each methodological approach. RESULTS: Neither the brachial artery Doppler ultrasound-derived peak (HA: 1020±383 vs. MDD: 950±239 s-1; p=0.65) nor the total blood flow (HA: 284±77 vs. MDD: 233±153 a.u.; p=0.41) reactive hyperemic response was different between groups. Further, there were no group differences in cutaneous reactive hyperemia (peak: 83±37 HA vs. 79±15 PU MDD, p=0.85; AUC: 8764±2273 HA vs. 8935±1439 a.u. MDD; p=0.90). CONCLUSION: These preliminary data indicate that neither the muscle nor cutaneous vasodilatory response to a brief period of tissue ischemia is blunted in young adults with MDD, suggesting preserved microvascular function

Tromp1, a putative rare outer membrane protein, is anchored by an uncleaved signal sequence to the Treponema pallidum cytoplasmic membrane.

Treponema pallidum rare outer membrane protein 1 (Tromp1) has extensive sequence homology with substrate-binding proteins of ATP-binding cassette transporters. Because such proteins typically are periplasmic or cytoplasmic membrane associated, experiments were conducted to clarify Tromp1's physicochemical properties and cellular location in T. pallidum. Comparison of the sodium dodecyl sulfate-polyacrylamide gel electrophoresis mobilities of (i) native Tromp1 and Tromp1 synthesized by coupled in vitro transcription-translation and (ii) native Tromp1 and recombinant Tromp1 lacking the N-terminal signal sequence revealed that the native protein is not processed. Other studies demonstrated that recombinant Tromp1 lacks three basic porin-like properties: (i) the ability to form aqueous channels in liposomes which permit the influx of small hydrophilic solutes, (ii) an extensive beta-sheet secondary structure, and (iii) amphiphilicity. Subsurface localization of native Tromp1 was demonstrated by immunofluorescence analysis of treponemes encapsulated in gel microdroplets, while opsonization assays failed to detect surface-exposed Tromp1. Incubation of motile treponemes with 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)-diazarine, a photoactivatable, lipophilic probe, also did not result in the detection of Tromp1 within the outer membranes of intact treponemes but, instead, resulted in the labeling of a basic 30.5-kDa presumptive outer membrane protein. Finally, analysis of fractionated treponemes revealed that native Tromp1 is associated predominantly with cell cylinders. These findings comprise a body of evidence that Tromp1 actually is anchored by an uncleaved signal sequence to the periplasmic face of the T. pallidum cytoplasmic membrane, where it likely subserves a transport-related function

Invasive Lionfish Drive Atlantic Coral Reef Fish Declines

Indo-Pacific lionfish (Pterois volitans and P. miles) have spread swiftly across the Western Atlantic, producing a marine predator invasion of unparalleled speed and magnitude. There is growing concern that lionfish will affect the structure and function of invaded marine ecosystems, however detrimental impacts on natural communities have yet to be measured. Here we document the response of native fish communities to predation by lionfish populations on nine coral reefs off New Providence Island, Bahamas. We assessed lionfish diet through stomach contents analysis, and quantified changes in fish biomass through visual surveys of lionfish and native fishes at the sites over time. Lionfish abundance increased rapidly between 2004 and 2010, by which time lionfish comprised nearly 40% of the total predator biomass in the system. The increase in lionfish abundance coincided with a 65% decline in the biomass of the lionfish's 42 Atlantic prey fishes in just two years. Without prompt action to control increasing lionfish populations, similar effects across the region may have long-term negative implications for the structure of Atlantic marine communities, as well as the societies and economies that depend on them