Cryptic introgressions contribute to transgressive segregation for early blight resistance in tomato.

KEY MESSAGE: We identified cryptic early blight resistance introgressions in tomato breeding lines and demonstrated efficient genotypic selection for resistance in the context of a tomato breeding program. Early blight is a widespread and problematic disease affecting tomatoes (Solanum lycopersicum). Caused by the fungal pathogen Alternaria linariae (syn. A. tomatophila), symptoms include lesions on tomato stems, fruit, and foliage, often resulting in yield losses. Breeding tomatoes with genetic resistance would enhance production sustainability. Using cross-market breeding populations, we identified several quantitative trait loci (QTL) associated with early blight resistance. Early blight resistance putatively derived from 'Campbell 1943' was confirmed in modern fresh market tomato breeding lines. This resistance offered substantial protection against early blight stem lesions (collar rot) and moderate protection from defoliation. A distinctive and potentially novel form of early blight foliar resistance was discovered in a processing tomato breeding line and is probably derived from S. pimpinellifolium via 'Hawaii 7998'. Additional field trials validated the three most promising large-effect QTL, EB-1.2, EB-5, and EB-9. Resistance effects for EB-5 and EB-9 were consistent across breeding populations and environments, while EB-1.2's effect was population specific. Using genome-wide marker-assisted backcrossing, we developed fresh market tomato lines that were near-isogenic for early blight QTL. Resistance in these lines was largely mediated by just two QTL, EB-5 and EB-9, that together captured 49.0 and 68.7% of the defoliation and stem lesion variance, respectively. Our work showcases the value of mining cryptic introgressions in tomato lines, and across market classes, for use as additional sources of disease resistance.

A study of human papillomavirus on vaginally inserted sex toys, before and after cleaning, among women who have sex with women and men.

OBJECTIVES: The objective of the study was to determine the potential of human papillomavirus (HPV) transmission via shared sex toys, and determine whether cleaning practices implemented by the study participants were effective. METHODS: Vibrator 1 was composed of thermoplastic elastomer. Vibrator 2 was composed of silicone. Twelve women, recruited from a university, used each vibrator on separate occasions and provided self-collected vaginal and vibrator samples (obtained from the vibrator shaft and handle), collected immediately after use, immediately after cleaning with a commercially available cleaner, and 24 h after cleaning. Vaginal and vibrator samples were assessed for HPV DNA by the Roche Linear Array HPV Genotyping Test. RESULTS: HPV was detected in the vaginal samples of 9/12 (75%) women. Vibrator 1 shaft swabs were HPV positive before cleaning in 89% (8/9), immediately after cleaning in 56% (5/9), and 24 h after cleaning in 40% (2/5) of those that were HPV positive immediately after cleaning. Vibrator 2 shaft swabs were HPV positive before cleaning in 67% (6/9), immediately after cleaning in 44% (4/9), and 24 h after cleaning in none. CONCLUSIONS: HPV was detected on at least one vibrator immediately after use in the women with vaginal HPV. This supports the potential for HPV transmission via shared sex toy use, and is additionally supported by continued detection of HPV up to 24 h after standard cleaning. The data add to understanding of the range of sexual behaviours associated with HPV transmission, and the need for evidence-based recommendations for sex toy cleaning.

Uptake of 17ß-trenbolone and subsequent metabolite trendione by the pinto bean plant (Phaseolus vulgaris).

Manure from livestock feeding operations is commonly applied to agricultural fields as an alternative to commercial fertilizers. Trenbolone acetate (TbA) is a synthetic growth promoter frequently utilized in beef cattle feeding operations. Metabolites of TbA can be present in manure and subsequently applied to fields. Fate ofTbA metabolites 17ß-trenbolone (17ßTb), 17α-trenbolone (17αTb), and trendione (TbO) have been assessed in manure and soils, but plant uptake in agricultural fields is not fully understood. The objective of this study was to investigate potential plant uptake and biotransformation of 17ßTb using the pinto bean plant (Phaseolus vulgaris). Vegetated (n=20) and control sands (n=16) were amended with 17ßTb at a level of 1µg/g once per week for a total of four weeks. Sand, above-ground plant portion and below-ground plant portion were collected each week and then analyzed for 17ßTb, 17αTb, and TbO. By week four, low concentrations of 17ßTb (10±4.9µg/g fresh weight) were taken up into the roots of plants and, to a much lesser extent, translocated throughout the plant (0.04±0.02µg/g fresh weight). Extensive transformation of 17ßTb to the metabolite trendione (TbO) occurred in vegetated sand, while minimal TbO was detected in control sand. These results suggest the biotransformation of 17ßTb to TbO is predominantly through microbial degradation. Trenbolone (Tb) metabolites can then be taken up into plants but remain concentrated in the roots with only slight translocation to above ground portions of the plant. After four weeks, maximum observed concentrations of total Tb (parent+metabolites) in fresh plant tissues were 33.0µg/g in roots and 0.25µg/g in leaves. No phytotoxicity was observed to pinto bean plants throughout the four week study.

Accumulation and effects of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) exposure in the green anole (Anolis carolinensis).

Environmental contamination by energetic compounds is an increasing international concern, although little is known of their accumulation in and affect on wildlife. Reptiles are often good models for contaminants studies due to natural history traits that increase their potential for exposure. We report a study to assess accumulation and effects of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX, High Melting Explosive) in green anoles (Anolis carolinensis). Acute oral toxicity (LD(50)) was estimated to exceed 2000 mg/kg body weight in adult male and female anoles using a standard up-and-down method. Accumulation of HMX was assessed in adult females via dietary exposure and into eggs by two routes (directly from the soil and via maternal transfer). HMX readily accumulated into adult females in a dose-dependent manner and into eggs following both exposure pathways. However, total HMX in soil-exposed eggs was up to 40-times greater than those exposed via maternal transfer. Although there was a suggestion of an HMX-induced reduction in body weight in adult females, overall there were no effects observed over the 12 week exposure period. The only significant effect on eggs was a 50% reduction in hatching success for eggs exposed to 2000 mg/kg HMX in the soil during incubation. Growth and survival of hatchlings was not affected by HMX exposure. Our results demonstrate that HMX accumulates through the food chain and into eggs from the soil, but likely poses minimal threat to lizards except to hatching success in eggs incubated in soils with HMX levels near maximum environmental concentrations.

Control of complex behavior by astrocytes and microglia.

Evidence that glial cells influence behavior has been gaining a steady foothold in scientific literature. Out of the five main subtypes of glial cells in the brain, astrocytes and microglia have received an outsized share of attention with regard to shaping a wide spectrum of behavioral phenomena and there is growing appreciation that the signals intrinsic to these cells as well as their interactions with surrounding neurons reflect behavioral history in a brain region-specific manner. Considerable regional diversity of glial cell phenotypes is beginning to be recognized and may contribute to behavioral outcomes arising from circuit-specific computations within and across discrete brain nuclei. Here, we summarize current knowledge on the impact of astrocyte and microglia activity on behavioral outcomes, with a specific focus on brain areas relevant to higher cognitive control, reward-seeking, and circadian regulation.

Induction of self-tolerance in T cells but not B cells of transgenic mice expressing little self antigen.

Self-tolerance to a transgene-encoded protein, hen egg lysozyme, was examined in the T and B cell repertoires of a series of lines of transgenic mice that expressed different serum concentrations of soluble lysozyme. T cells were tolerant in all lines in which lysozyme was expressed irrespective of the antigen concentration, whereas B cell tolerance did not occur when the serum lysozyme concentration was less than 1.5 nanograms per milliliter (0.1 nM). Induction of elevated transgene expression could restore B cell tolerance. These findings support the hypothesis that autoimmune disease may in some instances arise through a bypass of T cell tolerance.

The structural basis of lipid interactions in lipovitellin, a soluble lipoprotein.

BACKGROUND: The conformation and assembly of lipoproteins, protein containing large amounts of noncovalently bound lipid, is poorly understood. Lipoproteins present an unusual challenge as they often contain varying loads of lipid and are not readily crystallized. Lipovitellin is a large crystallizable oocyte protein of approximately 1300 residues that contains about 16% w/w lipid. Lipovitellin contains two large domains that appear to be conserved in both microsomal triglyceride transfer protein and apolipoprotein B-100. To gain insight into the conformation of a lipoprotein and the potential modes of binding of both neutral and phospholipid, the crystal structure of lamprey lipovitellin has been determined. RESULTS: We report here the refined crystal structure of lipovitellin at 2.8 A resolution. The structure contains 1129 amino acid residues located on five peptide chains, one 40-atom phosphatidylcholine, and one 13-atom hydrocarbon chain. The protein contains a funnel-shaped cavity formed primarily by two beta sheets and lined predominantly by hydrophobic residues. CONCLUSIONS: Using the crystal structure as a template, a model for the bound lipid is proposed. The lipid-binding cavity is formed primarily by a single-thickness beta-sheet structure which is stabilized by bound lipid. This cavity appears to be flexible, allowing lipid to be loaded or unloaded.

Tumorigenicity of sodium ascorbate in male rats.

Sodium ascorbate, like other sodium salts such as saccharin, glutamate, and bicarbonate, produces urinary alterations when fed at high doses to rats, which results in mild superficial urothelial cytotoxicity and regeneration but not tumors in a standard 2-year bioassay. Sodium saccharin was shown to produce a low incidence of bladder tumors in rats if administered in a two-generation bioassay. In the present study, we evaluated sodium ascorbate in a two-generation bioassay that involved feeding to the male and female parental F344 rats for 4 weeks before mating, feeding the dams during gestation and lactation, and then feeding the weaned (at 28 days of age) male F1 generation rats for the remainder of their lifetime (up to 128 weeks of the experiment). Dietary levels of 1.0, 5.0, and 7.0% sodium ascorbate were tested. At 5.0 and 7.0% sodium ascorbate, there was an increase in urinary bladder urothelial papillary and nodular hyperplasia and the induction of a few papillomas and carcinomas. There was a dose-responsive increase in renal pelvic calcification and hyperplasia and inhibition of the aging nephropathy of rats even at the level of 1% sodium ascorbate. Because the short-term urothelial effects of sodium ascorbate in rats are inhibited by treatments producing urinary acidification to pH < 6.0, we coadministered high doses of long-term NH4Cl to groups of rats with 5.0 or 7.0% sodium ascorbate to evaluate the long-term effects. The combination of 7.0% sodium ascorbate plus 2.78% NH4Cl in the diet was toxic, and the group was terminated early during the course of the experiment. The group fed 5.0% sodium ascorbate plus 2.04% NH4Cl showed complete inhibition of the urothelial effects of sodium ascorbate and significant inhibition of its renal effects. We also demonstrated the presence of a calcium phosphate-containing urinary precipitate in rats fed sodium ascorbate at all doses, in a dose-responsive manner. The formation of the precipitate was inhibited by coadministration with NH4Cl. The proliferative effects of sodium ascorbate on the male rat urinary tract in this study are similar to those seen with sodium saccharin when administered in a two-generation bioassay. Mechanistic information suggests that this is a high-dose, rat-specific phenomenon.

Crystallization and preliminary analysis of telokin, the C-terminal domain of myosin light chain kinase.

Telokin, an acidic protein related to the C-terminal portion of smooth muscle myosin light chain kinase from turkey gizzard has been crystallized in a form suitable for a high-resolution diffraction analysis. The crystals were grown from solutions of polyethylene glycol 8000 using the hanging-drop vapor diffusion method. They belong to the trigonal space group P3(1)21 or P3(2)21 with cell parameters a = 64.0 A, c = 59.4 A and diffract to at least 2.7 A resolution.

The structure of vitellogenin provides a molecular model for the assembly and secretion of atherogenic lipoproteins.

The assembly of atherogenic lipoproteins requires the formation in the endoplasmic reticulum of a complex between apolipoprotein (apo)B, a microsomal triglyceride transfer protein (MTP) and protein disulphide isomerase (PDI). Here we show by molecular modelling and mutagenesis that the globular amino-terminal regions of apoB and MTP are closely related in structure to the ancient egg yolk storage protein, vitellogenin (VTG). In the MTP complex, conserved structural motifs that form the reciprocal homodimerization interfaces in VTG are re-utilized by MTP to form a stable heterodimer with PDI, which anchors MTP at the site of apoB translocation, and to associate with apoB and initiate lipid transfer. The structural and functional evolution of the VTGs provides a unifying scheme for the invertebrate origins of the major vertebrate lipid transport system.

Human CD4+ T-cell epitope repertoire on the C2 domain of coagulation factor VIII.

Approximately 25% of severe hemophilia A patients develop antibodies (Ab) that neutralize the procoagulant function of factor (F)VIII (inhibitors). Autoimmune FVIII inhibitors may develop in individuals without congenital FVIII deficiency and cause acquired hemophilia. Low titers of anti-FVIII Ab may be present in hemophilia A patients without inhibitors and in healthy blood donors. FVIII-specific CD4+ T-cells drive the synthesis of anti-FVIII Ab. We examined the epitope repertoire of CD4+ T-cells from 15 healthy subjects, 10 hemophilia A patients without inhibitors, 11 hemophilia A patients with inhibitors, and six acquired hemophilia patients. Blood CD4+ T-cells were challenged in proliferation assays with a panel 16 overlapping synthetic peptides, spanning the sequence of the FVIII C2 domain. The sequence region 2291-2330 contained the most frequently and strongly recognized peptides in each of the four subject groups. Crystallographic B factor data and the location of these peptides within the three-dimensional structure of the C2 domain confirm that this region has a high degree of solvent exposure and flexibility within the peptide backbone, which are structural features typical of immunodominant universal CD4+ epitopes. Furthermore, this sequence region overlaps inhibitor-binding sites, suggesting that CD4+ T-cells recognizing peptide sequences within this region might be involved in inhibitor synthesis. The sequence regions 2191-2210 (recognized strongly by each study group except hemophilia A patients with inhibitors) and 2241-2290 (recognized primarily by acquired hemophilia patients and healthy subjects) share the same structural features, and also overlap inhibitor-binding sites. Although similar, there appear to be important differences in the CD4+ epitope repertoires of congenital and acquired hemophilia patients.

Epitope repertoire of human CD4(+) T cells on the A3 domain of coagulation factor VIII.

Severe hemophilia A patients treated with factor (F)VIII may develop antibodies (Ab) that block FVIII function (inhibitors). Autoimmune inhibitors may develop in subjects without congenital hemophilia, and cause acquired hemophilia. Hemophiliacs without inhibitors and healthy subjects may also have small amounts of antiFVIII Ab. FVIII-specific CD4(+) T cells induce antiFVIII Ab synthesis. Here, we have examined their epitope repertoire in hemophilia patients and healthy subjects. We used overlapping synthetic peptides, spanning the sequence of the FVIII A3 domain, to challenge blood CD4(+) T cells in proliferation assays. The epitopes recognized in hemophilia A patients with or without inhibitors, acquired hemophilia patients, or healthy subjects overlapped, yet had characteristic differences. Most members of one or more study groups recognized the sequence regions 1691-1710, 1801-1820, 1831-1850, and 1941-60. In the proposed three-dimensional structure of the A3 domain, these sequences are largely exposed to the solvent and flanked by flexible sequence loops: these are structural features characteristic of 'universal' CD4(+) T epitopes. Hemophilia A patients with inhibitors recognized prominently only the sequence 1801-1820, which overlaps a known inhibitor binding site. This is consistent with the possibility that CD4(+) T cells recognizing epitopes within residues 1801-1820 have a role in inducing inhibitor synthesis. In contrast, CD4(+) T cells sensitized to sequences 1691-1710 and 1941-60, which are recognized by healthy subjects and hemophilia A patients without inhibitors, might curb inhibitor synthesis.

Nutritional regulation of insulin-like growth factor-I mRNA expression in barramundi, Lates calcarifer.

The effect of nutritional status on IGF-I mRNA expression in the liver and brain of juvenile barramundi (Lates calcarifer) was investigated. Fish were either fed a satiety ration (SAT) or starved (STV) for 6 weeks. Starved fish demonstrated significantly lower condition factor and hepatic IGF-I mRNA expression at 3 and 6 weeks, when compared with the SAT group. IGF-I mRNA expression in the brain was 10 fold lower than the liver and was not affected by ration size. These results suggest the liver is the major site of IGF-I mRNA synthesis and hepatic but not brain IGF-I mRNA expression is regulated by food availability in juvenile barramundi.

Immunoreactive and receptor-active insulin-like growth factor-I (IGF-I) and IGF-binding protein in blood plasma from the freshwater fish Macquaria ambigua (golden perch).

The presence of insulin-like growth factor-I (IGF-I)-related molecules and IGF-binding factors in blood from golden perch, Macquaria ambigua, an Australian native freshwater fish, was investigated. Serum was acidified to dissociate IGF and IGF-binding protein complexes that might be present, and fractionated by size-exclusion high-performance liquid chromatography at pH 2.8. Fractions were neutralized and their activities assessed by (i) an immunoassay for mammalian IGF-I which also detects chicken IGF-I but in which all known forms of IGF-II react very poorly, (ii) a receptor assay for IGF-II in which all known forms of IGF-I react poorly, and (iii) a type-I IGF receptor assay in which mammalian IGF-I and IGF-II polypeptides are amost equivalent. No IGF-II-like activity was detected. Three peaks of IGF-I-like activity were detected by IGF-I immunoassay and type-I IGF receptor assay. The major peak of activity was similar in molecular size to human IGF-binding protein-3, 45-55 kDa ('large IGF'), and a minor peak of activity which was similar in size to mammalian IGFs, 7.5 kDa. A third peak of activity was observed eluting at a time which indicates that it is a smaller molecule than any previously described IGF. The large IGF was temperature-sensitive, but was not a binding protein for 125I-labelled human IGF-I (hIGF-I). This material therefore was able to bind to anti-hIGF-I antibodies and to human type-I IGF receptors, and may represent the fish equivalent of mammalian prepro-IGFs.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulation of neuronal Na+, K+-ATPase by calcium.

The effect of calcium on ATP-phosphohydrolase activity of rat brain homogenates has been investigated. In both the presence and absence of the chelating agent EDTA, free calcium within the concentration range 1.2 x 10(-7) to 5.0 x 10(-4) moles/l consistently affected only the activity of Na+, K+-ATpase; the activities of Mg2+-ATPase and Na+-ATPase were essentially unchanged by Ca2+; Ca2+-ATPase could not be demonstrated. In either the presence or absence of EDTA, concentrations of free-Ca2+ above 3 x 10(-6) moles/l caused an inhibition of Na+,K+-ATPase activity. In the presence of EDTA, concentrations of free-Ca2+ below 3 x 10(-6) moles/l were ineffective at altering Na+, K+-ATPase activity but, in the absence of EDTA, free-Ca2+ in this concentration range caused a marked stimulation of the enzyme. Evidence is presented to show that the stimulation of Na+, K+-ATPase by calcium is modulated by the regulatory protein calmodulin. Since the stimulation occurs over the range of concentrations at which calcium would be expected to be encountered within the cell, it is suggested that this is the major physiological effect of calcium on Na+, K+-ATPase.

Commercial infant foods: content and composition.

The relative contribution of strained foods to total dietary caloric distribution is important when assessing the appropriateness of a particular food choice. Because protein intakes by most infants in the United States are generous, the high carbohydrate content of the typical strained food can be helpful in adjusting the distribution of calories. The fat content of most strained foods is low and those foods higher in fat are also comparatively high in protein content. Therefore it is difficult to find strained foods to contribute greater amounts of dietary fat without also increasing the percentage of calories in the form of protein. For this reason it is not possible to achieve a satisfactory distribution of calories in the diet of an infant fed skim milk. With the exception of home-prepared fruits with low sugar content, baby food prepared in the home will probably have a higher caloric density than commercial products. Care should be taken not to overfeed infants when feeding home-prepared baby foods. The appropriateness of United States baby foods for use in developing countries and a physiological rationale for age of introduction of strained foods were discussed. A basic need is to ensure that the strained foods of the future are formulated with emphasis given to nutritional need and least cost, as well as to mother's taste and to the manufacturer's profit.

DDE in eggs of two crocodile species from Belize.

Organochlorine (OC) residues were recently detected in nonviable Morelet's crocodile (Crocodylus moreletii) eggs from northern Belize. To further the assessment of contaminant exposure in Belizean crocodiles, nonviable Morelet's crocodile eggs (n = 11) from southern Belize and American crocodile (Crocodylus acutus) eggs (n = 12) from the coastal zones of Belize were screened for 20 OCs. Results indicated p,p-DDE to be the most prevalent OC (96% occurrence) in eggs examined, with concentrations ranging from 5 to 372 ng/g. These concentrations are similar to those observed in crocodile eggs (10-180 ng/g) from northern Belize. A general trend toward higher DDE concentrations in Morelet's crocodile eggs (mean = 103 ppb) compared with American crocodile eggs (mean = 31 ppb) was observed. However, this trend may be due to site-specific contamination rather than differences in interspecific susceptibility to chemical exposure. Other OCs detected in crocodile eggs included the parent compound, p,p-DDT, and its metabolite, p, p-DDD.

Organochlorine contaminants in Morelet's crocodile (Crocodylus moreletii) eggs from Belize.

Non-viable eggs of Morelet's crocodile (Crocodylus moreletii) were collected from Gold Button (GBL) and New River lagoons (NRL) in northern Belize and screened for organochlorine (OC) compounds using gas chromatography (GC) with electron capture detection (ECD). All egg samples from both lagoons (n = 24) tested positive for one or more OCs. Primary contaminants were p,p-DDE and methoxychlor, detected in 100% and 29% of the eggs examined, respectively. Concentrations of individual OC contaminants ranged from 1 ppb (ng chemical/g egg) to > 0.5 ppm (microgram chemical/g egg). Total concentrations of OCs (sum of all OCs) for one egg collected from a nest at GBL reached as high as 0.7 ppm. Sediment samples from both lagoons also tested positive for OCs (lindane, aldrin, methoxychlor, heptachlor epoxide, p,p-DDT, among others). Nest media (soil and plant material) collected from crocodile nests at GBL were positive for p,p-DDT, methoxychlor, aldrin, endosulfan II, and endrin aldehyde. Based on the 24 egg samples analyzed to date, crocodiles from both lagoons are being exposed to OCs. Such exposure may present a health threat to populations of crocodiles in Central America.

Medicine for a sick immunization system.

The United States has recently experienced a rise in the incidence of measles and other preventable infectious diseases. Studies have linked the problem to a growing number of inadequately vaccinated preschoolers. The Minnesota Department of Health estimates that only 61.4% of the state's 2-year-olds have completed the basic primary series on schedule. Coverage rates are worse in the Twin Cities, where the number of poor and minority "at-risk" children has skyrocketed in the last 10 years. Two different assessments in St. Paul revealed that only 24% to 32% of the 2-year-olds in the survey populations had received the basic series of immunizations. Public and private health care providers need to work together to eliminate barriers to immunization.