Intracellular colocalization of HAP1/STBs with steroid hormone receptors and its enhancement by a proteasome inhibitor

The stigmoid body (STB) is a cytoplasmic inclusion containing huntingtin-associated protein 1 (HAP1), and HAP1/STB formation is induced by transfection of the HAP1 gene into cultured cells. In the present study, we examined the intracellular colocalization of HAP1/STBs with steroid hormone receptors (SHRs), including the androgen receptor (AR), estrogen receptor, glucocorticoid receptor (GR), and mineralocorticoid receptor, in COS-7 cells cotransfected with HAP1 and each receptor. We found that C-terminal ligand-binding domains of all SHRs had potential for colocalization with HAP1/STBs, whereas only AR and GR were clearly colocalized with HAP1/STBs when each full-length SHR was coexpressed with HAP1. In addition, it appeared that HAP1/STBs did not disrupt GR and AR functions because the receptors on HAP1/STBs maintained nuclear translocation activity in response to their specific ligands. When the cells were treated with a proteasome inhibitor, GR and AR localized outside HAP1/STBs translocated into the nucleus, whereas the receptors colocalized with HAP1/STBs persisted in their colocalization even after treatment with their ligands. Therefore, HAP1/STBs may be involved in cytoplasmic modifications of the nuclear translocation of GR and AR in a ubiquitin–proteasome system.     

Characterization of (2S,2'R,3'R)-2-(2',3'-[3H]-Dicarboxycyclopropyl)glycine Binding in Rat Brain

Abstract: [(2S,2′R,3′R)-2-(2′,3′-[³H]Dicarboxycyclopropyl)glycine ([³H]DCG IV) binding was characterized in vitro in rat brain cortex homogenates and rat brain sections. In cortex homogenates, the binding was saturable and the saturation isotherm indicated the presence of a single binding site with a K_D value of 180 ± 33 nM and a B_max of 780 ± 70 fmol/mg of protein. The nonspecific binding, measured using 100 µM LY354740, was <30%. NMDA, AMPA, kainate, l (?)-threo-3-hydroxyaspartic acid, and (S)-3,5-dihydroxyphenylglycine were all inactive in [³H]DCG IV binding up to 1 mM. However, several compounds inhibited [³H]DCG IV binding in a concentration-dependent manner with the following rank order of potency: LY341495 = LY354740 > DCG IV = (2S,1′S,2′S)-2-(2-carboxycyclopropyl)glycine > (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid > (2S,1′S,2′S)-2-methyl-2-(2-carboxycyclopropyl)glycine > l -glutamate = ibotenate > quisqualate > (RS)-α-methyl-4-phosphonophenylglycine = l (+)-2-amino-3-phosphonopropionic acid > (S)-α-methyl-4-carboxyphenylglycine > (2S)-α-ethylglutamic acid > l (+)-2-amino-4-phosphonobutyric acid. N-Acetyl-l -aspartyl-l -glutamic acid inhibited the binding in a biphasic manner with an IC₅₀ of 0.2 µM for the high-affinity component. The binding was also affected by GTPγS, reducing agents, and CdCl₂. In parasagittal sections of rat brain, a high density of specific binding was observed in the accessory olfactory bulb, cortical regions (layers 1, 3, and 4 > 2, 5, and 6), caudate putamen, molecular layers of the hippocampus and dentate gyrus, subiculum, presubiculum, retrosplenial cortex, anteroventral thalamic nuclei, and cerebellar granular layer, reflecting its preferential (perhaps not exclusive) affinity for pre- and postsynaptic metabotropic glutamate mGlu2 receptors. Thus, the pharmacology, tissue distribution, and sensitivity to GTPγS show that [³H]DCG IV binding is probably to group II metabotropic glutamate receptors in rat brain.     

Chemolithoautotrophy in the marine,magnetotactic bacterial strains MV-1 and MV-2

Magnetite-producing magnetotactic bacteria collected from the oxic–anoxic transition zone of chemically stratified marine environments characterized by O₂/H₂S inverse double gradients, contained internal S-rich inclusions resembling elemental S globules, suggesting they oxidize reduced S compounds that could support autotrophy. Two strains of marine magnetotactic bacteria, MV-1 and MV-2, isolated from such sites grew in O₂-gradient media with H₂S or thiosulfate (S₂O₃^2–) as electron sources and O₂ as electron acceptor or anaerobically with S₂O₃^2– and N₂O as electron acceptor, with bicarbonate (HCO₃^–)/CO₂ as sole C source. Cells grown with H₂S contained S-rich inclusions. Cells oxidized S₂O₃^2– to sulfate (SO₄^2–). Both strains grew microaerobically with formate. Neither grew microaerobically with tetrathionate (S₄O₆^2–), methanol, or Fe²⁺ as FeS, or siderite (FeCO₃). Growth with S₂O₃^2– and radiolabeled ¹⁴C-HCO₃^– showed that cell C was derived from HCO₃^–/CO₂. Cell-free extracts showed ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity. Southern blot analyses indicated the presence of a form II RubisCO (cbbM) but no form I (cbbL) in both strains. cbbM and cbbQ, a putative post-translational activator of RubisCO, were identified in MV-1. MV-1 and MV-2 are thus chemolithoautotrophs that use the Calvin–Benson–Bassham pathway. cbbM was also identified in Magnetospirillum magnetotacticum. Thus, magnetotactic bacteria at the oxic–anoxic transition zone of chemically stratified aquatic environments are important in C cycling and primary productivity.     

Immunoreactivity of subunits of the (Na + K)-ATPase Cross-reactivity of the α,α+ and β forms in different organs and species

The immunologic cross-reactivity of the α and α+ forms of the large subunit and the β subunit of the (Na⁺ + K⁺)-ATPase from brain and kidney preparations was examined using rabbit antiserum prepared against the purified holo lamb kidney enzyme. As previously reported by Sweadner ((1979) J. Biol. Chem. 254, 6060–6067) phosphorylation of the large subunit of the (Na⁺ + K⁺)-ATPase in the presence of Na⁺, Mg²⁺, and [γ-³²P]ATP revealed that dog and, very likely, rat brain contain two forms of the large subunit (designated α and α+) while dog, rat, and lamb kidney contain only one form (α). The cross-reactivity of the α and α+ forms in these preparations was investigated by resolving the subunits by SDS-polyacrylamide gel electrophoresis. The separated polypeptides were transferred to unmodified nitrocellulose paper, and reacted with rabbit anti-lamb kidney serum, followed by detection of the antigen-antibody complex with ¹²⁵I-labeled protein A and autoradiography. By this method, the α and α+ forms of rat and dog brain, as well as the α form found in kidney, were shown to cross-react. In addition, membranes from human cerebral cortex were shown to contain two immunoreactive bands corresponding to the α and α+ forms of dog brain. In contrast, the brain of the insect Manduca sexta contains only one immunoreactive polypeptide with a molecular weight intermediate to the α and α+ forms of dog brain. The β subunit from lamb, dog and rat kidney and from dog and rat brain cross-reacts with anti-lamb kidney (Na⁺ + K⁺)-ATPase serum. The mobility of the β subunit from dog and rat brain on SDS-polyacrylamide electrophoresis gels is greater than the mobility of the β subunit from lamb, rat or dog kidney.     

HAP1 can sequester a subset of TBP in cytoplasmic inclusions via specific interaction with the conserved TBP<Subscript>CORE</Subscript>

Background  

Huntington's disease, spinal and bulbar muscular atrophy, and spinocerebellar ataxia 17 (SCA17) are caused by expansions in the polyglutamine (polyQ) repeats in Huntingtin protein (Htt), androgen receptor protein (AR), and TATA-binding protein (TBP), respectively. Htt-associated protein 1 (HAP1), a component of neuronal cytoplasmic stigmoid bodies (STBs), can sequester polyQ-expanded Htt and AR in STBs, thereby antagonizing formation of the nuclear aggregates associated with apoptotic neuron loss and disease progression.     

Conformations of peptides containing a chiral cyclic α, α‐disubstituted α‐amino acid within the sequence of Aib residues

A single chiral cyclic α,α‐disubstituted amino acid, (3S,4S)‐1‐amino‐(3,4‐dimethoxy)cyclopentanecarboxylic acid [(S,S)‐Ac₅c^dOM], was placed at the N‐terminal or C‐terminal positions of achiral α‐aminoisobutyric acid (Aib) peptide segments. The IR and ¹H NMR spectra indicated that the dominant conformations of two peptides Cbz‐[(S,S)‐Ac₅c^dOM]‐(Aib)₄‐OEt ( 1) and Cbz‐(Aib)₄‐[(S,S)‐Ac₅c^dOM]‐OMe (2) in solution were helical structures. X‐ray crystallographic analysis of 1 and 2 revealed that a left‐handed (M) 3₁₀‐helical structure was present in 1 and that a right‐handed (P) 3₁₀‐helical structure was present in 2 in their crystalline states. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.     

Characterization of SLFL1, a pollen-expressed F-box gene located in the Prunus S locus

The S locus and its flanking regions in the genus Prunus (Rosaceae) contain four pollen-expressed F-box genes. These genes contain the S locus F-box genes with low allelic sequence polymorphism genes 1, 2, and 3 (SLFL1, SLFL2, and SLFL3) as well as the putative pollen S gene, named the S haplotype-specific F-box protein gene (SFB). As much less information is available on the function of SLFLs than that of SFB, we analyzed the SLFLs of six S haplotypes of sweet cherry (Prunus avium) in this study. Genomic DNA blot analysis and the isolation of SLFL1 showed that the SLFL1 gene in a functional self-incompatible S ³ haplotype is deleted and only a partial sequence resembling SLFL1 is left in the S ³ locus region, suggesting that SLFL1 by itself is not directly involved in either the GSI reaction or pollen-tube growth. Genomic DNA blot analysis showed that there was no substantial modification or mutation in SLFL2 and SLFL3. A phylogenic analysis of F-box genes in the rosaceous S locus and its border regions showed that Prunus SLFLs were more closely related to maloid S locus F-box brothers than to Prunus SFBs. The functions of SLFLs and the evolution of self-incompatibility in Prunus are discussed based on these results. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. The nucleotide sequence data reported appear in the DDBJ, EMBL, and GenBank Nucleotide Sequence Databases under the accession numbers, AB360339, AB360340, AB360341, and AB360342, for SLFL1-S ¹ , SLFL1-S ² , SLFL1-S ⁵ , and SLFL1-S ⁶ , respectively.     

Intra-H-2 recombination inH-2b/H-2t1 heterozygotes in the mouse

Four cases of intra-H-2 recombination were detected during serological screening of 1066 backcross animals produced fromH-2^b/H-2^t1 heterozygous mice. Three of the intra-H-2 recombinants received theK region fromH-2^t1 and theD region from theH-2^b parental chromosome. The remaining recombinant received theK region from theH-2^b parental chromosome and theD region fromH-2^t1. Three of the four recombinants have been developed into inbred lines TBR2, TBR3, and TBR4 and were assigned the haplotype designations at², at³, and at⁴. Ss typing revealed that TBR2 and TBR3 originated fromK- S interval crossover events, while the remaining two recombinants resulted from crossing over in theS- D interval.     

Constrained C-terminal hexapeptide neurotensin analogues containing a 3-oxoindolizidine skeleton

Summary In order to enforce different spatial orientations in the C-terminal hexapeptide of neurotensin (NT_8–13) and to gain information about the importance of the 10–11 peptide bond for binding to NT receptors, the Pro¹⁰-Tyr¹¹ fragment has been replaced with (2R,8S,8aR)-, (2S,8S,8aR)-, (2S,8S,8aS)-, (2S,8R,8aS)- and (2R,8R,8aS)-8-amino-2-benzyl-3-oxoindolizidine-2-carboxylic acid. Molecular dynamics calculations and energy minimization studies have shown that, contrarily to the Pro-Tyr moiety, none of these indolizidines display a tendency to adopt type I and III -turns, but those having (8S,8aR) or (8R,8aS) stereochemistry essentially adopt extended conformations and the (8S,8aS) stereoisomer prefers a nonstandard folding. The four diastereomeric NT_8–13 analogues incorporating (8S,8aR) or (8R,8aS) indolizidines displayed binding affinities for the brain NT receptor similar to that of [Ala¹¹]-NT_8–13 and only five- to ninefold lower than that of the corresponding analogue, [Phe¹¹]NT_8–13. Although this slight decrease could be attributed to differences in conformational behavior between these constrained NT_8–13 analogues and [Phe¹¹]NT_8–13 or NT_8–13, it is not clear whether the -turn around Pro¹⁰-AA¹¹ (AA=Phe, Tyr) is conserved upon receptor binding. An excessive restriction in the motions of the aromatic side chain, imposed by the highly steric constraint of the indolizidine moiety, emerges as an alternative explanation. The findings reported here demonstrate the possibility of replacing the Pro¹⁰-Tyr¹¹ dipeptide in NT_8–13 with a non-peptide residue without affecting considerably the affinity for brain NT receptors.     

Circularly polarized luminescence of Eu(III) complexes with chiral 1,1′-bi-2-naphtol-derived bisphosphate ligands

The interest for lanthanide circularly polarized luminescence (CPL) has been quickly growing for 10 years. However, very few of these studies have involved correlation between the dissymmetry factor (g_lum) and the chemical modifications in a series of chiral ligands. Four polymeric compounds of Eu(III) were prepared by using a series of binaphtyl derivatives for which the size of the π system as well as the number of stereogenic elements (i.e., the binaphtyl moiety) are modulated. The resulting {[Eu(hfac)₃((S)/(R)-L^x)]}_n (x = 1 and 3) and {[Eu(hfac)₃((S,S,S)/(R,R,R)-L^x)]}_n (x = 2 and 4) have been characterized by powder X-ray diffraction by comparison with the X-ray structures on single crystal of the Dy(III) analogs. In solution, the structure of the complexes is deeply modified and becomes monomeric. The nature of the ligand induces change in the shape of the CPL spectra in CH₂Cl₂ solution. Furthermore, a large |g_lum| = 0.12 of the magnetic-dipole transition for the [Eu(hfac)₃((S,S,S)/(R,R,R)-L²)] complex involving the ligand with three stereogenic elements and an extended ?? system has been measured. This report also shows CPL measurements in solid state for the series of {[Eu(hfac)₃((S)/(R)-L^x)]}_n (x = 1 and 3) and {[Eu(hfac)₃((S,S,S)/(R,R,R)-L^x)]}_n (x = 2 and 4) polymers.     

Preparation of Single-Enantiomer Biofunctional Molecules with (S)-2-Methoxy-2-(1-naphthyl)propanoic Acid

(RS)-β-Ionol and (RS)-2-methyl-4-octanol were resolved by using (S)-2-methoxy-2-(1-naphthyl)propanoic acid [(S)-MαNP acid]. The specific stereochemistry of each MαNP ester was elucidated by 2D NMR analyses, and shielding by the 1-naphthyl group was observed in both the ¹H- and ¹³C-NMR spectra. Solvolysis of the individual (S)-MαNP esters gave four single-enantiomer alcohols. The normal-phase HPLC elution order of each MαNP ester is also discussed.     

Modulating the folding stability and ligand binding affinity of Pin1 WW domain by proline ring puckering

The pyrrolidine side chain makes proline play a unique role in protein structure and function. The C^γ ring pucker preference and the cis– trans peptidyl bond ratio can be mediated via stereoelectronic effects. Here we used a compact triple‐stranded antiparallel β‐sheet protein, the human Pin1 WW domain, to study the consequences of implanting a preorganized C^γ ring pucker on protein structure and function. The conserved Pro37 is a key residue involved in one hydrophobic core, plays an important role in the WW domain, and adopts a C^γ‐endo ring pucker in the native structure. Pro37 was replaced with C^γ‐exo biased pucker derivatives: (2S,4R)‐4‐hydroxyproline (4R‐Hyp), (2S,4R)‐4‐fluoroproline (4R‐Flp), (2S,4R)‐4‐methoxyproline (4R‐Mop), and C^γ‐endo biased pucker derivatives: (2S,4S)‐4‐hydroxyproline (4S‐hyp), (2S,4S)‐4‐fluoroproline (4S‐flp), (2S,4S)‐4‐methoxyproline (4S‐mop) to examine how a preorganized pucker affects the folding stability and ligand‐binding affinity. Circular dichroism measurements indicate that among the variants, only the one with 4S‐flp substitution (P37flp) is more stable than the wild type, suggesting that the stabilization effects originated from preorganization of the backbone conformation and the hydrophobicity of C? F group. Analysis of ligand‐binding affinity using isothermal titration calorimetry revealed that only P37flp has a stronger ligand affinity than the wild type, showing that 4S‐flp can stabilize the WW domain and increase its ligand affinity. Together we have used 4‐substituted proline derivatives and the WW domain to demonstrate that proline ring puckering can be a key factor in determining the folding stability of a protein but the choice of the derivative groups is also critical. Proteins 2014; 82:67–76. © 2013 Wiley Periodicals, Inc.     

Comparative genetic analysis of the Aegilops longissima and Ae. sharonensis genomes with common wheat

Aegilops longissima Schw. et Musch. (2n= 2x=14, S^lS^l) and Aegilops sharonensis Eig. (2n=2x=14, S^lS^l) are diploid species belonging to the section Sitopsis in the tribe Triticeae and potential donors of useful genes for wheat breeding. A comparative genetic map was constructed of the Ae. longissima genome, using RFLP probes with known location in wheat. A high degree of conserved colinearity was observed between the wild diploid and basic wheat genome, represented by the D genome of cultivated wheat. Chromosomes 1S^l, 2S^l, 3S^l, 5S^l and 6S^l are colinear with wheat chromosomes 1D, 2D, 3D, 5D and 6D, respectively. The analysis confirmed that chromosomes 4S^l and 7S^l are translocated relative to wheat. The short arms and major part of the long arms are homoeologous to most of wheat chromosomes 4D and 7D respectively, but the region corresponding to the distal segment of 7D was translocated from 7S^lL to the distal region of 4S^lL. The map and RFLP markers were then used to analyse the genomes and added chromosomes in a set of ’Chinese Spring’ (CS)/Ae. longissima chromosome additions. The study confirmed the availability of disomic CS/Ae. longissima addition lines for chromosomes 1S^l, 2S^l, 3S^l, 4S^l and 5S^l. An as yet unpublished set of Ae. sharonensis chromosome addition lines were also available for analysis. Due to the gametocidal nature of Ae. sharonensis chromosomes 2S^l and 4S^l, additions 1S^l, 3S^l, 5S^l, 6S^l and 7S^l were produced in a (4D)4S^l background, and 2S^l and 4S^l in a euploid wheat background. The analysis also confirmed that the 4/7 translocation found in Ae. longissima was not present in Ae. sharonensis although the two wild relatives of wheat are considered to be closely related. The phenotypes of the Ae. sharonensis addition lines are described in an Appendix. Received: 28 September 2000 / Accepted: 19 January 2001     

Precipitated,Coprecipitated, and Carbon–Mineral Sorbents for Isolation of Exracellular Catalase from Penicillium piceum F-648

The abilities of various sorbents to adsorb catalase (CAT; EC 1.11.1.6) from filtered culture liquid (FCL) of the fungus Penicillium piceum F-648 were compared. Potassium phosphate, hydroxyapatite (HAP), and coprecipitated sorbents containing calcium phosphate and magnesium hydroxide adsorbed extracellular CAT more efficiently than aluminum oxide, aluminum phosphate, or quartz sand. The enzyme was isolated from FCL of Penicillium piceum with the use of HAP and a binary coprecipitated sorbent, Ca₃(PO₄)₂ + Mg(OH)₂, 1 : 1 (CM). The CAT(CM) sample contained the least amount of protein admixture. Its spectra had absorption maximums at 279.6, 406.8 (Soret band), 540, 585, 636, and 703 nm and negative molar ellipticity minimums at 207 and 210–214 nm. The kinetic indices of the samples (K _M, V _max : K _M, and specific activity) were intricately dependent on the protein concentration in the reaction mixture. In dilute solutions, the K _M and specific activities of CAT(CM) and CAT(HAP) equaled 667 and 137 mM; 300.9 × 10⁴ and 30.0 × 10⁴ U/mg protein, respectively. The effective velocity constants of inactivation of CAT(HAP), CAT(CM), and FCL in the reaction of H₂O₂ decomposition increased dramatically after the dilution of samples. In the infinitely dilute solution, they were 4.30 × 10^–2, 6.46 × 10^–2, and 1.12 × 10^–2 s^–1, respectively.     

Cleavage of the Carboxyl-Terminus of LEACS2, a Tomato 1-Aminocyclopropane-1-Carboxylic Acid Synthase Isomer, by a 64-kDa Tomato Metalloprotease Produces a Truncated but Active Enzyme

1-Aminocyclopropane-1-carboxylic acid （ACC） synthase （ACS） is the principal enzyme in phytohormone ethylene biosynthesis. Previous studies have shown that the hypervariable C-terminus of ACS is proteolytically processed in vivo. However, the protease responsible for this has not yet been identified. In the present study, we investigated the processing of the 55-kDa full-length tomato ACS （LeACS2） into 52-, 50- and 49-kDa truncated isoforms in ripening tomato （Lycopersicon esculentum Mill. cv. Cooperation 903） fruit using the sodium dodecyl sulfate-boiling method. Meanwhile, an LeACS2-processing protease was purified via multi-step column chromatography from tomato fruit. Subsequent biochemical analysis of the 64-kDa purified protease revealed that it is a metalloprotease active at multiple cleavage sites within the hypervariable C-terminus of LeACS2. N-terminal sequencing and matrix-assisted laser desorption/ionization time-of-flight analysis indicated that the LeACS2-processing metalloprotease cleaves at the C-terminal sites Lys^438, Glu^447, Lys^448, Asn^456, Ser^460, Ser^462, Lys^463, and Leu^474, but does not cleave the N- terminus of LeACS2. Four C-terminus-deleted （26-50 amino acids） LeACS2 fusion proteins were overproduced and subjected to proteolysis by this metalloprotease to identify the multiple cleavage sites located on the N-terminal side of the phosphorylation site Ser^460. The results indisputably confirmed the presence of cleavage sites within the region between the α-helix domain （H14） and Ser^460 for this metalloprotease. Furthermore, the resulting C-terminally truncated LeACS2 isoforms were active enzymatically. Because this protease could produce LeACS2 isoforms in vitro similar to those detected in vivo, it is proposed that this metalloprotease may be involved in the proteolysis of LeACS2 in vivo.     

Ghrelin and NUCB2/nesfatin-1 are expressed in the same gastric cell and differentially correlated with body mass index in obese subjects

The orexigenic peptide ghrelin and the anorexigenic peptide nesfatin-1 are expressed by the same endocrine cell of the rat stomach, the X/A-like cell. However, data in humans are lacking, especially under conditions of obesity. We collected gastric tissue of obese patients undergoing sleeve gastrectomy and investigated the expression of nesfatin-1 and ghrelin in the gastric oxyntic mucosa by immunofluorescence. Nesfatin-1 immunoreactivity was detected in the human oxyntic mucosa in cells with an endocrine phenotype. A major portion of nesfatin-1 immunoreactive cells (78 %) co-localized with ghrelin indicating the occurrence in human X/A-like cells. In patients with very high body mass index (BMI 55–65 kg/m²), the number of nesfatin-1 immunoreactive cells/low-power field was significantly higher than in obese patients with lower BMI (40–50 kg/m², 118 ± 10 vs. 82 ± 11, p < 0.05). On the other hand, the number of ghrelin immunoreactive cells was significantly reduced in obese patients with higher compared to lower BMI (96 ± 12 vs. 204 ± 21, p < 0.01). Also the ghrelin-acylating enzyme ghrelin-O-acyltransferase decreased with increasing BMI. In conclusion, nesfatin-1 immunoreactivity is also co-localized with ghrelin in human gastric X/A-like cells giving rise to a dual role of this cell type with differential effects on stimulation and inhibition of appetite dependent on the peptide released. The expression of these two peptides is differentially regulated under obese conditions with an increase of nesfatin-1 and a decrease of ghrelin immunoreactivity with rising BMI pointing towards an adaptive change of expression that may counteract further body weight increase.     

Determination of the enantiomeric composition of (R*,S*)-1-ethylpropyl 2-methyl-3-hydroxypentanoate, the male-produced aggregation pheromone of Sitophilus granarius

The enantiomeric composition of sitophilate, the granary weevil [Sitophilus granarius (L.)] male-produced aggregation pheromone [(R^*,S^*)-1-ethylpropyl 2-methyl-3-hydroxypentanoate)], was determined by three methods: (1) bioassaying the synthetic (2S,3R) and (2R,3S) enantiomers of the active (R^*,S^*) diastereomer; (2) ¹H NMR spectroscopy of Mosher ester derivatives of the natural pheromone and synthetic (2S,3R)-and (2R,3S)-sitophilate; and (3) capillary GLC comparisons of the retention times of derivatized natural pheromone and the two synthetic enantiomers. The combined methods confirmed the (2S,3R) enantiomer as the active form of sitophilate. Male granary weevils were shown to produce >96% (2S,3R)-sitophilate. No significant attraction of S. granarius by the (2R,3S) enantiomer was observed. Rice and maize weevils [S. oryzae (L.) and S. zeamais Motschulsky] were not attracted by (2S,3R)-sitophilate. S. granarius L. est un déprédateur important des grains stockés. Le (R^*,S^*)-1-éthylpropyl 2-méthyl-3-hydroxypentanoate a été identifié en 1987 comme le principal composé du sitophilate, la phéromone mâle d'agrégation de S. granarius. La composition énantiométrique du sitophilate a été déterminée par 3 méthodes:

2型猪链球菌脑膜炎小鼠模型的构建及其转录组学分析

【背景】2型猪链球菌(Streptococcus suis serotype 2, S. suis 2)可感染宿主引起严重的脑膜炎,对养猪业和人类公共卫生安全构成重大威胁。【目的】构建S. suis 2感染小鼠脑膜炎模型,并对其脑组织进行转录组学分析,为揭示S.suis2感染宿主后引起脑膜炎的分子机制和发现潜在的治疗靶点提供理论依据。【方法】采用S. suis 2感染小鼠,并对其脑组织进行病理组织学分析确认构建脑膜炎小鼠后,对其脑组织进行转录组学分析,对比S.suis2感染和未感染小鼠的差异表达基因,并对差异表达基因进行基因本体论(geneontology,GO)功能、京都基因和基因组百科全书(Kyoto encyclopedia of genes and genomes, KEGG)通路富集和韦恩分析。【结果】脑病理组织学分析结果显示,S. suis 2感染的小鼠脑膜中有大量的炎症细胞浸润,并且血管周围出现“袖套”现象,并能从感染小鼠的组织器官中再分离出攻毒的S. suis 2菌株,结果证明构建了S. suis 2感染脑膜炎小鼠模型。转录组学分析结果表明,感染S.suis2与未感染的...     

Dominance Relationship between Two Self-Incompatible<Emphasis Type="Italic">Brassica campestris</Emphasis> Haplotypes in Response to CO<Subscript>2</Subscript> Gas

InBrassica, self-incompatibility (SI) can be overcome by CO₂ application, an effective method for obtaining numerous inbred lines for F, commercial seed. We previously reported two different S-alleles ofBrassica campestris, S⁷³³ and S⁷³⁴, with extremely different degrees of susceptibility to this gas. In the current study, we raised a cross-population between those two genetic lines, and analyzed their reaction level of self-incompatibility to CO₂ (RLSICO₂). Here, all 40 of our progeny from the F₁ cross-population were susceptible, maintaining high values of RLSICO₂. This suggests that the susceptible line, S⁷³⁴, is dominant to the insusceptible line, S⁷³³. We also generated an F₂ selfing-population of each crossed progeny, S⁷³³♀ S⁷³⁴♂ and S⁷³³♂ S⁷³⁴♀, to assess the RLSICO₂ of each individual. PCR-RFLP analysis was performed to determine the S-genotype of the F₂ population. The S⁷³⁴ allele segregated in a theoretical ratio of the dominant trait, and the RLSICO₂ was consistent with the dominance relationship. Therefore, we have now demonstrated that high RLSICO₂ in β.campestris is controlled by a dominant gene. Both authors contributed equally to this work