Context-dependent regulation of feeding behaviour by the insulin receptor,DAF-2, in <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis>

Insulin signalling plays a significant role in both developmental programmes and pathways modulating the neuronal signalling that controls adult behaviour. Here, we have investigated insulin signalling in food-associated behaviour in adult C. elegans by scoring locomotion and feeding on and off bacteria, the worm’s food. This analysis used mutants (daf-2, daf-18) of the insulin signalling pathway, and we provide evidence for an acute role for insulin signalling in the adult nervous system distinct from its impact on developmental programmes. Insulin receptor daf-2 mutants move slower than wild type both on and off food and showed impaired locomotory responses to food deprivation. This latter behaviour is manifest as a failure to instigate dispersal following prolonged food deprivation and suggests a role for insulin signalling in this adaptive response. Insulin receptor daf-2 mutants are also deficient in pharyngeal pumping on food and off food. Pharmacological analysis showed the pharynx of daf-2 is selectively compromised in its response to 5-HT compared to the excitatory neuropeptide FLP-17. By comparing the adaptive pharyngeal behaviour in intact worms and isolated pharyngeal preparations, we determined that an insulin-dependent signal extrinsic to the pharyngeal system is involved in feeding adaptation. Hence, we suggest that reactive insulin signalling modulates both locomotory foraging and pharyngeal pumping as the animal adapts to the absence of food. We discuss this in the context of insulin signalling directing a shift in the sensitivity of neurotransmitter systems to regulate the worm’s response to changes in food availability in the environment.     

Usefulness of the Non-conventional <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis> Model to Assess <Emphasis Type="Italic">Candida</Emphasis> Virulence

Invasive candidiasis is caused mainly by Candida albicans, but other Candida species have increasing etiologies. These species show different virulence and susceptibility levels to antifungal drugs. The aims of this study were to evaluate the usefulness of the non-conventional model Caenorhabditis elegans to assess the in vivo virulence of seven different Candida species and to compare the virulence in vivo with the in vitro production of proteinases and phospholipases, hemolytic activity and biofilm development capacity. One culture collection strain of each of seven Candida species (C. albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida metapsilosis, Candida orthopsilosis and Candida parapsilosis) was studied. A double mutant C. elegans AU37 strain (glp-4;sek-1) was infected with Candida by ingestion, and the analysis of nematode survival was performed in liquid medium every 24 h until 120 h. Candida establishes a persistent lethal infection in the C. elegans intestinal tract. C. albicans and C. krusei were the most pathogenic species, whereas C. dubliniensis infection showed the lowest mortality. C. albicans was the only species with phospholipase activity, was the greatest producer of aspartyl proteinase and had a higher hemolytic activity. C. albicans and C. krusei caused higher mortality than the rest of the Candida species studied in the C. elegans model of candidiasis.     

Phylogenetic assessment and taxonomic revision of <Emphasis Type="Italic">Mariannaea</Emphasis>

Four new species of Mariannaea were described in this paper, namely M. chlamydospora, M. cinerea, M. fusiformis, and M. lignicola. Mariannaea chlamydospora is characterized by its cream-colored, zonate colonies on PDA, smooth conidiophores, fusiform conidia, and abundant chlamydospores. Mariannaea cinerea forms grey colonies and ellipsoidal to subglobose conidia. Mariannaea fusiformis forms purple colonies and fusiform to subglobose conidia. Mariannaea lignicola has brown conidiophores and broad hyphae. The molecular phylogeny was inferred using ITS, LSU, and TUB-2 loci. The type species of Mariannaea (M. elegans) is epitypified. The variety M. elegans var. punicea is raised to species rank. Mariannaea clavispora is excluded from Mariannaea because of its cylindrical phialides, straight conidial chains and deviating phylogenetic affinity. Mariannaea nipponica did not fit well the generic concept of Mariannaea based on their morphological characters, and its generic placement remains uncertain. A key to the currently accepted 15 species of Mariannaea is provided.     

Cloning of <Emphasis Type="Italic">TaTPP-6AL1</Emphasis> associated with grain weight in bread wheat and development of functional marker

Trehalose 6-phosphate phosphatase (TPP) dephosphorylates trehalose 6-phosphate to trehalose, an important growth regulator, and is involved in starch accumulation and grain yield. In this study, wheat TPP homologs were isolated from chromosomes 6AL, 6BL, and 6DL, designated as TaTPP-6AL1, TaTPP-6BL1, and TaTPP-6DL1, respectively. Sequence alignment showed a single-nucleotide polymorphism (SNP) at TaTPP-6AL1 locus between cultivars with contrasting thousand grain weight (TGW), forming alleles TaTPP-6AL1a and TaTPP-6AL1b, respectively. A cleaved amplified polymorphic sequence (CAPS) marker, TaTPP-6AL1-CAPS, was developed to differentiate the two alleles. TaTPP-6AL1 was mapped within the interval of IWB65749 and IWB60449 in a recombinant inbred line (RIL) population derived from Zhou8425B/Chinese Spring using the wheat 90K SNP assay. A QTL for TGW identified in the interval explained 12.1–19.1% of the phenotypic variance across five environments. Association analysis on 141 Chinese wheat cultivars also indicated a significant correlation of TaTPP-6AL1 with TGW. In conclusion, TaTPP-6AL1 and its functional marker are valuable to improve grain yield in wheat breeding.     

The Differentiation of Skin Mesenchymal Stem Cells Towards a Schwann Cell Phenotype: Impact of Sigma-1 Receptor Activation

Neural crest stem cells (NCSCs) are the source of mature Schwann cells in the peripheral nervous system (PNS). The NCSC population resides in the bulge of hair follicles and in the dermis. Recently, it was shown that 2–3% of the human dermis mesenchymal stem cell (MSC) population expresses the NCSC marker CD271, thus enabling the use of skin MSCs for studying Schwann cell differentiation in vitro. The aims of this study were to establish a protocol for human skin MSC differentiation towards Schwann cell-like cells (SC-lcs) and to analyse the expression of sigma-1 receptor (S1R) in SC-lcs. The impact of S1R ligands, namely the selective agonist PRE-084, the positive allosteric modulator E1R and the selective antagonist NE-100, on Schwann cell differentiation was assessed. The expression of the neuron-specific genes Tubulin-βIII and Integrin-6α, the Schwann cell-specific gene S100b, MBP and the NCSC-specific genes p75NTR, Sox10, Notch1, Integrin-4α, Ap2α and Pax6 was analysed in MSCs and SC-lcs by real-time RT-PCR. BDNF secretion was evaluated by ELISA. The effect of S1R ligands on SC-lc differentiation was measured using BDNF ELISA and MBP flow cytometry. After MSC differentiation, NCSC markers p75NTR and Integrin-4α were downregulated 3.5-fold and 2-fold, respectively. To the contrary, MBP and S100b were significantly upregulated in SC-lcs. S1R ligands showed a tendency to increase the secretion of BDNF by the SC-lc population. PRE-084 and E1R increased MBP expression in the SC-lc population, whereas 3 μM NE-100 inhibited MBP expression in SC-lcs. In conclusion, our data demonstrate that S1R plays an important role in skin MSC differentiation towards myelinating Schwann cells.     

Nematicidal metabolites from <Emphasis Type="Italic">Gliocladium roseum</Emphasis> YMF1.00133

A strain of the fungus Gliocladium roseum YMF1.00133 was found to secrete nematicidal metabolites against nematodes Panagrellus redivivus, Caenothabditis elegans and Bursaphelenchus xylophilus in experiments searching for nematicidal fungi. Through bioassay-guided fractionations, a unique trioxopiperazine alkaloid, gliocladin C (compound 1), and an alkylane resorcinol, 5-n-heneicosylresorcinol (compound 2) were obtained from the methanol extract of the fungus and determined by single-crystal X-ray analysis and spectroscopic data. In vitro immersion experiments showed that the ED₅₀ values of compounds 1 and 2 after 24 h incubation were 15 and 30 μg/mL against C. elegans, 50 and 80 μg/mL against P. redivivus, and 200 and 180 μg/mL against B. xylophilus, respectively. The X-ray diffraction data of compound 1 and the nematicidal activity of compounds 1 and 2 were reported for the first time.     

Effect of gamma radiation on the expression of mRNA growth factors in glycerol cryopreserved human amniotic membrane

Human amniotic membrane (HAM) due to its high biocompatibility, low immunogenicity, anti-microbial, anti-viral properties as well as the presence of growth factors has been used in various clinical applications. The growth factors play an important role in wound healing. The current study aimed to explore the effect of 15 kGy gamma radiation dose on selected growth factors and receptors mRNA present in HAM. Eight growth factors, namely, EGF, HGF, KGF, TGF-α, TGF-β1, TGF-β2, TGF-β3 and bFGF and two growth factor receptors, HGFR and KGFR were evaluated in this study. The total RNA was extracted and converted to complimentary DNA using commercial kits. Subsequently, the mRNA expressions of these growth factors were evaluated using real-time PCR and the results were statistically analyzed using REST-MCS software. This study confirmed the presence of these mRNA growth factors and receptors in fresh, glycerol cryopreserved and irradiated glycerol cryopreserved HAM. In glycerol cryopreserved HAM, the results showed up-regulation of HGF and bFGF and down-regulation of EGF, HGFR, KGF, KGFR, TGF-α, TGF-β1, TGF-β2 and TGF-β3 relative to the fresh HAM which acted as the control, whereas in irradiated glycerol cryopreserved HAM, the results showed up-regulation of EGF, HGF, KGF, KGFR, TGF-β1, TGF-β2 and TGF-β3 and down-regulation of HGFR, TGF-α and bFGF relative to the glycerol cryopreserved HAM which acted as the control. However, these mRNA expressions did not show any statistical significant difference compared to the control groups. This study concluded that a dose of 15 kGy of gamma radiation did not affect the mRNA expression for the growth factors’ and receptors’ in the glycerol cryopreserved HAM.     

Genome-wide identification and expression profiling analysis of brassinolide signal transduction genes regulating apple tree architecture

Brassinolide (BR) is crucial for regulating plant architecture. Apple dwarfing rootstocks are used to control apple tree size. However, information regarding the effects of BR on apple trees is limited. In addition, the molecular mechanism underlying the dwarfing of apple rootstocks is poorly understood. To elucidate the role of BR signal transduction genes in controlling apple tree architecture, five BR receptor kinase 1 (BRI1), nine BR-signaling kinase 1 (BSK1), two BRI1 KINASE INHIBITOR 1 (BKI1), and seven BR-insensitive 2 (BIN2) genes were analyzed. Bioinformatic analyses revealed that gene duplication events likely contributed to the expansion and evolution of the identified genes. Nine homologs between apple and Arabidopsis thaliana were also identified, and their expression patterns in different tissues were characterized. Exogenous BR treatments increased the primary shoot length and altered the expression of BR signal transduction genes (MdBRI1-5, MdBSK3-8, MdBKI1–2, MdBIN1–4, and MdBIN6/7). The scion of Fuji/Malling 9 (M.9) trees exhibited inhibited growth compared with that of Fuji/Fuji trees. The Fuji/M.9 trees had lower levels of the positive regulators of BR signaling (MdBRI1-5,MdBSK1, MdBSK4/7, and MdBSK6) and higher levels of the negative regulators (MdBIN5-7) compared with the Fuji/Fuji trees. Thus, the above-mentioned genes may help to regulate apple tree size in response to BR. In addition, MdBRI1–5, MdBSK1, MdBSK4/7, MdBSK6, and MdBIN5–7 have important roles in different grafting combinations. Our results may provide the basis for future analyses of BR signal transduction genes regarding their potential involvement in the regulation of plant architecture.     

Bone marrow mesenchymal stem cell transplantation improves radiation-induced heart injury through DNA damage repair in rat model

Radiotherapy is an effective form of therapy for most thoracic malignant tumors. However, myocardial injury resulting from the high doses of radiation is a severe complication. Here we aimed to study the possibility of reducing radiation-induced myocardial injury with mesenchymal stem cell (MSC) transplantation. We used MSCs extracted from bone marrow (BMSCs) to transplant via the tail vein into a radiation-induced heart injury (RIHI) rat model. The rats were divided into six groups: a Sham group, an IRR (irradiation) group, and four IRR + BMSCs transplantation groups obtained at different time points. After irradiation, BMSC transplantation significantly enhanced the cardiac function in rats. By analyzing the expression of PPAR-α, PPAR-γ, TGF-β, IL-6, and IL-8, we found that BMSC transplantation alleviated radiation-induced myocardial fibrosis and decreased the inflammatory reaction. Furthermore, we found that expression of γ-H2AX, XRCC4, DNA ligase4, and TP53BP1, which are associated with DNA repair, was up-regulated, along with increased secretion of growth factors SDF-1, CXCR4, VEGF, and IGF in rat myocardium in the IRR + BMSCs transplantation groups compared with the IRR group. Thus, BMSC transplantation has the potential to improve RIHI via DNA repair and be a new therapeutic approach for patients with myocardial injury.     

Suppression of Settlement of Larvae of Fouling Organism by Water-Soluble Substances from Epibiotic Bacteria

Twenty-nine bacterial strains were isolated from the surface of the green alga Ulva reticulata, the soft coral Dendronephthya sp., and the sponge Haliclona sp. The bacterial species Vibrio alginolyticus, Vibrio sp. 4, an unidentified α-Proteobacterium, Vibrio sp. 7, Pseudoalteromonas sp. 2, and Pseudoalteromonas sp. 4 were found to suppress the larval settlement of the polychaete Hydroides elegans (Haswell, 1883) and the bryozoan Bugula neritina (Linnaeus, 1758). Aqueous extracts of five bacteria (all those named above except Pseudoalteromonas sp. 2) prevented larval settlement. Bacteria V. alginolyticus, Vibrio sp. 4, and an unidentified α-Proteobacterium were first discovered to produce high-molecular substances (>100 kDa) preventing larval settlement. Their activity was inhibited by amylase treatment, while trypsin and papain did not influence their activity. The data obtained proved that bacteria from the surface of the number of marine organisms excrete water-soluble sacchariferous compounds preventing larval settlement.     

Pancreatic lipase inhibitory activity of monogalactosyldiacylglycerols isolated from the freshwater microalga <Emphasis Type="Italic">Chlorella sorokiniana</Emphasis>

Chemical investigation of the freshwater microalga Chlorella sorokiniana led to the isolation of a monogalactosyldiacylglycerol (MGDG)-rich fraction possessing dose-dependent inhibitory activity against pancreatic lipase activity. The MGDG-rich fraction contains 12 MGDGs identified by LC/HRMS analysis. Among them, three MGDGs were new compounds, namely, (2S)-1-O-(7Z,10Z-hexadecadienoyl)-2-O-(7Z,10Z,13Z-hexadecatrienoyl)-3-O-β-D-galactopyranosylglycerol (1), (2S)-1-O-linoleoyl-2-O-(7Z,10Z-hexadecadienoyl)-3-O-β-D-galactopyranosylglycerol (6), and (2S)-1-O-oleoyl-2-O-(7Z,10Z-hexadecadienoyl)-3-O-β-D-galactopyranosylglycerol (8). The major galactolipids were isolated by semipreparative HPLC and tested for their effect toward pancreatic lipase inhibitory activity. All the tested MGDGs showed significant reduction of pancreatic lipase activity indicating possible beneficial use for management of lipase-related disorders such as obesity.     

NtRING1, putative RING-finger E3 ligase protein,is a positive regulator of the early stages of elicitin-induced HR in tobacco

Key message

NtRING1 is a RING-finger protein with a putative E3 ligase activity. NtRING1 regulates HR establishment against different pathogens. Loss-/gain-of-function of NtRING1 altered early stages of HR phenotype establishment.

Abstract

Plant defence responses against pathogens often involve the restriction of pathogens by inducing a hypersensitive response (HR). cDNA clones DD11-39, DD38-11 and DD34-26 were previously obtained from a differential screen aimed at characterising tobacco genes with an elicitin-induced HR-specific pattern of expression. Our precedent observations suggested that DD11-39, DD38-11 and DD34-26 might play roles in the HR establishment. Only for DD11-39 a full-length cDNA sequence was obtained and the corresponding protein encoded for a type-HC RING-finger/putative E3 ligase protein which we termed NtRING1. The expression of NtRING1 was upregulated upon HR induction by elicitin, Ralstonia solanacearum, or tobacco mosaic virus (TMV) in tobacco. Silencing of NtRING1 remarkably delayed the establishment of elicitin-induced HR in tobacco as well as the expression of different early induction genes in tissues undergoing HR. Accordingly, transient overexpression of NtRING1 accelerated the HR launching upon elicitin treatment. Taking together, our data suggests that NtRING1 plays a functional role in the early establishment of HR.

     

Steroid Compounds from Far Eastern Starfishes <Emphasis Type="Italic">Henricia aspera</Emphasis> and <Emphasis Type="Italic">H. tumida</Emphasis>

Six new natural compounds were isolated from two Far Eastern starfish species, Henricia aspera and H. tumida, collected in the Sea of Okhotsk. Two new glycosylated steroid polyols were obtained from H. aspera: asperoside A and asperoside B, which were shown to be (20R,24R, 25S)-3-O-(2,3-di-O-methyl-β -D-xylopyranosyl)-24-methyl-5α-cholest-4-ene-3β, 6β,8,15α,16β,26-hexaol and (20R, 24R,25S,22E)-3-O-(2,4-di-O-methyl-β-D-xylopyranosyl)-24-methyl-5α-cholest-22-ene-3β,4β,6β,8,15α,26-hexaol, respectively. Two other glycosylated polyols, tumidoside A, with the structure elucidated as (20R, 22E)-3-O-(2,4-di-O-methyl-β -D-xylopyranosyl)-26,27-dinor-24-methyl-5α-cholest-22-ene-3β,4β,6β,8,15α,25-hexaol, and tumidoside B, whose structure was elucidated as (20R,24S)-3-O-(2,3-di-O-methyl-β-D-xylopyranosyl)-5α-cholestan-3β,4β,6β,8,15α,24-hexaol, were isolated from the two starfish species. (20R, 24S)-5α-Cholestan-3β,6β,15α,24-tetraol and (20R, 24S)-5α-cholestan-3β,6β,8,15α,24-pentaol were identified only in H. tumida. The known monoglycosides henricioside H1 and laeviuscolosides H and G were also identified in both species.     

Fine mapping of a male sterility gene <Emphasis Type="Italic">ms</Emphasis>-<Emphasis Type="Italic">3</Emphasis> in a novel cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.) mutant

Key message

The cucumber male sterility gene ms - 3 was fine mapped in a 76 kb region harboring an MMD1 -like gene Csa3M006660 that may be responsible for the male sterile in cucumber.

Abstract

A cucumber (Cucumis sativus L.) male sterile mutant (ms-3) in an advanced-generation inbred line was identified, and genetic analysis revealed that the male sterility trait was controlled by a recessive nuclear gene, ms-3, which was stably inherited. Histological studies suggested that the main cause of the male sterility was defective microsporogenesis, resulting in no tetrad or microspores being formed. Bulked segregant analysis (BSA) and genotyping of an F₂ population of 2553 individuals were employed used to fine map ms-3, which was delimited to a 76 Kb region. In this region, a single non-synonymous SNP was found in the Csa3M006660 gene locus, which was predicted to result in an amino acid change. Quantitative RT-PCR analysis of Csa3M006660 was consistent with the fact that it plays a role in the early development of cucumber pollen. The protein encoded by Csa3M006660 is predicted to be homeodomain (PHD) finger protein, and the high degree of sequence conservation with homologs from a range of plant species further suggested the importance of the ms-3 non-synonymous mutation. The data presented here provide support for Csa3M006660 as the most likely candidate gene for Ms-3.