Displaying publications 1 - 20 of 23764 in total

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  1. Nhu NTK, Phan MD, Peters KM, Lo AW, Forde BM, Min Chong T, et al.
    mBio, 2018 08 21;9(4).
    PMID: 30131362 DOI: 10.1128/mBio.01462-18
    Curli are bacterial surface-associated amyloid fibers that bind to the dye Congo red (CR) and facilitate uropathogenic Escherichia coli (UPEC) biofilm formation and protection against host innate defenses. Here we sequenced the genome of the curli-producing UPEC pyelonephritis strain MS7163 and showed it belongs to the highly virulent O45:K1:H7 neonatal meningitis-associated clone. MS7163 produced curli at human physiological temperature, and this correlated with biofilm growth, resistance of sessile cells to the human cationic peptide cathelicidin, and enhanced colonization of the mouse bladder. We devised a forward genetic screen using CR staining as a proxy for curli production and identified 41 genes that were required for optimal CR binding, of which 19 genes were essential for curli synthesis. Ten of these genes were novel or poorly characterized with respect to curli synthesis and included genes involved in purine de novo biosynthesis, a regulator that controls the Rcs phosphorelay system, and a novel repressor of curli production (referred to as rcpA). The involvement of these genes in curli production was confirmed by the construction of defined mutants and their complementation. The mutants did not express the curli major subunit CsgA and failed to produce curli based on CR binding. Mutation of purF (the first gene in the purine biosynthesis pathway) and rcpA also led to attenuated colonization of the mouse bladder. Overall, this work has provided new insight into the regulation of curli and the role of these amyloid fibers in UPEC biofilm formation and pathogenesis.IMPORTANCE Uropathogenic Escherichia coli (UPEC) strains are the most common cause of urinary tract infection, a disease increasingly associated with escalating antibiotic resistance. UPEC strains possess multiple surface-associated factors that enable their colonization of the urinary tract, including fimbriae, curli, and autotransporters. Curli are extracellular amyloid fibers that enhance UPEC virulence and promote biofilm formation. Here we examined the function and regulation of curli in a UPEC pyelonephritis strain belonging to the highly virulent O45:K1:H7 neonatal meningitis-associated clone. Curli expression at human physiological temperature led to increased biofilm formation, resistance of sessile cells to the human cationic peptide LL-37, and enhanced bladder colonization. Using a comprehensive genetic screen, we identified multiple genes involved in curli production, including several that were novel or poorly characterized with respect to curli synthesis. In total, this study demonstrates an important role for curli as a UPEC virulence factor that promotes biofilm formation, resistance, and pathogenesis.
    Matched MeSH terms: Female
  2. Mustafar F, Harvey MA, Khani A, Arató J, Rainer G
    eNeuro, 2018 07 11;5(4).
    PMID: 30073190 DOI: 10.1523/ENEURO.0167-18.2018
    Our understanding of the neurobiological underpinnings of learning and behavior relies on the use of invasive techniques, which necessitate the use of animal models. However, when different species learn the same task, to what degree are they actually producing the same behavior and engaging homologous neural circuitry? This question has received virtually no recent attention, even as the most powerful new methodologies for measuring and perturbing the nervous system have become increasingly dependent on the use of murine species. Here, we test humans, rats, monkeys, and an evolutionarily intermediate species, tree shrews, on a three alternative, forced choice, visual contrast discrimination task. As anticipated, learning rate, peak performance, and transfer across contrasts was lower in the rat compared to the other species. More interestingly, rats exhibited two major behavioral peculiarities: while monkeys and tree shrews based their choices largely on visual information, rats tended to base their choices on past reward history. Furthermore, as the task became more difficult, rats largely disengaged from the visual stimulus, reverting to innate spatial predispositions in order to collect rewards near chance probability. Our findings highlight the limitation of muridae as models for translational research, at least in the area of visually based decision making.
    Matched MeSH terms: Female
  3. Loh SY, Jahans-Price T, Greenwood MP, Greenwood M, Hoe SZ, Konopacka A, et al.
    eNeuro, 2017 12 21;4(6).
    PMID: 29279858 DOI: 10.1523/ENEURO.0243-17.2017
    The supraoptic nucleus (SON) is a group of neurons in the hypothalamus responsible for the synthesis and secretion of the peptide hormones vasopressin and oxytocin. Following physiological cues, such as dehydration, salt-loading and lactation, the SON undergoes a function related plasticity that we have previously described in the rat at the transcriptome level. Using the unsupervised graphical lasso (Glasso) algorithm, we reconstructed a putative network from 500 plastic SON genes in which genes are the nodes and the edges are the inferred interactions. The most active nodal gene identified within the network was Caprin2. Caprin2 encodes an RNA-binding protein that we have previously shown to be vital for the functioning of osmoregulatory neuroendocrine neurons in the SON of the rat hypothalamus. To test the validity of the Glasso network, we either overexpressed or knocked down Caprin2 transcripts in differentiated rat pheochromocytoma PC12 cells and showed that these manipulations had significant opposite effects on the levels of putative target mRNAs. These studies suggest that the predicative power of the Glasso algorithm within an in vivo system is accurate, and identifies biological targets that may be important to the functional plasticity of the SON.
    Matched MeSH terms: Female
  4. Bhattacharya P, Ellegård R, Khalid M, Svanberg C, Govender M, Keita ÅV, et al.
    Elife, 2020 09 02;9.
    PMID: 32876566 DOI: 10.7554/eLife.57869
    HIV transmission via genital and colorectal mucosa are the most common routes of dissemination. Here, we explored the effects of free and complement-opsonized HIV on colorectal tissue. Initially, there was higher antiviral responses in the free HIV compared to complement-opsonized virus. The mucosal transcriptional response at 24 hr revealed the involvement of activated T cells, which was mirrored in cellular responses observed at 96 hr in isolated mucosal T cells. Further, HIV exposure led to skewing of T cell phenotypes predominantly to inflammatory CD4+ T cells, that is Th17 and Th1Th17 subsets. Of note, HIV exposure created an environment that altered the CD8+ T cell phenotype, for example expression of regulatory factors, especially when the virions were opsonized with complement factors. Our findings suggest that HIV-opsonization alters the activation and signaling pathways in the colorectal mucosa, which promotes viral establishment by creating an environment that stimulates mucosal T cell activation and inflammatory Th cells.
    Matched MeSH terms: Female
  5. Fornace KM, Alexander N, Abidin TR, Brock PM, Chua TH, Vythilingam I, et al.
    Elife, 2019 10 22;8.
    PMID: 31638575 DOI: 10.7554/eLife.47602
    Human movement into insect vector and wildlife reservoir habitats determines zoonotic disease risks; however, few data are available to quantify the impact of land use on pathogen transmission. Here, we utilise GPS tracking devices and novel applications of ecological methods to develop fine-scale models of human space use relative to land cover to assess exposure to the zoonotic malaria Plasmodium knowlesi in Malaysian Borneo. Combining data with spatially explicit models of mosquito biting rates, we demonstrate the role of individual heterogeneities in local space use in disease exposure. At a community level, our data indicate that areas close to both secondary forest and houses have the highest probability of human P. knowlesi exposure, providing quantitative evidence for the importance of ecotones. Despite higher biting rates in forests, incorporating human movement and space use into exposure estimates illustrates the importance of intensified interactions between pathogens, insect vectors and people around habitat edges.
    Matched MeSH terms: Female
  6. Zhou L, Wang P, Zhang J, Heng BC, Tong GQ
    Zygote, 2016 Feb;24(1):89-97.
    PMID: 25672483 DOI: 10.1017/S0967199414000768
    ING2 (inhibitor of growth protein-2) is a member of the ING-gene family and participates in diverse cellular processes involving tumor suppression, DNA repair, cell cycle regulation, and cellular senescence. As a subunit of the Sin3 histone deacetylase complex co-repressor complex, ING2 binds to H3K4me3 to regulate chromatin modification and gene expression. Additionally, ING2 recruits histone methyltransferase (HMT) activity for gene repression, which is independent of the HDAC class I or II pathway. However, the physiological function of ING2 in mouse preimplantation embryo development has not yet been characterized previously. The expression, localization and function of ING2 during preimplantation development were investigated in this study. We showed increasing expression of ING2 within the nucleus from the 4-cell embryo stage onwards; and that down-regulation of ING2 expression by endoribonuclease-prepared small interfering RNA (esiRNA) microinjection results in developmental arrest during the morula to blastocyst transition. Embryonic cells microinjected with ING2-specific esiRNA exhibited decreased blastulation rate compared to the negative control. Further investigation of the underlying mechanism indicated that down-regulation of ING2 significantly increased expression of p21, whilst decreasing expression of HDAC1. These results suggest that ING2 may play a crucial role in the process of preimplantation embryo development through chromatin regulation.
    Matched MeSH terms: Female
  7. Okomoda VT, Koh ICC, Shahreza MS
    Zygote, 2017 Aug;25(4):443-452.
    PMID: 28635581 DOI: 10.1017/S0967199417000259
    Breeding and larval performance of novel hybrids from reciprocal crosses of Asian catfish Pangasianodon hypophthalmus (Sauvage, 1878) and African catfish Clarias gariepinus (Burchell, 1822) were investigated in this study. Spawning was by hormonal injection of brood fish, artificial fertilization, and incubation in triplicate aquarium tanks (0.5 × 0.5 × 0.5 m3) with continuous aeration. Reciprocal crosses (♀C. gariepinus × ♂P. hypophthalmus and ♀P. hypophthalmus × ♂C. gariepinus) had lower hatchability (≤50%) than their pure siblings (≥75%). Fish from all crosses survived until the juvenile stage but survival at 35 days post hatching (dph) was higher for pure C. gariepinus sib. ♀C. gariepinus × ♂P. hypophthalmus was observed to be less resistant to degradation of water quality than the other crosses, however it had higher body weight compared with the other crosses that showed similar performance. Morphological comparison of surviving juvenile at 35 dph, showed that all ♀P. hypophthalmus × ♂C. gariepinus and 13% of the ♀C. gariepinus × ♂P. hypophthalmus exhibited the very same morphology as that of their maternal parent species, while the other portion of the ♀C. gariepinus × ♂P. hypophthalmus cross exhibited morphological traits that were intermediate between those of both parent species. This study been the first successful attempt to hybridize both species and therefore, laid the groundwork for further studies on the aquaculture potentials of the novel hybrids.
    Matched MeSH terms: Female
  8. Hassan A, Okomoda VT, Sanusi FAB
    Zygote, 2018 Oct;26(5):343-349.
    PMID: 30296962 DOI: 10.1017/S0967199418000187
    SummaryThis study investigated the breeding parameters and embryogenic development of diploid and heat shock-induced triploid eggs of Anabas testudineus (Bloch, 1792). To this effect, broodstocks of A. testudineus were induced to spawn using the Ovaprim® hormone. After fertilization, the eggs were divided into two groups and one portion heat shocked at 41°C (for 3 min), at approximately 4 min after fertilization. Results of fertilization, hatchability, as well as the sequence and timing of embryogenic development were collated from three breeding trials. Fertilization percentages were similar in both treatments (≈90%) while hatchability was higher in the diploid eggs (79.56%) than the triploid induced eggs (50.04%). Both treatments had the same sequence of embryogenetic stages; however, the timing of development was significantly delayed in the triploids (i.e. beyond the 2-cell stages) as compared with the observations in the control group (diploid eggs). Consequently, hatching time was 5 h faster in the diploid eggs [i.e. 18 hours post fertilization (hpf)] compared with the triploid induced eggs (23 hpf). The most critical stage of embryonic development in which mass mortality occurred in the different treatments was the somite stage. The status of triploid hatchlings was affirmed using erythrocyte morphology in 2-month-old fingerlings.
    Matched MeSH terms: Female
  9. Tan MK, Ingrisch S, Kamaruddin KN
    Zootaxa, 2015 Dec 11;4057(3):437-43.
    PMID: 26701492 DOI: 10.11646/zootaxa.4057.3.9
    The taxonomy of poorly known Mesagraecia Ingrisch, 1998 is reviewed. A new species of Mesagraecia spine-headed katydid (Conocephalinae: Agraeciini) is described from Bukit Larut, Perak, Peninsular Malaysia: Mesagraecia larutensis sp. n. A key to species is also presented.
    Matched MeSH terms: Female
  10. Lackner T
    Zootaxa, 2015;4044(2):289-300.
    PMID: 26624713 DOI: 10.11646/zootaxa.4044.2.6
    The genus Procoryphaeus Mazur, 1984 is revised herein. It contains three species: Procoryphaeus violaceus (Lewis, 1905) from Thailand: Tenasserim Mountains; Malaysia: Borneo: Sabah; Indonesia: Java, Sumatra and Papua, Procoryphaeus pilosus (Lewis, 1893) from Tanimbar Island, Indonesia and Procoryphaeus wallacei (Marseul, 1864) from Indonesia: Papua. All type specimens are figured, and male genitalia of P. violaceus are drawn. Lectotypes of Pachycraerus (Coryphaeus) wallacei Marseul, 1864, Coryphaeus violaceus Lewis, 1905 and Coryphaeus pilosus Lewis, 1893 are designated. The exact identities of P. violaceus and P. wallacei species remain unclear since they are morphologically very similar and both respective type specimens are females. A key to species is given.
    Matched MeSH terms: Female
  11. Orr AG, Dow RA
    Zootaxa, 2015;4040(3):384-92.
    PMID: 26624673 DOI: 10.11646/zootaxa.4040.3.9
    The final stadium larva of Onychargia atrocyana Selys, 1865, is described and illustrated based on two female specimens collected at Gunung Mulu National Park, Sarawak, East Malaysia. The larvae were identified by matching the mitochondrial marker COI with that of known adult specimens from Gunung Mulu, Bintulu and Kuching in Sarawak and from Pahang state in West Malaysia. The specimens presented close matches with all adults in this gene. As O. atrocyana is a taxonomically isolated species with no close congeners in Borneo the determination is beyond doubt. O. atrocyana is the only member of the Onychargiinae for which the larva is known. It is compared with the known larvae of other platycnemidid subfamilies, and the possible significance of larval morphology in higher classification of the group is discussed.
    Matched MeSH terms: Female
  12. Ng YF
    Zootaxa, 2015;4032(2):246-50.
    PMID: 26624359 DOI: 10.11646/zootaxa.4032.2.13
    Amalothrips noorazlani sp. n. is described from Malaysia based on both sexes, and a key is provided to the species of this genus. This is the first record of Amalothrips species outside India, and the first description of a male Amalothrips. The male has a pair of drepanae, the tergal posteromargin bears a toothed craspedum, but there are no sternal pore plates.
    Matched MeSH terms: Female
  13. Kontschán J, Kiss B
    Zootaxa, 2015;4021(4):515-28.
    PMID: 26624150 DOI: 10.11646/zootaxa.4021.4.2
    Five new species of the family Rotundabaloghiidae are described from Indonesia and Malaysia. Angulobaloghia pedunculata sp. nov. differs from the other Angulobaloghia Hirschmann, 1979 species in the shape of the genital shield of the female. Rotundabaloghia (Rotundabaloghia) wangi sp. nov. has one pair of short and pilose setae (V8) on the ventral idiosoma, which is unique in the subgenus Rotundabaloghia (Rotundabaloghia) Hirschmann, 1975. Rotundabaloghia (Circobaloghia) javaensis sp. nov. has a small triangular anterior process on genital shield of female, which has not been detected previously in South-East Asian members of this subgenus. The long and thick ventral seta (V4) in Depressorotunda (Depressorotunda) robusta sp. nov. is a character state so far unknown in the subgenus Depressorotunda (Depressorotunda) Kontschán, 2010. Depressorotunda (Depressorotunda) hirca sp. nov. has two apically serrate anterior branches on the margin of the female genital shield.
    Matched MeSH terms: Female; Genitalia, Female
  14. Łagowska B, Martin JH, Hodgson CJ
    Zootaxa, 2015;4006(1):128-42.
    PMID: 26623761 DOI: 10.11646/zootaxa.4006.1.6
    All life stages (adult female and male, first-instar nymph, second-instar male and female nymphs, and prepupa and pupa) of a new species of Asterolecaniidae, Bambusaspis transversa Lagowska & Martin sp. n., from bamboo in Malaysia, are described and illustrated. The adult female and first-instar nymphs are compared with those Bambusaspis species considered to be closest to the new species.
    Matched MeSH terms: Female
  15. Kondorosy E, Fábics A
    Zootaxa, 2015 Jan 05;3904(1):95-104.
    PMID: 25660773 DOI: 10.11646/zootaxa.3904.1.5
    The previously known distribution area of the genus Grossander Slater, 1976 (Hemiptera, Heteroptera, Rhyparochromidae, Drymini) is broadened with the description of two new species: Grossander papuanus sp. nov. (New Guinea) and Grossander eylesi sp. nov. (Burma, Laos, Thailand, Malaysia and Indonesia). Grossander (Oculoander) subgen. nov. is created for these new taxa. Drawings of habitus and male genitalia are presented. Keys to the subgenera of Grossander, and to the species of the new subgenus are provided.
    Matched MeSH terms: Female
  16. Ya'cob Z, Takaoka H, Sofian-Azirun M
    Zootaxa, 2014;3881(3):228-36.
    PMID: 25543632 DOI: 10.11646/zootaxa.3881.3.2
    Simulium (Nevermannia) ledangense sp. nov. is described from females, males, pupae and mature larvae from Peninsular Malaysia. This new species is assigned to the Simulium feuerborni species-group of the subgenus Nevermannia, and is characterized by the pupa having a very long stalk of the ventral paired gill filaments, which is almost five times longer than the interspiracular trunk and female tergites of segments 2 and 5 to 7 shiny. Taxonomic notes are given to distinguish this new species from three known species of the S. feuerborni species-group from Malaysia.
    Matched MeSH terms: Female
  17. Chan KO, Grismer LL, Brown RM
    Zootaxa, 2014;3900(4):569-80.
    PMID: 25543757 DOI: 10.11646/zootaxa.3900.4.7
    A new species of Narrow-mouthed frog of the genus Kaloula is described from northern Peninsular Malaysia. Kaloula latidisca sp. nov. is genetically and morphologically most similar to K. baleata and K. indochinensis but differs from those and other congeners by the unique combination of the following characters: (1) adult males SVL 49.2-56.2 mm (x̅=53.5 ± 3.0; N=4); (2) finger tips expanded into large, transversely expanded discs (disc width 2.8-3.1 mm, x̅=3.0 ± 0.1); (3) inner metatarsal tubercle large, oval, distinctly raised, slightly shorter than first toe; (4) three subarticular tubercles on fourth toe; (5) toe webbing formula: I 1-2 II 1-3 III 2-3.5 IV 4-2 V; and (6) yellow to orange irregularly shaped patch on the axillary, inguinal and posterior region of thigh.
    Matched MeSH terms: Female
  18. Ruta R, Kiałka A, Yoshitomi H
    Zootaxa, 2014;3902:1-62.
    PMID: 25543840 DOI: 10.11646/zootaxa.3902.1.1
    New species of the Scirtes flavoguttatus species-group are described from SE Asia. Altogether 34 species are newly described, including Scirtes beccus sp. nov. (Malaysia), S. bocakorum sp. nov. (Indonesia), S. crockerensis sp. nov. (Malaysia), S. decorus sp. nov. (Malaysia), S. dumogensis sp. nov. (Indonesia), S. gunongmulensis sp. nov. (Malaysia), S. ishikawai sp. nov. (Vietnam), S. kinabalensis sp. nov. (Malaysia), S. kundasangensis sp. nov. (Malaysia), S. lambriensis sp. nov. (Indonesia), S. leuserensis sp. nov. (Indonesia), S. luteus sp. nov. (Malaysia), S. malaisei sp. nov. (Myanmar), S. melinauensis sp. nov. (Malaysia), S. noonadan sp. nov. (Philippines), S. pallicolor sp. nov. (Malaysia), S. penampangensis sp. nov. (Malaysia), S. phoupanensis sp. nov. (Laos), S. prodigiosus sp. nov. (Malaysia), S. punctatus sp. nov. (Philippines), S. quasibalehensis sp. nov. (Malaysia), S. ranauensis sp. nov. (Malaysia), S. sarawakensis sp. nov. (Malaysia), S. seblatensis sp. nov. (Indonesia), S. sibayensis sp. nov. (Indonesia), S. sibolangitensis sp. nov. (Indonesia), S. sulawesicus sp. nov. (Indonesia), S. sulcigeroides sp. nov. (Malaysia), S. talinisensis sp. nov. (Philippines), S. ulukimanisensis sp. nov. (Malaysia), S. velutinus sp. nov. (Malaysia), S. vietnamicus sp. nov. (Vietnam), S. wallacei sp. nov. (Indonesia), S. yangsinensis sp. nov. (Vietnam). New localities of six species are provided. An updated identification key, checklist and a summary of distributional data are included. Probability of the occurrence of the Scirtes flavoguttatus species-group was evaluated with an analysis in MaxEnt software. It is highly plausible that members of the group occur in most mountainous rainforests of SE Asia. 
    Matched MeSH terms: Female
  19. Rosli N, Leduc D, Probert PK
    Zootaxa, 2014;3900(4):505-25.
    PMID: 25543753 DOI: 10.11646/zootaxa.3900.4.3
    We describe two new species and provide one new species record of the family Comesomatidae from a submarine canyon habitat on the Southern Hikurangi margin, New Zealand. Vasostoma hexodontium n. sp. is characterized by having an amphideal fovea with three turns, buccal cavity with six teeth and gubernaculum with long and straight caudal apophyses. Sabatieria dispunctata n. sp. is characterized by the absence of cuticle punctations, large amphideal fovea with 4.5 turns, pharynx with posterior bulb, absence of pre-cloacal supplements, strongly arcuate and cuticularized spicules, simple gubernaculum with short caudal apophyses, and vulva opening directed posteriorly. Laimella subterminata Chen & Vincx, 2000, which was originally described from the Beagle Channel and the Magellan Strait (Chile), is recorded from the Southwest Pacific for the first time. 
    Matched MeSH terms: Female
  20. Logunov DV
    Zootaxa, 2014;3894:183-7.
    PMID: 25544631 DOI: 10.11646/zootaxa.3894.1.16
    A new species Uroballus koponeni sp. n. (♀) from Malaysia (Borneo) is diagnosed, illustrated and described. The genus is unusual for jumping spiders in having extremely long spinnerets.
    Matched MeSH terms: Female
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