排序方式: 共有16条查询结果,搜索用时 9 毫秒
1.
Most tissues display several features of cellular polarization. Besides the ubiquitous epithelial polarization in the Apical–Basal (A/B) axis, many epithelia (and associated organs) display a Planar Cell Polarization (PCP). Recently, a crosstalk between the PCP and A/B polarity determinants has been suggested, i.e. the activity or stability of the PCP factor Frizzled is regulated by the A/B determinants aPKC and Bazooka in the Drosophila eye. We have systematically investigated genetic and physical interactions between the Drosophila A/B factors and the core PCP component Strabismus (Stbm)/Van Gogh (Vang). The A/B determinant Scribble was found to interact both genetically and physically with Stbm/Vang. We demonstrate that Scribble binds Stbm/Vang through its PDZ domain 3 and that it cooperates with Stbm/Vang in PCP establishment. Our data indicate that Scribble, in addition to its role in A/B polarity, has a distinct requirement in PCP establishment in the Drosophila eye and wing. We define a scribble allele that is largely PCP specific. Our data show that Scribble is part of the Stbm/Vang PCP complex and further suggest that it might act as an effector of Stbm/Vang during PCP establishment. 相似文献
2.
Smith J Sadeyen JR Paton IR Hocking PM Salmon N Fife M Nair V Burt DW Kaiser P 《Journal of virology》2011,85(21):11146-11158
3.
Sadeyen JR Trotereau J Velge P Marly J Beaumont C Barrow PA Bumstead N Lalmanach AC 《Microbes and infection / Institut Pasteur》2004,6(14):1278-1286
Asymptomatic Salmonella enterica serovar Enteritidis carrier state in poultry has serious consequences on food safety and public health due to the risks of food poisoning following consumption of contaminated products. An understanding the mechanisms of persistence of Salmonella in the digestive tract of chicken can be achieved by a better knowledge of the defects in the control of infection in susceptible versus resistant animals. The gene expression of innate immune response factors including anti-microbial molecules, inflammatory and anti-infectious cytokines was studied in the caecal lymphoid tissue associated with the carrier state. Expression levels of these genes were assessed by real-time PCR and were compared in two inbred lines of chickens differing in resistance to the carrier state following oral inoculation of S. enterica serovar Enteritidis at 1 week of age. No correlation was observed between resistance/susceptibility to caecal carrier state and level of interleukin (IL)-1beta, IL-8, IL-18, inducible NO synthase (iNOS) and natural resistance associated macrophage protein 1 (NRAMP1). A high baseline level of defensin gene expression was recorded in young animals from the susceptible line. In contrast, a significantly low expression of interferon-gamma (IFN-gamma) gene was observed in these susceptible infected animals in comparison to resistant ones and healthy counterparts. IFN-gamma expression level represents a valuable indication of immunodeficiency associated with persistence of Salmonella in the chicken digestive tract, and IFN-gamma thus represents a factor to consider in the development of prophylactic measures for the reduction of Salmonella carrier state. 相似文献
4.
Saara J. DeWalt Stefan A. Schnitzer Jérôme Chave Frans Bongers Robyn J. Burnham Zhiquan Cai Georges Chuyong David B. Clark Corneille E. N. Ewango Jeffrey J. Gerwing Esteban Gortaire Terese Hart Guillermo Ibarra-Manríquez Kalan Ickes David Kenfack Manuel J. Macía Jean-Remy Makana Miguel Martínez-Ramos Joseph Mascaro Sainge Moses Helene C. Muller-Landau Marc P. E. Parren Narayanaswamy Parthasarathy Diego R. Pérez-Salicrup Francis E. Putz Hugo Romero-Saltos Duncan Thomas 《Biotropica》2010,42(3):309-317
We test the hypotheses proposed by Gentry and Schnitzer that liana density and basal area in tropical forests vary negatively with mean annual precipitation (MAP) and positively with seasonality. Previous studies correlating liana abundance with these climatic variables have produced conflicting results, warranting a new analysis of drivers of liana abundance based on a different dataset. We compiled a pan-tropical dataset containing 28,953 lianas (≥2.5 cm diam.) from studies conducted at 13 Neotropical and 11 Paleotropical dry to wet lowland tropical forests. The ranges in MAP and dry season length (DSL) (number of months with mean rainfall <100 mm) represented by these datasets were 860–7250 mm/yr and 0–7 mo, respectively. Pan-tropically, liana density and basal area decreased significantly with increasing annual rainfall and increased with increasing DSL, supporting the hypotheses of Gentry and Schnitzer. Our results suggest that much of the variation in liana density and basal area in the tropics can be accounted for by the relatively simple metrics of MAP and DSL. 相似文献
5.
Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests 总被引:1,自引:0,他引:1
Muller-Landau HC Condit RS Chave J Thomas SC Bohlman SA Bunyavejchewin S Davies S Foster R Gunatilleke S Gunatilleke N Harms KE Hart T Hubbell SP Itoh A Kassim AR LaFrankie JV Lee HS Losos E Makana JR Ohkubo T Sukumar R Sun IF Nur Supardi MN Tan S Thompson J Valencia R Muñoz GV Wills C Yamakura T Chuyong G Dattaraja HS Esufali S Hall P Hernandez C Kenfack D Kiratiprayoon S Suresh HS Thomas D Vallejo MI Ashton P 《Ecology letters》2006,9(5):575-588
The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into the global carbon budget, and deserves careful assessment. We assembled data from 10 old-growth tropical forests encompassing censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it, and were inconsistent with the predictions of metabolic ecology in all forests. 相似文献
6.
7.
8.
9.
Laczkó I Váró G Bottka S Bálint Z Illyés E Vass E Bertrand JR Malvy C Hollósi M 《Archives of biochemistry and biophysics》2006,454(2):146-154
Octanoyl and palmitoyl groups were coupled to the N-terminus of an analog of the SV40 nuclear localization signal peptide, SV126-133(Ser128), to study the effect of the fatty acid chain length on the complex formation with a single-stranded antisense oligodeoxynucleotide (ODN) and on the cellular uptake of the complex. The strongest binding affinity was observed for the palmitoylated peptide, indicating the better accessibility of the positively charged lysyl and arginyl side-chains to the phosphate groups due to the turn structures stabilized by the palmitoyl group. On increase of the peptide to ODN molar ratio (rM), gradual unstacking of the bases was observed, the maximal rate being reached at rM=10. At rM>10 restacking of the nucleotide bases was detected and the ODN was completely encapsulated in a liposome-like structure made up of palmitoylated peptides. Cell translocation experiments revealed a highly efficient cell transport of the ODN by palmitoylated SV40 peptide at rM>10. 相似文献
10.
Sadeyen JR Trotereau J Protais J Beaumont C Sellier N Salvat G Velge P Lalmanach AC 《Microbes and infection / Institut Pasteur》2006,8(5):1308-1314
Salmonellosis is one of the main causes of food-borne poisoning due to the consumption of contaminated poultry products. In the flocks, Salmonella is able to persist in the digestive tract of birds for weeks without triggering any symptom. In order to identify molecules and genes involved in the mechanism of host resistance to intestinal carrier-state, two different inbred lines of laying hens were orally inoculated with Salmonella Enteritidis. Bacterial colonization and host gene expression were measured in the caecum and its sentinel lymphoid tissue, respectively. Significantly increased expression of chemokine, anti-infectious cytokine, bacterial receptor, antimicrobial mediator and particularly, defensin genes was observed in the line carrying a lower level of bacteria in the caecum. These innate immunity molecules were either constitutively or inductively highly expressed in resistant adult birds and thus present candidate genes to play an important role in the host defence against Salmonella colonization. 相似文献