Herbivory-induced glucose transporter gene expression in the brown planthopper,Nilaparvata lugens

Nilaparvata lugens, the brown planthopper (BPH) feeds on rice phloem sap, containing high amounts of sucrose as a carbon source. Nutrients such as sugars in the digestive tract are incorporated into the body cavity via transporters with substrate selectivity. Eighteen sugar transporter genes of BPH (Nlst) were reported and three transporters have been functionally characterized. However, individual characteristics of NlST members associated with sugar transport remain poorly understood. Comparative gene expression analyses using oligo-microarray and quantitative RT-PCR revealed that the sugar transporter gene Nlst16 was markedly up-regulated during BPH feeding. Expression of Nlst16 was induced 2 h after BPH feeding on rice plants. Nlst16, mainly expressed in the midgut, appears to be involved in carbohydrate incorporation from the gut cavity into the hemolymph. Nlst1 (NlHT1), the most highly expressed sugar transporter gene in the midgut was not up-regulated during BPH feeding. The biochemical function of NlST16 was shown as facilitative glucose transport along gradients. Glucose uptake activity by NlST16 was higher than that of NlST1 in the Xenopus oocyte expression system. At least two NlST members are responsible for glucose uptake in the BPH midgut, suggesting that the midgut of BPH is equipped with various types of transporters having diversified manner for sugar uptake.     

Hyaluronan deposition and correlation with inflammation in a murine ovalbumin model of asthma

Asthma is a chronic inflammatory disease of the airways characterized by airway remodeling, which includes changes in the extracellular matrix (ECM). However the role of the ECM in mediating these changes is poorly understood. Hyaluronan (HA), a major component of the ECM, has been implicated in asthma as well as in many other biological processes. Our study investigates the processes involved in HA synthesis, deposition, localization and degradation during an acute and chronic murine model of ovalbumin (OVA)-induced allergic pulmonary inflammation. Mice were sensitized, challenged to OVA and sacrificed at various time points during an 8-week challenge protocol. Bronchoalveolar lavage (BAL) fluids, blood, and lung tissue were collected for study. RNA, HA, protein and histopathology were analyzed. Analyses of lung sections and BAL fluids revealed an early deposition and an increase in HA levels within 24 h of antigen exposure. HA levels peaked at day 8 in BAL, while inflammatory cell recovery peaked at day 6. Hyaluronan synthase (HAS)1 and HAS2 on RNA levels peaked within 2 h of antigen exposure, while hyaluronidase (HYAL)1 and HYAL2 on RNA levels decreased. Both inflammatory cell infiltrates and collagen deposition co-localized with HA deposition within the lungs. These data support a role for HA in the pathogenesis of inflammation and airway remodeling in a murine model of asthma. HA deposition appears largely due to up regulation of HAS1 and HAS2. In addition, HA appears to provide the scaffolding for inflammatory cell accumulation as well as for new collagen synthesis and deposition.     

主要尿蛋白(MUPs)参与化学信息交流和糖脂代谢

主要尿蛋白（MUPs）属于脂质运载蛋白家族,具有保守的中心疏水β链桶状特征性结构域,具有调节种属内与种属间个体间化学信息交流的功能.MUPs主要在肝合成并分泌入血,作为载体与信息素等亲脂性小分子结合,延长其半衰期,一并从肾过滤排泄入尿液,延缓尿迹中信息素的挥发,从而延长信息素的作用时间.啮齿类动物的MUPs本身具有高度多态性,能够发挥类似信息素的作用直接编码个体信息,调节种属内的生物活动.此外,MUPs还能够发挥利它素的功能引起其它种属的畏惧反应.新近研究发现,MUPs受到机体营养状态的调节,与代谢性疾病及糖脂代谢密切相关,但机制尚不清楚.MUPs的功能和机制探索对于化学信息交流与糖脂代谢研究具有重要意义.本文旨在对MUPs的最新研究结果展开简要综述及讨论.     

基于表型性状和SSR分子标记的云南省水稻主要育成品种（系）的遗传相似性分析

为了揭示云南省水稻主要育成品种（系）的遗传相似性。本文利用株高等17个表型性状和48个微卫星（SSR）分子标记,对云南省18个育种部门（或课题组）60年代以来选育的40个品种（系）进行遗传相似性评价。结果显示表型遗传相似性低于DNA水平。40个品种（系）基于17个表型性状的平均遗传相似系数为0.244,籼型为0.289,粳型为0.309,籼粳亚种间为0.162;基于48个SSR分子标记的平均遗传相似系数为0.383,籼型为0.318,粳型为0.478,籼粳亚种间为0.267。48个SSR分子标记共检测到等位基因214个,每个标记2～8,平均4.458个;平均有效等位基因数为2.8336,变幅为1.1515～5.2981;多态性信息含量（PIC）平均值为0.6058,变幅为0.2118～0.8816;基因型多样性指数（H′）平均值为1.1328,变幅为0.3768～1.8087。RM84、RM249、RM152、RM222和RM528是评价云南省水稻选育品种（系）遗传相似性比较理想的SSR分子标记。聚类分析显示,云南省水稻主要选育品种（系）表现为亚种间遗传差异明显,亚种内遗传差异较小,粳型遗传相似性高于籼型。表明云南省选育的粳型品种（系）遗传多样性低,且同一育种部门（或育种人）选育的品种遗传相似度高。     

The MHC I immunopeptidome conveys to the cell surface an integrative view of cellular regulation

Self/non‐self discrimination is a fundamental requirement of life. Endogenous peptides presented by major histocompatibility complex class I (MHC I) molecules represent the essence of self for CD8 T lymphocytes. These MHC I peptides (MIPs) are collectively referred to as the immunopeptidome. From a systems‐level perspective, very little is known about the origin, composition and plasticity of the immunopeptidome. Here, we show that the immunopeptidome, and therefore the nature of the immune self, is plastic and moulded by cellular metabolic activity. By using a quantitative high‐throughput mass spectrometry‐based approach, we found that altering cellular metabolism via the inhibition of the mammalian target of rapamycin results in dynamic changes in the cell surface MIPs landscape. Moreover, we provide systems‐level evidence that the immunopeptidome projects at the cell surface a representation of biochemical networks and metabolic events regulated at multiple levels inside the cell. Our findings open up new perspectives in systems immunology and predictive biology. Indeed, predicting variations in the immunopeptidome in response to cell‐intrinsic and ‐extrinsic factors could be relevant to the rational design of immunotherapeutic interventions.     

Expression of the Cercosporin Transporter, <Emphasis Type="Italic">CFP</Emphasis>, in Tobacco reduces Frog-eye Lesion Size

The cercosporin Major Facilitator Superfamily (MFS) transporter, CFP, under the control of the CaMV 35S promoter, was introduced into the Xanthi cultivar of tobacco by Agrobacterium-mediated transformation. CFP⁺ transgenic plants were physically indistinguishable from non-transgenic Xanthi and progressed normally through growth to seed set. Accumulation of CFP in the leaf membrane fraction of CFP⁺ transgenic plants was associated with decreased cercosporin phytotoxicity. Frog-eye leaf lesions on CFP⁺ transgenic plants infected with Cercospora nicotianae conidia were smaller but were similar in number to those on non-transgenic plants. We conclude that transgenic expression of CFP may have relevance for a disease control strategy in Cercospora-plant pathosystems where cercosporin is implicated in pathogen virulence.     

Impact of Juvenile Stocking Size on the Major Carp Production in a Minor Reservoir,Bibinagar, India

The present study deals with the impact of juvenile stocking sizes of the major carp on production in a minor reservoir, Bibinagar, Nalgonda, India. Reservoir surface area equaled over 23.8 ha and water from the reservoir was used for irrigation and fisheries. Four experiments were conducted for 4 years from 2000–2001 to 2003–2004. The experiments were planned in such a way that every year juvenile stocking size was held constant and subsequent fish production analyzed. During the first year’s experiment (2000–2001) a stocking size of 25–30 mm (fry) was maintained. Similarly 50–55 (advanced fry), 75–80 mm (fingerling) and 100–105 mm (advanced fingerling) were stocked during 2001–2002, 2002–2003 and 2003–2004 respectively. Uniform yearly stocking densities (2000/ha) were established in each experiment in the month of July and fish were harvested in June of the subsequent year. Major carp production was enhanced with larger stocking size. Yearly productions equaled 144.00, 231.48, 632.91 and 1005.03 kg/ha/year with the above stocking sizes. Variation in stocking sizes had significant (P<0.05) effects on fish production. The number of fish per kg production decreased gradually with increases in stocking size with an average value of 3.97. Reservoir production of catla was the most abundant species, followed by rohu, common carp, mrigal and grass carp. These results show that stocking size has a great impact on fish production and the stocking of advanced fingerlings will provide maximum carp production in minor reservoirs in India.     

Association between major histocompatibility complex class II DRB alleles and parasite load in the hairy-footed gerbil, Gerbillurus paeba, in the southern Kalahari

We investigated the importance of the MHC-constitution (major histocompatibility complex-constitution) on the endoparasite load in free-range hairy-footed gerbils (Gerbillurus paeba) in the southern Kalahari Desert. While the number of alleles of the duplicated DRB exon 2 gene had no significant effects on the individual status of being 'not infected' or 'infected' and on the number of helminth morphotype infections per individual, it significantly affected the faecal egg count values. One allele (Gepa-DRB*15) was only found in uninfected mice. Our results support the hypotheses that MHC polymorphism in G. paeba is maintained by pathogen-driven selection. The present study is the first investigation on associations between duplicated DRB gene loci and the parasite load in mammals.     

Parasite burden and constitution of major histocompatibility complex in the Malagasy mouse lemur, Microcebus murinus

We investigated the importance of the major histocompatibility complex (MHC) constitution on the parasite burden of free-ranging mouse lemurs (Microcebus murinus) in four littoral forest fragments in southeastern Madagascar. Fourteen different MHC class II DRB-exon 2 alleles were found in 228 individuals with high levels of sequence divergence between alleles. More nonsynonymous than synonymous substitutions in the functional important antigen recognition and binding sites indicated selection processes maintaining MHC polymorphism. Animals from the four forest fragments differed in their infection status (being infected or not), in the number of different nematode morphotypes per individual (NNI) as well as in the fecal egg counts (FEC) values. Heterozygosity in general was uncorrelated with any of these measures of infection. However, a positive relationship was found between specific alleles and parasite load. Whereas the common allele Mimu-DRB*1 was more frequently found in infected individuals and in individuals with high NNI and FEC values (high parasite load), the rare alleles Mimu-DRB*6 and 10 were more prevalent in uninfected individuals and in individuals with low NNI and FEC values (low parasite load). These three alleles associated with parasite load had unique amino acid motifs in the antigen binding sites. This distinguished them from the remaining 11 Mimu-DRB alleles. Our results support the hypothesis that MHC polymorphism in M. murinus is maintained through pathogen-driven selection acting by frequency-dependent selection. This is the first study of the association of MHC variation and parasite burden in a free-ranging primate.     

Inducible cyclooxygenase released prostaglandin mediates immunosuppression in acute phase of experimental Trypanosoma cruzi infection

We investigated the possible role of prostaglandins produced by COX-2 in the immunosuppression observed during Trypanosoma cruzi infection. Con-A-stimulated splenocytes isolated from mice on days 5, 10, and 15 of infection released large amounts of PGE2 and this release was inhibited by the treatment of animals with sodium salicylate or meloxicam. The treatment of the animals with these drugs enhanced the release of IL-2 by splenocytes from T. cruzi-infected animals and significantly reduced the blood parasitemia and delayed the mortality of the infected mice. Furthermore, the release of TNF-alpha, IFN-gamma, IL-4, and IL-10 by Con-A-stimulated splenocytes obtained from infected mice on days 5, 10, and 15 of the infection was significantly inhibited by treatment of the animals with salicylate or meloxicam. In conclusion, the results suggest that the prostaglandins produced mainly by COX-2 mediate the immunosuppression observed in the acute phase of T. cruzi infection.