Loci controlling lymphocyte production of interferon γ after alloantigen stimulation in vitro and their co-localization with genes controlling lymphocyte infiltration of tumors and tumor susceptibility

Low infiltration of lymphocytes into cancers is associated with poor prognosis, but the reasons why some patients exhibit a low and others a high infiltration of tumors are unknown. Previously we mapped four loci (Lynf1–Lynf4) controlling lymphocyte infiltration of mouse lung tumors. These loci do not encode any of the molecules that are involved in traffic of lymphocytes. Here we report a genetic relationship between these loci and the control of production of IFNγ in allogeneic mixed lymphocyte cultures (MLC). We found that IFNγ production by lymphocytes of O20/A mice is lower than by lymphocytes of OcB-9/Dem mice (both H2 ^pz ) stimulated in MLC by irradiated splenocytes of C57BL/10SnPh (H2 ^b ) or BALB/cHeA (H2 ^d ) mice, or by ConA. IFNγ production in MLCs of individual (O20 × OcB-9)F₂ mice stimulated by irradiated C57BL/10 splenocytes and genotyped for microsatellite markers revealed four IFNγ-controlling loci (Cypr4-Cypr7), each of which is closely linked with one of the four Lynf loci and with a cluster of susceptibility genes for different tumors. This suggests that inherited differences in certain lymphocyte responses may modify their propensity to infiltrate tumors and their capacity to affect tumor growth.     

基于集合经验模态分解去趋势的水分利用效率对气候变化响应的高程分异——以“21世纪海上丝绸之路”沿线省份为例

水分利用效率(WUE)是表征陆地碳-水循环耦合关系的重要指标，但其对气候变化响应的高程分异仍不清楚。通过集合经验模态分解(EEMD)去趋势和偏相关方法，以"21世纪海上丝绸之路"沿线省份为研究区，揭示WUE对气候变化的响应及其随高程的分异。研究结果表明：(1)研究区内WUE多年均值由中心向南北递减。不同植被类型的WUE多年均值由高到低依次为：常绿针叶林、混交林、常绿阔叶林、稀树灌木草地、耕地和城市建设用地。(2)51.11%的区域表现出均温与WUE的正相关；而81.46%地区表明温差的扩大会使得WUE增加；有近一半的研究区表明最高温的升高有利于提高WUE，而最低温的作用则相反；有67.99%的区域表明降水增多反而会导致WUE的减少。(3)在大多数土地覆盖类型，日温差和最低温主要与WUE呈正相关，而最高温和降水主要与WUE呈负相关。在常绿针叶林、耕地和城市建设用地，日均温与WUE呈负相关。在其他三种植被类型下则呈正相关。(4)在低海拔地区，均温与WUE呈负相关而在中高海拔地区则转变为正相关关系。而最高温则正好相反。降水与WUE的负相关关系系数随高度的增加而不断加强，而温差和最低温与WUE的正相关关系也随高度的增加而剧烈波动增强。     

Maternal Transfer and Protective Role of the Alternative Complement Components in Zebrafish Danio rerio

Embryos of most fish develop externally and are exposed to an aquatic environment full of potential pathogens, whereas they have little or only limited ability to mount an efficient and protective response. How fish embryos survive pathogenic attacks remains poorly defined. Here we demonstrate that the maternal immunization of female zebrafish with formalin-killed Aeromonas hydrophila causes a significant increase in C3 and Bf contents in the mother, a corresponding rise in the offspring, and induces a remarkable increase in the hemolytic activities in both the mother and offspring. In addition, the embryos derived from the immunized mother are significantly more tolerant to A. hydrophila challenge than those from the unimmunized fish, and blocking C3 and Bf activities by injection of the antibodies against C3 and Bf into the embryos render them more susceptible to A. hydrophila. These results clearly show that the protection of zebrafish embryos against A. hydrophila can be achieved by the maternally-transferred immunity of the complement system operating via the alternative pathway. This appears to be the first report providing in vivo evidences for the protective role of the alternative complement components in the early embryos of zebrafish, paving the way for insights into the in vivo function of other maternally-transferred factors in fish.     

Characterization of the Erwinia carotovora pelB gene and its product pectate lyase.

The pelB gene encodes pectate lyase B, one of three pectate lyases identified in Erwinia carotovora EC. Pectate lyase B was purified from Escherichia coli containing the pelB gene on a recombinant plasmid. The activity of the protein was optimal at a pH of 8.3. The amino acid composition, N-terminal amino acid sequence, and C-terminal peptide sequence were determined and compared with the polypeptide sequence deduced from the DNA sequence of pelB. Purified pectate lyase B started at amino acid 23 of the predicted sequence, suggesting that a 22-amino-acid leader peptide had been removed. Pectate lyase B of E. carotovora EC and pectate lyase B of E. chrysanthemi EC16 contain 352 and 353 amino acids, respectively (N. T. Keen, S. Tanaki, W. Belser, D. Dahlbeck, and B. Staskawicz, J. Bacteriol. 168:595-606, 1986). The two proteins are 72% homologous on the basis of DNA sequence data, and 75% of the amino acids are identical.     

Structural analysis of the locus containing the human C-reactive protein gene and its related pseudogene

The gene for human C-reactive protein (CRP) is mapped within a 34-kilobase pair genomic DNA segment identified by chromosome walking through overlapping DNA fragments cloned into a lambda phage library. Within 16 kilobase pairs upstream and downstream of the locus for the authentic CRP gene, only one other sequence homologous to that for CRP could be found. Sequencing analysis indicates this sequence to be a pseudogene with 50-80% region-specific homology. Comparison of the authentic CRP gene cloned from genomic DNA libraries independently prepared from three patients indicates no difference in the 5' and 3' flanking region, promoter region, or coding sequence. Only a polymorphism in the length of the poly(GT) stretch located in the intron is observed. There appears to be only one gene locus and copy per haploid chromosome for the authentic CRP gene and its pseudogene.