大腹圆蛛主壶腹腺cDNA文库构建和丝蛋白基因筛选

首次通过反转录-置换法和使用pUC18质粒成功构建大腹圆蛛（Araneus ventricosus)主壶腹腺（major ampullate gland)cDNA基因文库,并以鸟枪法从中筛选出具有典型重复结构的大腹圆蛛主壶腹丝蛋白cDNA基因AvF1,大小为1744bp,编码区为1572bp,编码氨基酸524个,分子量为42489.55Da,典型的重复结构为（GGP）nGGX。与现有已知的蛛丝蛋白基因中三带金蛛（Argiope trifas-ciata)鞭毛样丝基因（AtfF)有最高的同源性69.3%。大腹圆蛛主壶腹腺cDNA文库的构建和蛛丝蛋白新基因的克隆,为提供大腹圆蛛蛛丝蛋白基因背景和进一步研究蛛丝蛋白奠定了基础。     

Sexual size dimorphism and Rensch's rule in Canidae

The size variation between males and females of a species is a phenomenon known as sexual size dimorphism (SSD). The observed patterns of variation in SSD among species has led to the formulation of Rensch's rule, which establishes that, in species showing a male size bias, SSD increases with an increase in the body size of the species. However, for species in which there is a female size bias, the SSD would decrease when the body size of the species increases. In the present study, we examined the variation in body size and SSD of 33 species of canids from estimates of body mass and body length. We studied its relationship with life‐history characteristics and tested Rensch's rule using phylogenetic generalized least squares and phylogenetic reduced major axis regressions, respectively. We observed the existence of correlation between body mass and body length, although the SSDs from these estimators are uncorrelated. SSD did not show the pattern predicted by Rensch's rule. SSD also did not show any correlation with life‐history traits. It is likely that the low SSD observed in canids is related to the monogamy observed in the family, which is a rare situation in mammals.     

高原湖泊城市生态安全格局构建——以大理市为例

合理构建生态安全格局是高原湖泊城市健康发展的重要保障。以大理市为研究区,将生态系统健康和生态系统服务统筹到生态安全评估,尝试采用土地发展概率修正生态阻力面,运用电路理论构建生态安全格局,并提出优化方案。结果表明：大理市生态安全水平呈现出“高-低-高”圈层结构空间分布特征;确定生态源地53块,生成顾及未来土地发展的生态阻力面,识别生态廊道111条,筛选生态夹点23处,划分三级生态改善区。提出以洱海为一核,以苍山和南部林区为两屏,以大理市东北部生态保护区、海东生态修复区和满江—凤仪生态城市建设区为三区,以城镇区之间的多个生态修复区为多组团共同构成“一核、两屏、三区、多组团”的生态安全优化格局。将生态系统健康和生态系统服务统筹到生态安全评估及利用土地发展概率修正阻力面所构建的生态安全格局,能更加真实的反映未来发展趋势下生态安全格局构建的需要,为城市生态安全格局构建方法提供了新视角和新方法,以期为城市生态文明建设的区域理论提供借鉴,助力高原湖泊城市的生态宜居。     

中国东西部中小城市景观格局及其驱动力

中小城市的数量及其所承载的城市人口迅速增加是当今和将来全球城市化的最为显著的特征之一.因此,对中小城市的发展规律及其城市化带来的生态和环境影响的研究日趋重要.然而,迄今为止的大多数有关城市化的研究聚焦于大型城市.通过对长三角地区和新疆地区24个中小城市的景观格局分析,结合人口经济数据,探究这两个地区总体城市景观格局的变化,城市间景观格局变化的变异性,以及城市景观格局变化的驱动力,并在此基础之上进行两地区间的对比分析.结果表明,1986年至2000年15a间,长三角地区和新疆地区中小城市的总体景观格局变化基本相似,景观的破碎化程度均不断上升,斑块形状更趋于不规则,景观多样性呈小幅增加;长三角地区中小城市间景观格局变异性下降,而新疆地区中小城市间景观格局变异性上升.长三角地区中小城市景观格局变化的驱动力主要是人口的增加和流动所导致的城市景观变化,新疆地区则为人口的增加和流动所导致的耕地景观面积增加.研究结果有助于解决我国中小城市急速发展所带来的一些生态和环境问题,以及通过土地利用规划来改善我国中小城市的可持续发展.     

A Single Genetic Determinant that Prevents Sex Reversal in C57BL-YPOS Congenic Mice

Sex determination in the mammalian embryo begins with the activation of a gene on the Y chromosome which triggers a cascade of events that lead to male development. The mechanism by which this gene, designated SRY in humans and Sry in mice (sex determining region of the Y chromosome), is activated remains unknown. Likewise, the downstream target genes for Sry remain unidentified at present. C57BL mice carrying a Y chromosome from Mus musculus musculus or molossinus develop normally as males. In contrast, C57BL/6 mice with the Y chromosome from M. m. domesticus often show sex reversal, i.e., develop as XY females. It has been documented that C57BL mice with the Y chromosome from Poschiavinus (Y^POS), a domesticus subtype, always develop as females or hermaphrodites. This suggests that a C57BL gene either up- or downstream of Sry is ineffective in interacting with Sry, which then compromises the processes that lead to normal male sex development. Nonetheless, by selective breeding, we have been able to generate a sex reversal-resistant C57BL/6-congenic strain of mice in which the XY^POS individuals consistently develop as normal males with bilateral testes. Because the resistance to sex reversal was transferred from strain 129S1/Sv (nonalbino) by simple selection over 13 backcross generations, it is inferred that a single autosomal gene or chromosomal region confers resistance to the sex reversal that would otherwise result. XY^POS normal males generated in these crosses were compared to XY^POS abnormal individuals and to C57BL/6 controls for sexual phenotype, gonadal weight, serum testosterone, and major urinary protein (MUP) level. A clear correlation was found among phenotypic sex, MUP level, and testis weight in the males and in the incompletely masculinized XY^POS mice. The fully masculinized males of the congenic strain resemble C57BL/6 males in the tested parameters. DNA analysis confirmed that these males, in fact, carry the Y^POS Sry gene.     

Mammalian non-classical major histocompatibility complex I and its receptors: Important contexts of gene,evolution, and immunity

The evolutionary conserved, less-polymorphic, nonclassical major histocompatibility complex (MHC) class I molecules: Qa-1 and its human homologue human leukocyte antigen-E (HLA-E) along with HLA-F, G and H cross-talk with the T-cell receptors and also interact with natural killer T-cells and other lymphocytes. Moreover, these nonclassical MHC molecules are known to interact with CD94/NKG2 heterodimeric receptors to induce immune responses and immune regulations. This dual role of Qa-1/HLA-E in terms of innate and adaptive immunity makes them more interesting. This review highlights the new updates of the mammalian nonclassical MHC-I molecules in terms of their gene organization, evolutionary perspective and their role in immunity.     

Great tits (Parus major) flexibly learn that herbivore‐induced plant volatiles indicate prey location: An experimental evidence with two tree species

1. When searching for food, great tits (Parus major) can use herbivore‐induced plant volatiles (HIPVs) as an indicator of arthropod presence. Their ability to detect HIPVs was shown to be learned, and not innate, yet the flexibility and generalization of learning remain unclear.
2. We studied if, and if so how, naïve and trained great tits (Parus major) discriminate between herbivore‐induced and noninduced saplings of Scotch elm (Ulmus glabra) and cattley guava (Psidium cattleyanum). We chemically analyzed the used plants and showed that their HIPVs differed significantly and overlapped only in a few compounds.
3. Birds trained to discriminate between herbivore‐induced and noninduced saplings preferred the herbivore‐induced saplings of the plant species they were trained to. Naïve birds did not show any preferences. Our results indicate that the attraction of great tits to herbivore‐induced plants is not innate, rather it is a skill that can be acquired through learning, one tree species at a time.
4. We demonstrate that the ability to learn to associate HIPVs with food reward is flexible, expressed to both tested plant species, even if the plant species has not coevolved with the bird species (i.e., guava). Our results imply that the birds are not capable of generalizing HIPVs among tree species but suggest that they either learn to detect individual compounds or associate whole bouquets with food rewards.

     

Assigning alleles to different loci in amplifications of duplicated loci

Duplicated loci, for example those associated with major histocompatibility complex (MHC) genes, often have similar DNA sequences that can be coamplified with a pair of primers. This results in genotyping difficulties and inaccurate analyses. Here, we present a method to assign alleles to different loci in amplifications of duplicated loci. This method simultaneously considers several factors that may each affect correct allele assignment. These are the sharing of identical alleles among loci, null alleles, copy number variation, negative amplification, heterozygote excess or heterozygote deficiency, and linkage disequilibrium. The possible multilocus genotypes are extracted from the alleles for each individual and weighted to estimate the allele frequencies. The likelihood of an allele configuration is calculated and is optimized with a heuristic algorithm. Monte‐Carlo simulations and three empirical MHC data sets are used as examples to evaluate the efficacy of our method under different conditions. Our new software, mhc‐typer V1.1, is freely available at https://github.com/huangkang1987/mhc-typer .     

小鼠基质重塑相关7(MXRA7)基因产物在肝内互作蛋白质的鉴定（英文）

基质重塑相关7(matrix remodeling associated 7,MXRA7)基因于2002年被命名,但无论在人类或其他动物体系,该基因或其蛋白质产物的功能均未知。直至我们最近的研究表明,该基因可能参与眼睛发育或肝损伤及修复。在本研究中,应用酵母双杂交策略,用小鼠MXRA7诱饵载体对小鼠肝cDNA文库进行筛选,发现23种蛋白质(MUP1, Cpt1a, Mat1a, aldh1l1, Cytb, H2-K1, Psmb1, marc2, Atp5j2, Sec24D, Trf, Rdh7, Apoe, Glud1, Gmfb, Alb, Hdlbp, Pzp, Etnk2, Nrn1, Serpina1a, Apoa2, GNMT)可能直接或间接地与MXRA7蛋白发生相互作用。其中,主要尿蛋白1(major urinary protein,MUP1)或其同家族蛋白质占所有候选克隆的1/6,提示其很可能是小鼠肝内与MXRA7蛋白有较强相互作用的蛋白质。通过基因重组在Hepa 1-6肝癌细胞系中同时过表达MXRA7和MUP1蛋白,荧光染色证明这两种蛋白质在细胞内共定位,应用抗MXRA7或MUP1的抗体进行Pull-down检测,则证明二者共同存在于细胞裂解液中。另外,重组MXRA7蛋白和MUP1蛋白在无任何其他蛋白质的缓冲液体系中直接形成复合体。因此,至少在小鼠肝组织体系中,MXRA7蛋白可能通过与MUP1等蛋白质的相互作用而发挥作用。     

Crystallization of alpha 1-acid glycoprotein

A possible link between cellular cyclic AMP content and Na+K+ATPase activity was investigated in homogenates of rat kidney. Enzyme kinetics of Mg2+ and Na+K+ATPase were run in the presence of cyclic AMP, dibutyryl cAMP and compounds expected to elevate cyclic AMP levels such as forskolin, a potent adenylate cyclase activator, IBMX, an inhibitor of phosphodiesterases, and the beta-agonist isoproterenol. Medullary Na+K+ATPase is strongly inhibited by cyclic AMP whereas cortical Na+K+ATPase was stimulated in the same conditions. The correlation between ATPase activity and cellular cyclic AMP content supports the concept of a possible regulation of the enzyme by cyclic AMP.