Expression patterns and association analysis of the porcine DHX58 gene

RIG-1 signalling is responsible for the detection of cytoplasmic viral RNA molecules. DEXH (Asp-Glu-X-His) box polypeptide 58 (encoded by DHX58) is a negative regulator of the RIG-1 signalling pathway. In human, the DHX58 gene can be upregulated and can inhibit the RIG-1 signalling pathway during viral infection. In this study, porcine DHX58 gene expression patterns were studied. According to our results, the porcine DHX58 gene was upregulated not only by the stimulation of Poly I:C but also by the stimulation of 1ipopolysaccharides (LPS). One polymorphism (g.4919G>C), detected in the ninth intron, was significantly associated with some blood parameters including the red cell distribution width of 1-day-old pigs and white blood cell counts, lymphocyte absolute counts, and platelet distribution width of 17-day-old pigs (P < 0.05). Moreover, the individuals with the genotype GG have a significantly higher mean white blood cell count than individuals with genotype CC or GC (P < 0.05). Our study indicates that DHX58 is an important gene that is associated with the immune response in swine.     

Historical shrub–grass transitions in the northern Chihuahuan Desert: modeling the effects of shifting rainfall seasonality and event size over a landscape gradient

We use a spatially explicit landscape model to investigate the potential role of rainfall on shrub–grass transitions in the Jornada Basin of southern New Mexico during the past century. In long‐term simulations (1915–1998) along a 2700 m transect running from a dry lake bed to the foothills of a small mountain, we test two hypotheses: (i) that wetter winters and drier summers may have facilitated shrub encroachment in grasslands, and (ii) that increases in large precipitation events may have increased soil water recharge at deeper layers, thus favoring shrub establishment and growth. Our model simulations generally support the hypothesis that wetter winters and drier summers may have played a key role, but we are unable to reproduce the major shifts from grass‐ to shrub‐domination that occurred in this landscape during the early part of the 1900s; furthermore, the positive shrub response to wetter winters and drier summers was only realized subsequent to the drought of 1951–1956, which was a relatively short ‘window of opportunity’ for increased shrub establishment and growth. Our simulations also generally support the hypothesis that an increase in the number of large precipitation events may also have favored shrub establishment and growth, although these results are equivocal, depending upon what constitutes a ‘large’ event and the timing of such events. We found complex interactions among (i) the amount/seasonality of rainfall, (ii) its redistribution in the landscape via run‐on and runoff, (iii) the depth of the soil water recharge, and (iv) subsequent water availability for the growth and reproduction of shrubs vs. herbaceous plants at various landscape positions. Our results suggest that only a mechanistic understanding of these interactions, plus the role of domestic cattle grazing, will enable us to elucidate fully the relative importance of biotic vs. abiotic factors in vegetation dynamics in this semiarid landscape.     

苦绳的一个新甾体成分

从苦绳(Dregea sinensis Hemsl.),和分出一新的甾体成分,Dresigenin A(I),经化学反应及光谱分析证明其结构为12-O-乙酰基-20-O-(2-甲基丁酰基)二氢肉珊瑚甙元[12-O-acetyl-20-O-(2-methylbutyryl)dihydrosarcostin]。     

Solution structure of the chromomycin-DNA complex

The structure of the chromomycin-DNA complex at the deoxyoctanucleotide duplex level has been determined from one- and two-dimensional proton NMR studies in Mg-containing aqueous solution. The NMR results demonstrate that the antitumor agent binds as a symmetrical dimer to the self-complementary d[T-T-G-G-C-C-A-A] duplex with retention of the 2-fold symmetry in the complex. A set of intermolecular nuclear Overhauser enhancements (NOEs) establishes that two chromomycin molecules in the dimer share the minor groove at the G-G-C-C.G-G-C-C segment in such a way that each hydrophilic edge of the chromophore is located next to the G-G.C-C half-site and each C-D-E trisaccharide chain extends toward the 3'-direction of the octanucleotide duplex. In addition, the A-B disaccharide segment and the hydrophilic side chain of the antitumor agent are directed toward the phosphate backbone. The observed changes in nucleic acid NOEs and coupling patterns on complex formation establish a transition to a wider and shallower minor groove at the central G-G-C-C.G-G-C-C segment required for accommodating the chromomycin dimer. The present demonstration that chromomycin binds as a dimer and switches the conformation of the DNA at its G.C-rich minor groove binding site provides new insights into antitumor agent design and the sequence specificity of antitumor agent-DNA recognition.     

血管平滑肌细胞的钙动力学

血管平滑肌细胞外的Ca~(2+)通过多种通道进入细胞内。Ca~(2+)通道的本质是镶嵌在膜脂质双分子层中的糖蛋白,神经介质和药物可影响Ca~(2+)通道的功能。靠近胞膜的肌质网和胞膜内侧面的高亲和性Ca~(2+)结合位点是血管平滑肌细胞内储存和释放Ca~(2+)的主要部位。胞浆[Ca~(2+)]增高后在钙调蛋白的介导下引起血管收缩。高血压等血管性疾病的发生与其平滑肌细胞的钙动力学异常有关。     

突触后细胞骨架与乙酰胆碱受体簇

乙酰胆碱受体(AChR)簇的形成在神经肌接头的生长过程中是非常关键的一步。突触后细胞骨架参与AChR簇的形成。     

Applied anatomy of the anterolateral femoral flap

A study of the source of the blood supply to the anterolateral femoral flap was carried out on 42 lower limbs of adult cadavers (among them 35 cadavers with injection of red latex and 1 with india ink into the arteries and 6 vascular cast specimens), and the surface locations of the vascular pedicle were detected on 50 healthy adults. It was found that the descending branch of the lateral circumflex femoral vessel was an ideal axial vessel. There are constant perforating branches of the myocutaneous artery or cutaneous branches from the intermuscular space to the anterolateral femoral skin. The area extends about 12 x 30 cm. Within the flap, the anterior branch of the anterolateral cutaneous nerve of the high is located. This flap has been widely used for free transplantation in China since 1983 with satisfactory results.     

高粱对丝黑穗病的抗性及遗传研究

1981—1985年在人工接种的条件下,对1239份高粱品种资源,进行了抗丝黑穗病性鉴定。与此同时,用17个抗性不同的品种系,按照不完全双列杂交设计,进行了高粱对丝黑穗病的抗性遗传研究。结果表明,高粱对丝黑穗病的抗性遗传方式因品种而异。有的品种系具数量性状遗传特点,有的则具有质量性状遗传特点。抗病性属数量性状遗传的品种系,其抗性主要是受加性基因控制。     

中国的红树林

我国红树林主要分布在热带及亚热带沿海盐滩和河川出口的冲积盐性土上,包括24个科,47种,属于东方群系。从广西钦州湾开始经北海港,沿雷州半岛的海安分为两支,一支往南经海南岛的儋县新英港,向东经琼山县的东寨港和文昌县的清澜港,沿着东海岸至崖县的三亚港,又折向北到达东方县的八所港;另一支向东北经湛江的赤坎,阳江的海陵岛,台山的上下川岛,中山的三灶岛,新会的崖门,再沿海岸往北至福建的福鼎和台湾的新竹港。根据我国红树林的主要构成种类、外貌、生境,大致可分为3大群系和10个群落。(1) 矮灌木群系——这个群系多见于纬度稍高的海滩前缘,包括海榄雌群落和桐花树群落。这些群落在演替上处于前期阶段。(2) 高大稠密灌木群系——这个群系由于气温、年降雨量的差异和土壤性质的不同,组成这个群系的种类也有不同,不过都是以红树族的种类为建群种,它包括4个群落:红树群落、红海兰群落和角果木群落,这些群落在演替上属于中期阶段。(3) 乔木群系——这个群系主要分布在海南岛东北和东部海岸,所在地一般地势较高,前缘地带每日潮涨仍有海水浸淹。后缘地带只有每月大潮时才有海水到达,土壤比较固结,它包括木榄群落、海莲和尖瓣海莲群落、海桑群落及半红树林水椰群落。这些群落在演替上是处于后期阶段。组成我国红树林的种类大多数都具有较高的经济价值,如角果木是优质单宁的原料,有些种类经过发酵处理成为高营养的饲料和肥料。此外,沿海浮游生物的产量有红树林比无红树林的地带高达7倍,因此加强对红树林的经营和保护应采取积极态度和有效措施。