Strong Genetic Differentiation of Primula sikkimensis in the East Himalaya–Hengduan Mountains

The East Himalaya-Hengduan Mountains region is the center of diversity of the genus Primula, and P. sikkimensis is one of the most common members of the genus in the region. In this study, the genetic diversity and structure of P. sikkimensis populations in China were assessed using inter-simple sequence repeat (ISSR) and chloroplast microsatellite markers. The 254 individuals analyzed represented 13 populations. High levels of genetic diversity were revealed by ISSR markers. At the species level, the expected heterozygosity and Shannon’s index were 0.4032 and 0.5576, respectively. AMOVA analysis showed that 50.3% of the total genetic diversity was partitioned among populations. Three pairs of chloroplast microsatellite primers tested yielded a total of 12 size variants and 15 chloroplast haplotypes. Strong cpDNA genetic differentiation (G _ST = 0.697) and evidence for phylogeographic structure were detected (N _ST = 0.788, significantly higher than G _ST). Estimated rates of pollen-mediated gene flow are approximately 27% greater than estimated rates of seed-mediated gene flow in P. sikkimensis. Both seed and pollen dispersal, however, are limited, and gene flow among populations appears to be hindered by the patchiness of the species’ habitats and their geographic isolation. These features may have played important roles in shaping the genetic structure of P. sikkimensis. A minimum-spanning tree of chloroplast DNA haplotypes was constructed, and possible glacial refugia of P. sikkimensis were identified.     

Probiotic Properties and Cellular Antioxidant Activity of <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> MA2 Isolated from Tibetan Kefir Grains

Lactobacillus plantarum MA2 was isolated from traditional Chinese Tibetan kefir grains. Its antioxidant properties had been demonstrated in vitro and in vivo previously. In the present study, the probiotic characteristics of this strain were further evaluated by investigating its acid and bile salt tolerances, cell surface hydrophobicity, and autoaggregation, respectively. In addition, the cellular antioxidant activity (CAA) assay was applied to test the antioxidant capacity of the isolate in different growth phases. Same method was also used to evaluate the antioxidant capacity of its fermentation supernatant, cell-free extract, and intact cell quantitatively. The results of probiotic characteristic tests showed that MA2 could survive at pH 2.5 and 0.3% bile salt. Meanwhile, the measurements of cell surface hydrophobicity and autoaggregation were 45.29?±?2.15 and 6.30?±?0.34%, respectively. The results of cellular antioxidant activity tests indicated that MA2 had high antioxidant potential. The CAA value of logarithmic phase cell-free extract of MA2 (39,450.00?±?424.05 μmol quercetin equivalents/100 g sample) was significantly higher than that in stationary phase cell-free extract (3395.98?±?126.06 μmol quercetin equivalents/100 g sample) and that of fermentation supernatant in logarithmic phase (2174.41?±?224.47 μmol quercetin equivalents/100 g sample) (p?<?0.05). The CAA method was successively applied to evaluate the antioxidant capacity of MA2 in this study, which suggests that it could be used as a useful method for lactic acid bacteria antioxidant potential evaluation.     

利用免疫抑制小鼠模型检测真菌病毒对黄曲霉菌致病力影响

【目的】构建用于比较黄曲霉（Aspergillus flavus,A. flavus）菌株之间致病力差异的小鼠感染模型,并利用该模型评价真菌病毒AfPV1对宿主A. flavus致病力的影响。【方法】用不同浓度环磷酰胺腹腔注射Institute of Cancer Research （ICR）小鼠,根据白细胞的数量判断小鼠免疫抑制程度;通过滴鼻和尾静脉两种感染方法接种不同浓度的A. flavus孢子量,统计14 d以内小鼠的死亡率,确定A. flavus最佳的孢子接种量;通过小鼠组织的菌落负荷量以及肺部组织的病理观察,确定A. flavus感染是否成功;最后利用该小鼠模型评价真菌病毒AfPV1对寄主A. flavus致病力的影响。【结果】腹腔注射环磷酰胺的浓度为250 mg/kg时,能够达到免疫抑制水平;小鼠组织真菌负荷和病理组织切片观察显示A. flavus成功感染接种的ICR小鼠组织;在滴鼻接种模型中,A. flavus的孢子接种量为40μL（1×10⁶CFU/mL）时比较合适评价A. flavus菌株之间的差异;在尾静脉接种的模型中,A. flavus的孢子...     

Polymorphisms of Genes in Neurotransmitter Systems Were Associated with Alcohol Use Disorders in a Tibetan Population

Studies of linkage and association in various ethnic populations have revealed many predisposing genes of multiple neurotransmitter systems for alcohol use disorders (AUD). However, evidence often is contradictory regarding the contribution of most candidate genes to the susceptibility of AUD. We, therefore, performed a case-control study to investigate the possible associations of genes selected from multiple neurotransmitter systems with AUD in a homogeneous Tibetan community population in China. AUD cases (N = 281) with an alcohol use disorder identification test (AUDIT) score ≥10, as well as healthy controls (N = 277) with an AUDIT score ≤5, were recruited. All participants were genotyped for 366 single nucleotide polymorphisms (SNPs) of 34 genes selected from those involved in neurotransmitter systems. Association analyses were performed using PLINK version 1.07 software. Allelic analyses before adjustment for multiple tests showed that 15 polymorphisms within seven genes were associated with AUD (p<0.05). After adjustment for the number of SNPs genotyped within each gene, only the association of a single marker (rs10044881) in HTR4 remained statistically significant. Haplotype analysis for two SNPs in HTR4 (rs17777298 and rs10044881) showed that the haplotype AG was significantly associated with the protective effect for AUD. In conclusion, the present study discovered that the HTR4 gene may play a marked role in the pathogenesis of AUD. In addition, this Tibetan population sample marginally replicated previous evidence regarding the associations of six genes in AUD.     

人酪酪肽及其衍生物的克隆、表达及活性测定

酪酪肽(peptide tyrosine tyrosine, PYY)是存在于机体肠道的肽类激素,有 PYY_1-36和PYY_3-36两种形式,后者可以降低个体食欲并减少食物摄入。分别通过人工合成基因和PCR定点突变的方法,得到PYY_3-36衍生物PYY_3-36-Gly³⁷及PYY_3-36的基因,然后克隆到pET32a(+)表达载体中,转化大肠杆菌并进行诱导表达。通过亲和层析得到融合蛋白,经肠激酶酶切和二次亲和层析得到目的多肽。在昆明鼠体内检测二者生物活性,结果显示剂量为800μg/kg时PYY_3-36及PYY_3-36-Gly³⁷均可抑制昆明鼠的摄食,且抑制作用可达9h,而PYY_3-36-Gly³⁷组的平均抑制率可达50%,明显高于PYY_3-36。     

The myocardial response to adrenomedullin involves increased cAMP generation as well as augmented Akt phosphorylation

In this work we aimed to observe (1) the changes in adrenomedullin (AM) and its receptor system - calcitonin receptor-like receptor (CRLR) and receptor activity modifying proteins (RAMPs) - in myocardial ischemic injury and (2) the response of injuried myocardia to AM and the phosphorylation of Akt to illustrate the protective mechanism of AM in ischemic myocardia. Male SD rats were subcutaneously injected with isoproterenol (ISO) to induce myocardial ischemia. The mRNA levels of AM, CRLR, RAMP1, RAMP2 and RAMP3 were determined by RT-PCR. Protein levels of Akt, phosphor-Akt, CRLR, RAMP1, RAMP2 and RAMP3 were assayed by Western blot. Results showed that, compared with that of the controls, ISO-treated rats showed lower cardiac function and myocardial injury. The mRNA relative amount of AM, CRLR, RAMP1, RAMP2 and RAMP3 in the myocardia of ISO-treated rats was increased. The elevated mRNA levels of CRLR, RAMP1, RAMP2 and RAMP3 were positively correlated with AM content in injured myocardia. The protein levels of CRLR, RAMP1, RAMP2 and RAMP3 in injured myocardia were increased compared with that of control myocardia. AM-stimulated cAMP generation in myocardia was elevated in the ISO group, and was antagonized by AM(22-52) and CGRP(8-37). Western blot analyses revealed that AM significantly enhanced Akt phosphorylation in injured myocardia, which was blocked by pretreatment with AM(22-52) or CGRP(8-37). Ischemia-injured myocardia hyper-expressed AM and its receptors - CRLR, RAMP1, RAMP2 and RAMP3 - and the response of ischemic myocardia to AM was potentiated, and the level of Akt phosphorylation was also increased, which suggests that changes in cardiac AM/AM receptor might play an important role in the pathogenesis of myocardial ischemic injury.     

养殖密度对史氏鲟消化率、摄食率和生长的影响

以体重（43.90±1.75）g史氏鲟为研究对象,研究了0.525、1.171和2.138 kg·m^-2 3种养殖密度对史氏鲟幼鱼生长、摄食率和消化率的影响,实验时间为60 d.结果表明,养殖密度对史氏鲟的生长、摄食率和消化率具有显著影响.高养殖密度不利于史氏鲟的生长,低密度组中史氏鲟的特定生长率和日增重显著高于高密度组,食物转化率显著低于高密度组;特定生长率和日增重随养殖密度的降低而显著增高.低密度组、中密度组中史氏鲟的消化率无显著差异,但均显著高于高密度组.中密度组摄食率显著低于高密度组和低密度组,低密度组摄食率介于两者之间;食物转化率和消化率呈显著负相关,特定生长率与消化率呈显著正相关.     

茶园间作柑桔杨梅或吊瓜对叶蝉及蜘蛛类群数量和空间格局的影响

为评价茶园间作几种常见经济作物对重要害虫假眼小绿叶蝉及其主要天敌蜘蛛类群数量和空间格局的影响,遂选乌牛早品种纯茶园、乌牛早分别与柑桔、杨梅和吊瓜的间作茶园、以及安吉白茶与吊瓜间作茶园,2007年9月上旬—2008年12月下旬,每旬1次调查茶丛上、中、下层叶蝉和各种蜘蛛的数量。结果表明:(1)与纯茶园相比,间作茶园叶蝉种群数量和蜘蛛类群个体数量显著地增加,间作茶园蜘蛛种数显著地增加;(2)间作茶园茶丛上、中、下层叶蝉、蜘蛛个体数量分布明显区别于纯茶园茶丛上、中、下层叶蝉、蜘蛛个体数量分布;(3)茶丛上层的嫩梢是制作高档茶的原料,而纯茶园茶丛上层叶蝉虫口百分率为54.16%,间作茶园茶丛上层叶蝉虫口百分率皆减小,并且叶蝉高峰期间蜘蛛的跟随效应增强;(4)间作增加了经济收入并减少了防治次数。认为:(1)间作可在一定程度上调控叶蝉种群、蜘蛛类群的数量和空间格局;(2)间作可减轻叶蝉为害造成的产值损失,增强了茶园群落对于叶蝉的自然控制潜能。     

饲料中狐狸、水貂、貉子和狗源性的五重实时荧光PCR检测方法的建立

为了快速鉴别饲料中的狐狸、水貂、貉子和狗源性成分,根据线粒体16S r DNA种间保守序列,设计合成针对狐狸、水貂、貉子和狗的特异性引物和探针,通过对荧光PCR反应体系和反应条件的优化筛选,建立了多重实时荧光PCR方法,在同一PCR反应体系中可以同时完成4种动物源性成分检测。通过对15种其他物种的源性成分的检测,结果表明所设计的引物和探针具有很好的物种特异性,且灵敏度高,狐狸、水貂、貉子和狗的DNA检出限为0.01ng。对40份样品检测,其中5份检测出貉子、狐狸和水貂源性成分。结果表明,该方法可以有效地鉴别出饲料中狐狸、水貂、貉子和狗源性成分,同时适用于相关动物产品中。     

Regulation of autophagy protects against liver injury in liver surgery-induced ischaemia/reperfusion

Transient ischaemia and reperfusion in liver tissue induce hepatic ischaemia/reperfusion (I/R) tissue injury and a profound inflammatory response in vivo. Hepatic I/R can be classified into warm I/R and cold I/R and is characterized by three main types of cell death, apoptosis, necrosis and autophagy, in rodents or patients following I/R. Warm I/R is observed in patients or animal models undergoing liver resection, haemorrhagic shock, trauma, cardiac arrest or hepatic sinusoidal obstruction syndrome when vascular occlusion inhibits normal blood perfusion in liver tissue. Cold I/R is a condition that affects only patients who have undergone liver transplantation (LT) and is caused by donated liver graft preservation in a hypothermic environment prior to entering a warm reperfusion phase. Under stress conditions, autophagy plays a critical role in promoting cell survival and maintaining liver homeostasis by generating new adenosine triphosphate (ATP) and organelle components after the degradation of macromolecules and organelles in liver tissue. This role of autophagy may contribute to the protection of hepatic I/R-induced liver injury; however, a considerable amount of evidence has shown that autophagy inhibition also protects against hepatic I/R injury by inhibiting autophagic cell death under specific circumstances. In this review, we comprehensively discuss current strategies and underlying mechanisms of autophagy regulation that alleviates I/R injury after liver resection and LT. Directed autophagy regulation can maintain liver homeostasis and improve liver function in individuals undergoing warm or cold I/R. In this way, autophagy regulation can contribute to improving the prognosis of patients undergoing liver resection or LT.