A new Illumina MiSeq high-throughput sequencing-based method for evaluating the composition of the Bacteroides community in the intestine using the rpsD gene sequence

Bacteroides is a bacterial genus that is known to closely interact with the host. The potential role of this genus is associated with its ecological status and distribution in the intestine. However, the current 16S V3–V4 region sequencing method can only detect the abundance of this genus, revealing a need for a novel sequencing method that can elucidate the composition of Bacteroides in the human gut microbiota. In this study, a core gene, rpsD, was selected as a template for the design of a Bacteroides-specific primer set. We used this primer set to develop a novel assay based on the Illumina MiSeq sequencing platform that enabled an accurate assessment of the Bacteroides compositions in complex samples. Known amounts of genomic DNA from 10 Bacteroides species were mixed with a complex sample and used to evaluate the performance and detection limit of our assay. The results were highly consistent with those of direct sequencing with a low Bacteroides DNA detection threshold (0.01 ng), supporting the reliability of our assay. In addition, the assay could detect all the known Bacteroides species within the faecal sample. In summary, we provide a sensitive and specific approach to determining the Bacteroides species in complex samples.     

阿德福韦酯联合拉米夫定治疗乙型肝炎DNA阳性肝硬化疗效观察

目的：探讨阿德福韦酯联合拉米夫定治疗HBV DNA阳性乙型肝炎肝硬化的疗效。方法：46例HBV DNA阳性乙肝肝硬化患者随机分为对照组及观察组。在保肝等对症治疗基础上,观察组22例患者联用阿德福韦酯与拉米夫定,对照组24例患者予阿德福韦酯,总疗程均为48周。结果：在治疗12周后,观察组与对照组HBV DNA转阴率分别为54.5%、20.8%（P〈0.05）,ALT复常率分别为63.6%、33.3%（P〈0.05）。治疗24周、48周后上述指标无统计学差异。两组患者未见明显药物不良反应。结论：阿德福韦酯联合拉米夫定治疗HBV DNA阳性乙型肝炎肝硬化起效快,降低病毒载量疗效佳,安全性好。     

伊贝母体细胞无性系的建立及其胚状体的发生

本文报道了伊贝母体细胞无性系的建立及其胚状体的发生。已继代培养三年零六个月共30多代的鳞芽愈伤组织,目前仍有分化能力。通过愈伤组织形态细胞学的观察,发现伊贝母体细胞无性系形成小鳞茎的途径有二:一是由特化了的愈伤组织表皮细胞。经多次分裂发育成不定芽而形成小鳞茎;二是由愈伤组织表层或内层特化了的胚性细胞,经多次分裂发育成胚状体而形成小鳞茎。不定芽和胚状体的形态发生是有区别的。     

Genetic mapping of quantitative trait loci affecting carcass and meat quality traits in Beijing ducks (Anas platyrhynchos)

Quantitative trait loci (QTL) for carcass and meat quality traits were detected in a sample of 224 progeny from four males in line VI and 12 females in line V of Beijing ducks. These lines were selected for high body weight at 42 days of age (line VI) or high egg production at 360 days of age (line V). Traits were weights of the carcass, head, neck, shanks, wings, legs, thighs, breast, heart, liver, crop, gizzard, abdominal fat (AFW) and skin fat, as well as fat thickness in the tail, and pH value, shear force, drip loss (DL) (%) and cooking loss (CL) (%) of the breast. Using a half-sib analysis with a multiple QTL model, linkage between the carcass and meat quality traits and 95 microsatellite markers was investigated. Eight genome-wide significant QTL for weight of crop, skin fat, liver, neck, shanks, wings, DL were detected on linkage groups CAU4 and CAU6. One genome-wide suggestive QTL and one chromosome-wide significant QTL for weight of breast were found on CAU1 and CAU4 respectively. Fifteen chromosome-wide suggestive QTL influencing weight of AFW, breast, crop, heart, carcass, thighs, liver, shanks, gizzard, fat thickness in tail, DL (%) and CL (%) were mapped on CAU2, CAU4, CAU5, CAU6, CAU7, CAU10 and CAU13. In addition, two linked QTL for weight of liver and DL (%) were located on CAU2 and CAU7 respectively. The detection of QTL in ducks is a step towards identification of genes influencing these traits and their use for genetic improvement in this species.     

The Effects of Genetic Variation in FTO rs9939609 on Obesity and Dietary Preferences in Chinese Han Children and Adolescents

The association of the rs9939609 single nucleotide polymorphism in FTO gene with obesity has been extensively investigated in studies of populations of European, African, and Asian ancestry. However, inconsistent results have been reported in Asian populations, and the relationship of FTO variation and dietary behaviors has only rarely been examined in Chinese children and adolescents. The aim of this study was to assess the association of rs9939609 with obesity and dietary preferences in childhood in a Chinese population. Epidemiological data including dietary preferences were collected in interviews using survey questionnaires, and rs9939609 genotype was determined by real-time PCR. The associations of rs9939609 genotypes with obesity and dietary preferences were analyzed by multivariate logistic regression using both additive and dominant models. The results showed that subjects with a TA or AA genotype had an increased risk of obesity compared with the TT participants; the odds ratios (ORs) were 1.47 (95% CI: 1.25–1.71, P = 1.73×10⁻⁶), and 3.32 (95% CI: 2.01–5.47, P = 2.68×10⁻⁶), respectively. After adjusting for age and gender, body mass index, waist circumference, hip circumference, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triglycerides, and low-density lipoprotein cholesterol were higher, and high-density lipoprotein cholesterol was lower in TA and AA participants than in those with the TT genotype. After additionally controlling for body mass index, the association remained significant only for systolic blood pressure (P = 0.005). Compared with TT participants, those with the AA genotype were more likely to prefer a meat-based diet (OR = 2.81, 95% CI: 1.52–5.21). The combined OR for obesity in participants with TA/AA genotypes and preference for a meat-based diet was 4.04 (95% CI: 2.8–5.81) compared with the TT participants who preferred a plant-based diet. These findings indicate the genetic variation of rs9939609 is associated with obesity and dietary preferences in Chinese children and adolescents.     

神秘果种子蛋白质的提取与降糖效用研究

本文研究神秘果种子蛋白质(SDSP)的提取条件及其降糖效用,通过考察固液比、pH值、时间和温度等因素对SDSP提取率的影响来优化提取蛋白质的条件,并利用四氧嘧啶诱导糖尿病小鼠模型分析神秘果种子蛋白质的降糖效果。实验方法如下:将实验组小鼠分为正常对照组、糖尿病模型组、SDSP实验组(200 mg/kg)和阳性对照组(80 mg/kg二甲双胍),灌胃14 d后测量空腹血糖值(FBG),胰岛素含量和体重。实验结果表明SDSP的最佳提取工艺条件为固液比1∶20、pH 8.5、时间120 min、温度50℃。测定SDSP组的FBG含量比模型组降低46%,而胰岛素含量则增加约4倍。实验表明SDSP显著降低糖尿病小鼠空腹血糖值,促进胰岛素的分泌。     

PCR-SSP技术对广东汉族人HLA-DR基因分型

探索具有高分辨率、高特异性和简捷快速的方法对ＨＬＡ－ＤＲ基因分型,为临床器官移植配型和疾病相关性分析提供实用的方法和基础资料．利用ＤＲ１～ＤＲｗ１８序列特异性的１９组引物及１对内参照引物进行ＰＣＲ扩增即ＰＣＲ－ＳＳＰ对ＨＬＡ－ＤＲ进行基因分型,扩增产物经琼脂糖凝胶电泳,溴乙锭染色,在紫外光下观察分型结果．每个被检个体的ＤＲ型别可由特异引物扩增出现的电泳谱带直接判断．双盲检测２２例的结果１００％正确．在１０２例中国广东地区汉族人中,ＤＲ９和ＤＲ２的基因频率最高,分别为０．２２０５和０．１９１２,ＤＲ１０为最低（０．００９８）．与用ＰＣＲ－ＳＳＯ方法分型获得的结果比较,基因型别分布基本一致,但一些等位基因的频率有差异,表明ＨＬＡ－ＤＲ基因频率的分布在不同地区、不同种族的人群间存在着差异．ＰＣＲ－ＳＳＰ法分辨率和特异性虽不及ＰＣＲ－ＳＳＯ法但比血清学方法精细,分型的全过程只需２～４ｈ能满足临床器官移植配型的要求．基因频率调查结果为器官移植配型和疾病相关性分析提供了基础资料．     

A Unidirectional Cell Switching Gate by Engineering Grating Length and Bending Angle

On a microgrooved substrate, cells migrate along the pattern, and at random positions, reverse their directions. Here, we demonstrate that these reversals can be controlled by introducing discontinuities to the pattern. On “V-shaped grating patterns”, mouse osteogenic progenitor MC3T3-E1 cells reversed predominately at the bends and the ends. The patterns were engineered in a way that the combined effects of angle- and length-dependence could be examined in addition to their individual effects. Results show that when the bend was placed closer to one end, migration behaviour of cells depends on their direction of approach. At an obtuse bend (135°), more cells reversed when approaching from the long segment than from the short segment. But at an acute bend (45°), this relationship was reversed. Based on this anisotropic behaviour, the designed patterns effectively allowed cells to move in one direction but blocked migrations in the opposing direction. This study demonstrates that by the strategic placement of bends and ends on grating patterns, we can engineer effective unidirectional switching gates that can control the movement of adherent cells. The knowledge developed in this study could be utilised in future cell sorting or filtering platforms without the need for chemotaxis or microfluidic control.