Effect of polymorphisms linked to LEP gene on its expression on adipose tissues in beef cattle

In cattle, genetic markers at the leptin (LEP) gene and at those linked to the gene have been described as affecting calving interval (markers LEPSau3AI and IDVGA51), or daily weight gain (BMS1074 and BM1500). This work investigated the effect of these alleles on LEP mRNA levels in cattle subcutaneous and omental adipose tissues. A sample of 137 females of a Brangus‐Ibage beef cattle herd was analysed to evaluate the distribution of the polymorphisms; then, animals having at least one of the IDVGA51*181 (allele 181 at marker IDVGA51; six animals), LEPSau3AI*2 (four), BMS1074*151 (13), BM1500*135 (six) alleles and a control group composed of animals without any of these alleles (four animals) were submitted to surgery to obtain omental and subcutaneous adipose tissues. Leptin mRNA expression was quantified by TaqMan RT‐PCR, using 18S rRNA as internal control and adjusted for the effect of body condition score, through regression analysis. Omental fat had LEP gene expression 33% lower than the subcutaneous tissue. Carriers of IDVGA*181 and BMS1074*151 showed subcutaneous fat leptin mRNA levels higher than the controls. Leptin controls feed intake and coordinates reproduction; therefore, animals with higher LEP gene expression will probably have lower daily weight gain than others with similar forage offer and nutritional condition and probably will also have longer calving interval.     

Identification of polymorphisms and association analysis with meat quality traits in the porcine KIAA1717 and HUMMLC2B genes

Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3′ untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.     

Transport of nutrients and electrolytes across the intestinal wall in pigs

In recent years, intestinal transport processes have been studied in detail regarding both, functional and structural aspects. For monosaccharides different systems have been demonstrated for apical uptake: this includes the high-affinity SGLT1 as a distinct d-glucose system and GLUT5 for fructose. Specifically in pigs a low affinity, high-capacity system for d-glucose and d-mannose with no preference for Na⁺ over K⁺ and a very low affinity system are suggested as further uptake systems. As in other species, basolateral extrusion is mediated by GLUT2. The distributions of monosaccharide transport along the gastrointestinal axis as well as the potential role of paracellular monosaccharide absorption have not yet been clarified.

Amino acids can principally be absorbed by the paracellular and transcellular pathway whereas transcellular transport can either be mediated by facilitated diffusion or secondary active Na⁺-coupled transport. This includes different transport systems for neutral, anionic and cationic acids. In addition, the presence of the di-/tripeptides transport system PEPT1 which depends on an inwardly directed H⁺-gradient has also been confirmed for the pig small intestine, its quantitative proportion is still under debate.

Short chain fatty acids (SCFA) are the major end products of microbial carbohydrate fermentation which occurs along the gastrointestinal tract with the highest production rates in the large intestines. At least two uptake mechanisms have to be assumed, i.e., non-ionic diffusion and anionic exchange via SCFA⁻/HCO₃⁻-exchange. Controversial views still exist to what extent SCFA are metabolized within the epithelial tissue.

Segmental differences between small and large intestines have been demonstrated for Na⁺ absorption. Whereas in the small intestines the major part of Na⁺ absorption is mediated by coupled nutrient transport systems, aldosterone sensitive Na⁺ channels and Na⁺/H⁺-exchange are the dominant mechanisms in the hindgut. For Cl⁻ paracellular transport and anionic Cl⁻/HCO₃⁻-exchange are the major absorptive mechanisms. Cl⁻ secretion is mediated by apical channels which may be activated by toxins of different origin. Different types of Cl⁻ channels have been identified, such as Cystic Fibrosis Transmembrane Regulator (CFTR), Ca-activated Cl⁻ channels (CLCA) and Outwardly Rectifying Cl⁻ Channels (ORCC). Whereas CFTR has clearly been shown for jejunal and colonic epithelial and goblet cells controversy still exists on the relevance of CLCA and ORCC in pigs.

For Ca²⁺ there is evidence that both recently published channels TRPV5 and TRPV6 are also expressed in pig intestinal tissues, however, this has not yet been shown on protein level. From several functional approaches it was demonstrated that phosphate uptake can be mediated by both, a Na⁺-dependent transcellular component and paracellularly. On a molecular basis it is uncertain whether the transport protein of transcellular mechanism belongs to the NaPi-IIb cotransporter family.     

抗盐酸克伦特罗单链抗体基因的克隆、序列分析及表达

提取分泌抗盐酸克伦特罗单克隆抗体杂交瘤细胞株的总RNA,通过RT-PCR技术,扩增VH和VL,用一段柔性肽链-(G4S)3将VH和VL连接成ScFv。测序后经NCBI Blast分析,所得ScFv具有重组功能性鼠抗体可变区基因的特征。将所得目的基因与pET-22b( )连接,转化E.coli BL21,用IPTG诱导表达,表达蛋白经SDS-PAGE分析,37℃培养5 h表达量较大,25℃诱导表达以可溶性为主。     

Effects of deficit irrigation strategies on cluster microclimate for improving fruit composition of Moscatel field-grown grapevines

The grapevine plays a very important role in the economic, social and cultural sectors of many regions; however vineyards are often grown in regions under stressful conditions and thus they are vulnerable to climate change. The objective of this research was to investigate the effect of partial root-zone drying (PRD) irrigation on vine water relations, vegetative growth, plant microclimate, berry composition and yield components, compared to conventional deficit irrigation (DI, 50% ETc), full irrigation (FI, 100% of ETc) and non-irrigated vines (NI). The study was undertaken in mature ‘Moscatel’ grapevines (Vitis vinifera L.) grown in Pegões, South of Portugal. Compared to the other irrigated treatments, PRD vines showed a better microclimate at the cluster zone with higher incident photosynthetic photon flux density (PPFD). Within the more open canopies of NI and PRD treatments, berry temperatures were higher than those of denser ones (DI and FI). Compared to the conventional irrigation technique the better microclimate observed in PRD vines was a consequence of a reduction in vine growth, where lower values of leaf layer number, leaf area, canopy wideness, water shoots and shoot weight were observed. In PRD vines we observed a tendency to a development of a deeper root system, while DI and FI showed a more homogeneous root distribution throughout the different soil layers. PRD showed an improvement in berry quality with higher values of flavour precursors, and total phenols concentration without any significant yield reduction compared to DI and FI.     

<Emphasis Type="Italic">Spongospora subterranea</Emphasis> soil contamination and its relationship to severity of powdery scab on potatoes

We investigated soil contamination by Spongospora subterranea f. sp. subterranea (Sss) and disease severity of powdery scab in 29 potato fields in Hokkaido, Japan, using a hydroponic culture method with tomato seedlings as bait plants. The quantity of Sss infection on the roots of bait plants was evaluated using the polymerase chain reaction (PCR) and expressed in terms of the infection potential in the soil. The infection potential was positively correlated with the disease severity of harvested tubers, whereas the spore ball density determined using PCR had an indistinct relationship with disease severity. The infection potential can be useful in evaluating soil contamination and in applying countermeasures against powdery scab.     

套式反转录—聚合酶链反应检测恙螨及鼠肺内肾综合征出血热病毒RNA

选择覆盖肾综合征出血热病毒（ＨＦＲＳＶ）膜蛋白（ＭＰ）基因的保守区核苷酸序列合成２对引物,采用异硫氰酸胍一步抽提ＲＮＡ,建立了ＲＴ－ＰＣＲ检测鼠体恙螨及游离恙螨体内ＨＦＲＳＶ－ＲＮＡ的方法,扩增产物经凝胶电泳及斑点印迹杂交证实具有特异性。结果显示,ＨＦＲＳＶ抗原阳性鼠体恙螨５０只组、１０只组、游离螨５０只组,ＨＦＲＳＶ抗原阳性鼠肺１０００ｍｇ、５００ｍｇ组经ＲＴ－ＰＣＲ检测为阳性;ＨＦＲＳＶ抗原阳性鼠体恙螨５只组,ＨＦＲＳＶ抗原阴性鼠体恙螨５０只和１０只组,游离螨１０只和５只组,鼠肺ＨＦＲＳＶ抗原阳性１００ｍｇ组均未见有明显扩增带。进一步用套式反转录－聚合酶链反应（ＮｅｓｔｅｄＲＴ－ＰＣＲ）检测,在ＲＴ－ＰＣＲ未测出ＨＦＲＳＶ－ＲＮＡ的各组中均检测有ＨＦＲＳＶ－ＲＮＡ。结果表明ＮｅｓｔｅｄＲＴ－ＰＣＲ具有高特异、高敏感的特点,可用于检测恙螨体内微量ＨＦＲＳＶ－ＲＮＡ,为确认恙螨作为ＨＦＲＳＶ的传播媒介提供了分子生物学证据。     

南方液压公司"供应商管理库存"设计与实施

供应商管理库存(VMI)是一种在用户和供应商之间的合作性策略。通过策略选择、实施目标分析及协议制定三个角度分析研究,设计实施的南方液压公司VMI模式全程方案,可有效提升南方液压公司的库存管理水平。     

服务型供应链收益共享契约研究

以供应链博弈理论为背景,研究上游企业向下游企业提供知识型产品的二级供应链协调问题,上游企业是斯塔博格博弈的领导者,下游企业是跟从者。上游企业需要在一系列的收费和成本分担的方式中选择一种使供应链系统高效运作的方式。通过研究发现:上游企业对下游企业生产的产品收取一定费用并对下游企业未售库存给予一定补贴能够使供应链协调并使自己的利润最大化。