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51.
Animal cloning can be achieved by somatic cell nuclear transfer(SCNT), but the resulting live birth rate is relatively low. We previously improved the efficiency of bovine SCNT by exogenous melatonin treatment or by overexpression of lysine-specific demethylase 4D(KDM4D) and 4E(KDM4E). In this study, we revealed abundant alternative splicing(AS) transitions during fertilization and embryonic genome activation, and demonstrated abnormal AS in bovine SCNT embryos compared with in vitro fertilized ...  相似文献   
52.

Background

Cotton fibers (produced by Gossypium species) are the premier natural fibers for textile production. The two tetraploid species, G. barbadense (Gb) and G. hirsutum (Gh), differ significantly in their fiber properties, the former having much longer, finer and stronger fibers that are highly prized. A better understanding of the genetics and underlying biological causes of these differences will aid further improvement of cotton quality through breeding and biotechnology. We evaluated an inter-specific Gh × Gb recombinant inbred line (RIL) population for fiber characteristics in 11 independent experiments under field and glasshouse conditions. Sites were located on 4 continents and 5 countries and some locations were analyzed over multiple years.

Results

The RIL population displayed a large variability for all major fiber traits. QTL analyses were performed on a per-site basis by composite interval mapping. Among the 651 putative QTLs (LOD > 2), 167 had a LOD exceeding permutation based thresholds. Coincidence in QTL location across data sets was assessed for the fiber trait categories strength, elongation, length, length uniformity, fineness/maturity, and color. A meta-analysis of more than a thousand putative QTLs was conducted with MetaQTL software to integrate QTL data from the RIL and 3 backcross populations (from the same parents) and to compare them with the literature. Although the global level of congruence across experiments and populations was generally moderate, the QTL clustering was possible for 30 trait x chromosome combinations (5 traits in 19 different chromosomes) where an effective co-localization of unidirectional (similar sign of additivity) QTLs from at least 5 different data sets was observed. Most consistent meta-clusters were identified for fiber color on chromosomes c6, c8 and c25, fineness on c15, and fiber length on c3.

Conclusions

Meta-analysis provided a reliable means of integrating phenotypic and genetic mapping data across multiple populations and environments for complex fiber traits. The consistent chromosomal regions contributing to fiber quality traits constitute good candidates for the further dissection of the genetic and genomic factors underlying important fiber characteristics, and for marker-assisted selection.  相似文献   
53.
A rapid, sensitive and simple high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method was developed for determination of cefazedone in human plasma using metronidazole as internal standard (IS). The chromatographic separation was achieved on an Ultimate XB-CN column (2.1 mm × 150 mm, 5 μm) with an isocratic mobile phase of acetonitrile and 20 mM ammonium acetate in 0.1% formic acid in water (15:85, v/v). Detection was performed using electrospray ionization in positive ion multiple reaction-monitoring mode (SRM), monitoring the transitions m/z 548.2 → 344.1 for cefazedone and m/z 172.2 → 128.1 for IS. Calibration curves were linear over a wide range of 0.20–401.12 μg/mL for cefazedone in plasma. The lower limit of quantification (LLOQ) was 0.20 μg/mL. The intra- and inter-day precisions were less than 7.2%. The average recovery of cefazedone was 90.8–91.0%. The validated method was successfully applied to the pharmacokinetic study of cefazedone in Chinese healthy volunteers following intravenous (IV) administration of 500, 1000 and 2000 mg cefazedone injection.  相似文献   
54.
The properties of equilibria and phase synchronization involving burst synchronization and spike synchronization of two electrically coupled HR neurons are studied in this paper. The findings reveal that in the non-delayed system the existence of equilibria can be turned into intersection of two odd functions, and two types of equilibria with symmetry and non-symmetry can be found. With the stability and bifurcation analysis, the bifurcations of equilibria are investigated. For the delayed system, the equilibria remain unchanged. However, the Hopf bifurcation point is drastically affected by time delay. For the phase synchronization, we focus on the synchronization transition from burst synchronization to spike synchronization in the non-delayed system and the effect of coupling strength and time delay on spike synchronization in delayed system. In addition, corresponding firing rhythms and spike synchronized regions are obtained in the two parameters plane. The results allow us to better understand the properties of equilibria, multi-time-scale properties of synchronization and temporal encoding scheme in neuronal systems.  相似文献   
55.
Jin Z  Guo HS  Xu DY  Hong MY  Li XL  Xu WX 《生理学报》2004,56(6):678-684
为探讨非肾上腺素能非胆碱能神经递质对胃窦环行肌功能的调节作用,在离体胃平滑肌上观察了嘌呤拟似物对胃窦环行肌自发性收缩活动和电活动的影响。电活动用传统的细胞内微电极记录,并和收缩活动同步描记于多道生理记录仪。结果表明,嘌呤能P2Y受体激动剂,三磷酸腺苷(ATP)和2-methylthio ATP(2-MeSATP)均增强胃窦平滑肌的收缩活动,但不影响电活动,而且ATP和2-MeSATP对胃平滑肌收缩活动的增强作用可被嘌呤能P2Y受体阻断剂,reactive blue-2和苏拉明(suramin)所阻断。用100μmol/L α,β-MeATP引起的脱敏感使P2X受体被阻断,ATP增强胃窦平滑肌收缩活动的效应不受影响。嘌呤能P2X受体激动剂,α,β-MeATP明显抑制胃窦环行肌自发性收缩活动,同时使膜电位明显超极化。ATP对胃窦平滑肌的收缩作用不被L型钙通道阻断剂尼卡地平(nicardipine)阻断,但细胞外用无钙液灌流时这种效应则完全被阻断。用前列腺素合成抑制剂消炎痛预先处理20min后,ATP和2-MeSATP仍能增强胃窦平滑肌的自发性收缩活动。以上结果提示:(1)ATP和2-MeSATP通过嘌呤能P2Y受体增强胃窦平滑肌的自发性收缩活动,而α,β-MeATP或β,γ-MeATP通过嘌呤能P2X受体使膜电位超极化,引起胃窦平滑肌的舒张;(2)ATP和2-MeSATP增强胃窦平滑肌自发性收缩活动的效应依赖于细胞外钙,但钙离子进入细胞的途径并不是电压依赖性钙通道;(3)ATP和2-MeSATP增强胃窦平滑肌自发性收缩活动的效应不通过前列腺素介导。  相似文献   
56.
Abstract In this paper, two new species of the genus Phytocoris Fallen ( Ph. nitrariae sp. nov., Ph. macer sp. nov.) are described from China. Both of these two species belong to the subgenus Sooso-capsus Wagner when Wagner's system (1970) is used.  相似文献   
57.
Ren Y  Li SR  Li J  Zhou Q  DU XY  Li TJ  Yang WY  Zheng YL 《遗传》2011,33(11):1263-1270
小麦条锈病是影响杂交小麦普及推广的重要因素。文章利用基因推导法和SSR分子标记技术,研究了温光型两系杂交小麦恢复系MR168的抗条锈性遗传规律及其控制基因染色体位置。结果表明,MR168对CY29、CY31、CY32、CY33等条锈菌生理小种表现高抗至免疫;对SY95-71/MR168杂交组合的正反交F1、BC1、F2和F3群体分单株接种鉴定显示,MR168对CY32号小种的抗性受1对显性核基因控制,该抗病基因来源于春小麦品种辽春10号。利用集群分离分析法(Bulked segregant analysis,BSA)和简单重复序列(Simple sequence repeat,SSR)分子标记分析抗病亲本MR168、感病亲本SY95-71及183个F2代单株,发现了与MR168抗条锈病基因连锁的5个微卫星标记Xgwm273、Xgwm18、Xbarc187、Xwmc269、Xwmc406,并将该基因初步定位在1BS着丝粒附近,暂命名为YrMR168;构建了包含YrMR168的SSR标记遗传图谱,距离YrMR168最近的两个微卫星位点是Xgwm18和Xbarc187,遗传距离分别为1.9 cM和2.4 cM,这两个微卫星标记可用于杂交小麦抗条锈病分子标记辅助育种。  相似文献   
58.
福建含笑属一新种   总被引:1,自引:0,他引:1  
郑清芳 《植物研究》1981,1(3):92-94
常绿乔木,高达15米,胸径40厘米,树皮灰褐色,小枝、芽、叶柄及果梗密被黄棕色绒毛。叶薄革质,长圆形或窄倒卵状椭圆形,长6-11厘米,宽2.5-4厘米,顶端尖,基部圆形,上面中脉残留有短绒毛,下面密被锈红色或淡棕黄色平伏绢毛,侧脉每边8-9条,网脉稠密,在两面均凸起,叶柄无托叶痕,长1-1.5厘米。  相似文献   
59.
Leptin对猪原代脂肪细胞脂解及其关键脂酶mRNA表达的影响   总被引:3,自引:0,他引:3  
Leptin是由脂肪组织分泌的内源因子,在调节机体能量平衡过程中起重要作用.Leptin促进脂解的研究由来已久,但其作用机理尚不完善.本研究旨在通过系统检测关键脂酶mRNA的表达变化来探讨Leptin促进脂解的分子机理.运用形态学观察,油红O染色和RT-PCR鉴定培养的猪原代脂肪细胞;甘油测定试剂盒和游离脂肪酸(FFA)测定试剂盒分别检测甘油和FFA的释放;半定量RT-PCR检测关键脂酶mRNA的表达.结果显示:100 nmol/L的Leptin可显著上调ATGL、TGH-2、HSL、MGL和LPL mRNA的表达(P<0.01),但同时下调Perilipin mRNA的表达(P<0.01);Leptin呈浓度依赖性促进甘油的释放(P<0.01),但对FFA的释放影响不显著(P>0.05).以上结果提示,Leptin可能主要通过上调ATGL、MGL、LPL和下调Perilipin的表达促进猪原代脂肪细胞的脂解;同时推测,FFA释放的相对稳定可能是由Leptin通过上调UCPs的表达而增加FFA的消耗引起的.  相似文献   
60.
Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death worldwide. In China, the situation is even worse as cancer incidence and mortality continue to increase rapidly. Although tremendous progress has been made toward HCC treatments, the benefits for liver cancer patients are still limited. Therefore, it is necessary to identify and develop novel therapeutic methods. Neuronally expressed developmentally downregulated 4 (NEDD4), an E3 ubiquitin ligase, plays a critical role in the development and progression of various types of human cancers. In our study, NEDD4 acts as an oncoprotein in both QGY7703 and SMMC7721 liver cancer cell lines. We found that depletion of NEDD4 by siRNA transfection led to inhibition of cell growth, invasion and migration, and promotion of apoptosis. In contrast, overexpression of NEDD4 via plasmid transfection resulted in facilitated cell proliferation, invasion and migration, and decreased apoptosis. Importantly, we observed that tumor suppressor LATS1, also a core component of Hippo pathway, was negatively regulated by NEDD4 in liver cancer cells. Our findings suggested that NEDD4 may be involved in the HCC progression via regulating LATS1 associated signaling pathway. Therefore, targeting NEDD4-LATS1 signaling could be a potential therapeutic option for HCC treatment.  相似文献   
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