Construction of a cucumber genetic linkage map with SRAP markers and location of the genes for lateral branch traits

Cucumber (Cucumis sativus L. 2n = 2x = 14), thatbelongs to Cucurbitaceae family, is one of majorvegetables with a planting area second to that of to-mato in the world[1]. Due to its economical importanceplant breeders and geneticists have paid much atten-tion to the genetic study on this important vegetablecrop, but the research progress in cucumber is muchless than that in tomato. In 1990, Pierce[2] reviewed allthe reported genes of cucumber that had been geneti-cally analyzed since the 1930…     

Cloned pig fetuses exhibit fatty acid deficiency from impaired placental transport

Cloned pig fetuses produced by somatic cell nuclear transfer show a high incidence of erroneous development in the uteri of surrogate mothers. The mechanisms underlying the abnormal intrauterine development of cloned pig fetuses are poorly understood. This study aimed to explore the potential causes of the aberrant development of cloned pig fetuses. The levels of numerous fatty acids in allantoic ?uid and muscle tissue were lower in cloned pig fetuses than in artificial insemination‐generated pig fetuses, thereby suggesting that cloned pig fetuses underwent fatty acid deficiency. Cloned pig fetuses also displayed trophoblast hypoplasia and a reduced expression of placental fatty acid transport protein 4 (FATP4), which is the predominant FATP family member expressed in porcine placentas. This result suggested that the placental fatty acid transport functions were impaired in cloned pig fetuses, possibly causing fatty acid deficiency in cloned pig fetuses. The present study provides useful information in elucidating the mechanisms underlying the abnormal development of cloned pig fetuses.     

长春花主要农艺性状与文多灵含量的相关及通径分析

文多灵(vindoline)具有重要的药用价值。本文利用反相高效液相色谱法检测了23种国内外长春花主栽品种的文多灵含量, 对文多灵含量与品种的12个主要农艺性状(包括株高、节间距、茎直径、一级侧枝数、叶片长、叶片宽、叶片长宽比、百片叶重、全株叶片重、花瓣直径、种荚长度和种子数/荚)的相关性和通径进行了分析。相关性分析表明, 文多灵含量与一级侧枝数、茎直径、节间距、叶片宽、株高、全株叶片重、百片叶重、花瓣直径和叶片长呈正相关, 其中与一级侧枝数和茎直径的相关性达到显著水平(P<0.05), 与节间距的相关性接近显著水平; 与叶片长宽比、种荚长度和种子数/荚呈负相关。通径分析结果表明, 长春花的主要农艺性状中, 节间距、一级侧枝数和全株叶片重对文多灵含量的正影响达到了显著水平(P<0.05),通径系数分别为0.959、0.716和.431, 说明节间距、一级侧枝数和全株叶片重可以作为高含量文多灵长春花品种选育的重要参考指标。     

长春花主要农艺性状与文多灵含量的相关及通径分析

文多灵(vindoline)具有重要的药用价值.本文利用反相高效液相色谱法检测了23种国内外长春花主栽品种的文多灵含量,对文多灵含量与品种的12个主要农艺性状(包括株高、节间距、茎直径、一级侧枝数、叶片长、叶片宽、叶片长宽比、百片叶重、全株叶片重、花瓣直径、种荚长度和种子数,荚)的相关性和通径进行了分析.相关性分析表明,文多灵含量与一级侧枝数、茎直径、节间距、叶片宽、株高、全株叶片重、百片叶重、花瓣直径和叶片长呈正相关,其中与一级侧枝数和茎直径的相关性达到显著水平(P<0.05),与节间距的相关性接近显著水平:与叶片长宽比、种荚长度和种子数/荚呈负相关.通径分析结果表明,长春花的主要农艺性状中,节间距、一级侧枝数和全株叶片重对文多灵含量的正影响达到了显著水平(P<0.05),通径系数分别为0.959、0.716和0.431,说明节间距、一级侧枝数和全株叶片重可以作为高含量文多灵长春花品种选育的重要参考指标.     

High-resolution mapping of the dull fruit skin gene D in cucumber (Cucumis sativus L.)

Dull/glossy fruit skin is a highly valuable external quality trait that affects the market value of cucumbers. In this study, genetic analysis showed that one single dominant gene, D (dull fruit skin), determines the dull fruit skin trait in cucumber. By combining bulked segregant analysis with 11 published polymorphic molecular markers on chromosome 5, the D/d gene was preliminarily mapped between markers SCZ69 and SSR16203, at genetic distances of 0.3 and 0.6 cM, respectively. Subsequently, a larger F2 (S06 × S94) population (842 individuals in total) was used for high-resolution mapping of the D/d gene. Finally, the D/d gene was fine-mapped between markers SSR37 and SSR112, at a physical distance of 244.9 kb (containing 31 candidate genes), using eight newly developed polymorphic simple sequence repeat (SSR) markers between SCZ69 and SSR16203. Based on semi-quantitative RT-PCR analysis, the possible candidate gene D was identified as Csa016880 or Csa016887. Meanwhile, validity analysis of the markers SSR37 and SSR112 was performed with 72 dull/glossy fruit lines, and showed that the two co-dominant SSR markers could be used for marker-assisted selection of the dull/glossy fruit trait in cucumber breeding. Moreover, this study will be helpful for cloning of the D gene in cucumber.     

Efficient deletion of LoxP-flanked selectable marker genes from the genome of transgenic pigs by an engineered Cre recombinase

Genetically modified (GM) pigs hold great promises for pig genetic improvement, human health and life science. When GM pigs are produced, selectable marker genes (SMGs) are usually introduced into their genomes for host cell or animal recognition. However, the SMGs that remain in GM pigs might have multiple side effects. To avoid the possible side effects caused by the SMGs, they should be removed from the genome of GM pigs before their commercialization. The Cre recombinase is commonly used to delete the LoxP sites-flanked SMGs from the genome of GM animals. Although SMG-free GM pigs have been generated by Cre-mediated recombination, more efficient and cost-effective approaches are essential for the commercialization of SMG-free GM pigs. In this article we describe the production of a recombinant Cre protein containing a cell-penetrating and a nuclear localization signal peptide in one construct. This engineered Cre enzyme can efficiently excise the LoxP-flanked SMGs in cultured fibroblasts isolated from a transgenic pig, which then can be used as nuclear donor cells to generate live SMG-free GM pigs harboring a desired transgene by somatic cell nuclear transfer. This study describes an efficient and far-less costly method for production of SMG-free GM pigs.

     

Tyro3, Axl,and Mertk receptors differentially participate in platelet activation and thrombus formation

Background

Previously, several studies have shown that Tyro3, Axl, and Mertk (TAM) receptors participate in platelet activation and thrombosis. However, the role of individual receptors is not fully understood.

Methods

Using single receptor-deficient platelets from TAM knockout mice in the C57BL/6?J strain, we performed a knockout study using single TAM-deficient mice. We treated platelets isolated from TAM knockout mice with the Glycoprotein VI (GPVI) agonists convulxin, poly(PHG), and collagen-related triple-helical peptide (CRP), as well as thrombin for in-vitro experiments. We used a laser-induced cremaster arterial injury model for thrombosis experiments in vivo.

Results

Deficiency of the tyrosine kinase receptors, Axl or Tyro3, but not Mertk, inhibited aggregation, spreading, JON/A binding, and P-selectin expression of platelets in vitro. In vivo, platelet thrombus formation was significantly decreased in Axl^?/? and Tyro3^?/? mice, but not in Mertk^?/? mice. Upon stimulation with glycoprotein VI (GPVI) agonists, tyrosine phosphorylation of signaling molecules, including spleen tyrosine kinase (Syk) and phospholipase C-γ2 (PLCγ2), was decreased in Axl^?/? and Tyro3^?/? platelets, but not in Mertk^?/? platelets. While platelet aggregation induced by agonists did not differ in the presence or absence of the Gas6 neutralizing antibody, the platelet aggregation was inhibited by anti-Axl or anti-Tyro3 neutralizing antibodies antibody, but not the anti-Mertk antibody. Additionally, the recombinant extracellular domain of Axl or Tyro3, but not that of Mertk, also inhibited platelet aggregation.

Conclusions

These data suggest that Axl and Tyro3, but not Mertk, have an important role in platelet activation and thrombus formation, and mechanistically may do so by a pathway that regulates inside to outside signaling and heterotypic interactions via the extracellular domains of TAMs.

     

Functional non-homologous end joining patterns triggered by CRISPR/Cas9 in human cells

正CRISPR/Cas9-mediated genome engineering technologies are now widely applied in various organisms,including mouse and human cells(Cong et al.,2013;Mali et al.,2013;Yang et al.,2013;Hsu et al.,2014).The most widely used customized CRISPR/Cas9(Sp Cas9)is derived from Streptococcus pyogenes(Cong et al.,2013).The CRISPR/Cas9 system creates site-specific double-     

奶牛粪酸臭成分降解过程中的微生物群落变化

【目的】研究可降解成年泌乳奶牛粪中主要酸臭物的微生物群落的组成及动态变化。【方法】利用牛粪堆肥环境中的微生物进行了发酵优化、菌种驯化以及酸臭有机物降解规律的研究,结合r DNA高通量测序技术对有益微生物的组成及相对生物量进行了分析。【结果】实验发现,奶牛排泄物中的臭味来源主要为短链有机酸,堆肥自然环境中的微生物可以有效地对有机酸等污染物进行去除,经从低到高浓度的有机酸臭物(W/V,0.1%–0.2%)驯化发酵后,培养物中原核微生物以芽孢杆菌居多,而真核微生物主要由红曲霉及粉状毕赤酵母组成。【结论】进一步推测这几种微生物是耐受并降解有机酸臭物的优势微生物,可以应用于奶牛养殖过程中酸臭排泄物的生物控制。