Morphology,cytology and forage potential of Pennisetum americanum (L.) K. Schum. x P. Purpureum Schum. amphidiploids

Summary F₁ hybrids between short-day photoperiod- sensitive maiwa bulrush millet, Pennisetum americanum (2n=14), and elephant grass, P. purpureum (2n=28), are triploid (2n=21), sterile, and can only be propagated vegetatively. Fertile amphidiploids, (2n=42, with 21 bivalents) were produced by colchicine treatment. Good seed set was obtained upon selfing the amphidiploids and the progeny exhibited variable pollen fertility and bivalent univalent and multivalent formation.Reciprocal crosses between elephant grass and the colchicine-induced amphidiploid failed to produce seeds. The maiwa millet x amphidiploid cross resulted in poor seed set and the reciprocal failed. Maiwa x amphidiploid hybrids were pollen sterile with 2n=21, rather than the expected 2n=28, indicating chromosome elimination.Morphologically, the amphidiploids and maiwa x amphidiploid hybrids closely resembled elephant grass and the F₁ hybrid. The amphidiploids showed no superiority over the F₁ hybrid and elephant grass in either forage yield or quality but one maiwa x amphidiploid genotype surpassed a promising local elephant grass selection in forage dry matter yield and flowered for a relatively short period.     

miR-155-specific siRNA enhances chemosensitivity of Burkitt lymphoma Raji cells to cytosine arabinoside by inducing apoptosis

AIM：To investigate the effect of miR-155-specific siRNA alone or in combination with cytosine arabinoside (Ara-C) on the growth and apoptosis of Burkitt lymphoma Raji cells. METHODS：miR-155-specific siRNA and/or Ara-C were used to treat the cells. Quantitative real-time polymerase chain reaction was used to detect the expression of miR-155. The growth of the cells was analyzed by CKK-8 assay. The cell apoptosis was determined by flow cytometry. RESULTS：The miR-155 expression level of the cells transfected with miR-155 siRNA was significantly lower than that in the 2 control groups. Ara-C or miR-155 siRNA alone inhibited the growth of Raji cells in a dose-depend manner. miR-155 siRNA combined with Ara-C produced more inhibition of cell proliferation (P<0.05). After treatment for 48 h, the apoptotic rate of Raji cells in miR-155 siRNA+Ara-C group ［(38.4±1.4)%］ was higher than that in Ara-C group ［(16.5±0.3)%］ and miR-155 siRNA group ［(14.6±0.3)%］, with statistically significant difference (P<0.05). The expression of caspase-3 in Ara-C+miR-155 siRNA group was increased significantly as compared with Ara-C group and miR-155 siRNA group. CONCLUSION：miR-155-specific siRNA enhances the chemosensitivity of Raji cells to Ara-C by inducing apoptosis through the caspase-3 pathway.     

microRNA-155在长白猪和通城猪骨骼肌发育过程中的表达分析

本研究旨在分析miR-155在长白猪(瘦肉型)和通城猪(脂肪型)骨骼肌发育过程中的表达变化,以了解其在猪肌肉发育中的重要作用。选用长白猪和通城猪不同发育时期(胚胎期12个时期,出生后10个时期)骨骼肌为材料,利用Stem-Loop RT-PCR方法检测miR-155的表达变化。此外,本研究还分析了miR-155在成年通城猪各组织的表达。结果,miR-155在长白和通城猪骨骼肌发育过程中差异表达呈现不同的表达模式。在通城猪中,miR-155在小肠和肺中表达量较高,在心脏和胎盘中度表达,而在其他组织中表达较低。结果提示,miR-155可能参与猪肌细胞增殖和分化,从而影响猪骨骼肌发育,与猪肌肉的表型有关。     

四个小麦抗穗发芽分子抗性标记有效性的验证与评价

成熟期穗发芽是一种世界性灾害, 严重影响小麦品质和产量。本试验利用已报道的4个与穗发芽抗性相关的标记, 即STS标记MST101、STMS标记wmc104、QTL位点Xgwm155与Vp1B3, 结合穗发芽率分析,对95份中国小麦地方品种和历史品种的穗发芽抗性进行筛选, 旨在从中筛选出抗穗发芽品种, 并对这4个分子标记的有效性进行比较, 筛选出可用于种质资源筛选和分子标记辅助育种的高效分子标记。结果表明, Vp1B3和Xgwm155与穗发芽抗性相关, 而MST101和wmc104与穗发芽抗性无关。比较而言, Vp1B3更能有效地用于筛选穗发芽抗性品种, 但将Vp1B3和Xgwm155结合起来筛选抗穗发芽小麦品种, 会提高选择效率。     

普通小麦DH155抗白粉病基因的分子作图及应用分子标记辅助选择将其转移

普通小麦品系DH155对白粉病菌表现高抗。为明确DH155所携带抗白粉病基因的遗传方式及与抗病基因连锁SSR标记,利用DH155与高感小麦品系SN2890杂交获得的F2和F2:3群体进行接种鉴定和遗传分析,发现DH155对白粉菌菌株E09的抗性受1对显性基因控制,暂命名为Ml DH155。BSA和分子标记分析结果显示,Ml DH155与SSR标记Xcfd81和Xcfd18连锁。利用已发表的中国春和粗山羊草D基因组序列开发新标记,进一步将Ml DH155定位于标记Xsdau K525和Xsdau K527之间,其遗传距离分别为0.2 c M和0.8 c M。将DH155与感白粉病优良品系HB133-4和旱10杂交,在F2~F4代,结合优良农艺性状选择、分子标记辅助选择和抗白粉病鉴定,获得3个高抗白粉病且农艺性状优异的株系(SDAU2100、SDAU2101和SDAU2102)。利用14个白粉菌菌株对DH155进行苗期接种鉴定表明,DH155对13个菌株表现抗病反应型。这些菌株对DH155的毒力谱与已知抗白粉病基因Pm2相似,但DH155对Bg78-3和Bg44-5菌株的反应型与携带Pm2的Ulka/8*Cc不同。结合本试验结果和Pm2基因的相关报道,推测Ml DH155可能是Pm2或其等位基因。     

Changes of miR-155-5p in serum of cervical cancer patients and effects of miR-155-5p on cervical cancer cells

AIM:To detect the serum level of miR-155-5p in the patients with different cervical diseases, and to analyze its effects on the proliferation, cell cycle and apoptosis of cervical cancer cells. METHODS:SYBR Green I real-time quantitative PCR was used to detect the level of miR-155-5p in the serum of the patients with different cervical diseases. miR-155-5p mimic or inhibitor was used to increase or decrease the expression of miR-155-5p in cervical cancer cells. The proliferation, cell cycle and apoptosis were measured by CCK-8 assay and flow cytometry. RESULTS:The serum level of miR-155-5p in cervical cancer group was higher than that in cervicitis group and healthy group. No statistical difference of the serum miR-155-5p level between cervical intraepithelial neoplasia group and cervical cancer group was observed. Compared with blank group, liposome group and negative control group, the proportion of S-phase cells increased and apoptotic cells decreased in SiHa cells transfected with 100 nmol/L and 200 nmol/L miR-155-5p mimic. The proportion of G2/M-phase cells increased significantly in SiHa cells transfected with 100 nmol/L and 200 nmol/L miR-155-5p inhibitor. CONCLUSION: Compared with healthy controls, the serum level of miR-155-5p in the cervical cancer patients increases, and may act as a novel tumor molecular marker for diagnosis of cervical cancer. miR-155-5p has no significant effect on the proliferation, cell cycle and apoptosis of HeLa cell. miR-155-5p may promote SiHa cells to enter S phase and inhibit the apoptosis of SiHa cells.     

Evaluation of the systemic activity of simeconazole in comparison with that of other DMI fungicides

The systemic activity of simeconazole (RS-2-(4-fluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-trimethylsilylpropan-2-ol) in plants was compared with those of eight other sterol demethylation inhibitor (DMI) fungicides. Simeconazole prevented the infection of Blumeria graminis (DC) Speer f sp hordei Marchal on barley leaves within a radius of several centimeters from the edge of local treatment on the leaves when the compound was separated from the leaves by glass coverslips. This reveals that simeconazole has prominent vapour-phase activity. Simeconazole showed excellent curative activity against barley powdery mildew when treated 1-3 days after inoculation. Furthermore, this indicates that simeconazole has notable translaminar activity because, when the compound was applied onto either the adaxial or abaxial leaf surface, it showed excellent efficacy against powdery mildew on the opposite side of the leaf surface of barley and cucumber. Simeconazole also showed excellent efficacy against barley powdery mildew by soil drench 24h after inoculation. This suggests that simeconazole was absorbed very quickly into the barley plant after treatment. The permeability of the compound through cuticular membranes prepared from tomato fruits was about 20% at 22 h after the treatment and was much superior to that of the other DMI fungicides tested.     

MiR-155靶向踝蛋白调控柱状黄杆菌胞外多糖诱导的EPC细胞凋亡

柱状黄杆菌胞外多糖 (FC-EPS) 孵育能显著提高鲤上皮瘤细胞 (EPC) 中 miR-155 的表达,导致细胞发生凋亡。为研究 miR-155 在 FC-EPS 诱导的细胞凋亡中的作用机制,本文采用 RNAi 技术,通过过表达 miR-155 和敲降踝蛋白 (talin-1),皆能抑制 FC-EPS 诱导的细胞凋亡,并鉴定出 talin-1 为 miR-155 的靶蛋白。在 FC-EPS 诱导细胞凋亡的过程中,踝蛋白水平显著升高,在凋亡发生阶段检测到凋亡执行蛋白 caspase-3 的活化,同时检测到两条踝蛋白剪切异构体,大小约为200 kDa 和 250 kDa;将构建的鲤 talin-1 真核表达质粒转染 EPC 细胞,过表达的 talin-1 延迟且延长了细胞凋亡的进程,并检测到上述两条踝蛋白异构体。然而,当以 FC-EPS 转染 EPC 细胞时,talin-1 先下降再恢复到正常水平,细胞不发生凋亡。因此,在 FC-EPS 诱导细胞凋亡的过程中,细胞通过上调 miR-155 来调控靶基因 talin-1 mRNA 和蛋白转录的变化,以及产生 talin-1 蛋白异构体来抑制细胞发生凋亡。本文为有效防治柱状黄杆菌疾病提供新思路。     

板栗疫病菌低毒力遗传转化株LC的构建

低毒病毒—板栗疫病菌组合是研究病毒—宿主相互作用的模式系统之一。通过构建含板栗疫病菌低毒病毒CHV1-EP713的全长cDNA和苯菌灵抗性基因的表达质粒pXB3F2,并用于转化野生型无毒株EP155,获得了以苯菌灵抗性为筛选标记、具有dsRNA病毒再生能力的低毒力遗传转化株LC,为深入研究病毒—真核宿主相互作用的分子机制提供了新的研究材料。     

Expression and significance of T-cell immunoglobulin and ITIM domain in colorectal cancer

AIM: To study the expression and clinical significance of T-cell immunoglobulin and ITIM domain (TIGIT) in colorectal cancer. METHODS: The patients with colorectal cancer (n=80) from January 2016 to June 2018 were selected. The expression of TIGIT and CD155 in the colorectal cancer tissues and adjacent normal tissues were detected by immunohistochemical staining method. The expression of TIGIT and CD155 was also determined by Western blot and ELISA. RESULTS: The positive expression rates of TIGIT and CD155 were 78.8% (63/80) and 83.8% (67/80) in the colorectal cancer tissues, significantly higher than that in the paracancerous tissues of 8.8% (7/80) and 18.8% (15/80), respectively (P<0.05). There was a positive correlation between TIGIT and CD155 expression (r=0.867, P<0.01). The expression levels of TIGIT and CD155 were increased as the stage evolved. The positive rates of TIGIT and CD155 in the colorectal cancer tissues were correlated with the degree of differentiation, pathological stage and lymph node metastasis (P<0.05). CONCLUSION: TIGIT and CD155 are correlated with the occurrence and development of colorectal cancer, and can be used as one of the prognostic indicators of colorectal cancer.