硒对心肌质膜(Ca~(2+)·Mg~(2+))-ATPase和肌浆网Ca~(2+)-ATPase活力的影响

本文以豚鼠和大白鼠心肌肌浆网膜(SR)Ca~(2+)-ATPase的活力,心肌质膜(SL)(Ca~(2+)Mg~(2+))-ATPase的活力和电子显微镜的方法探索克山病病区粮中低硒与心肌细胞钙转运调控的共系,实验结果为硒对克山病有预防作用的观点提供了新的理论依据,并进一步支持了“克山病是一种心肌线粒体病”的观点。     

Development of A Super-Sensitive Diagnostic Method for African Swine Fever Using CRISPR Techniques

African swine fever(ASF) is an infectious disease caused by African swine fever virus(ASFV) with clinical symptoms of high fever, hemorrhages and high mortality rate, posing a threat to the global swine industry and food security. Quarantine and control of ASFV is crucial for preventing swine industry from ASFV infection. In this study, a recombinase polymerase amplification(RPA)-CRISPR-based nucleic acid detection method was developed for diagnosing ASF. As a highly sensitive method, RPA-CRISPR can detect even a single copy of ASFV plasmid and genomic DNA by determining fluorescence signal induced by collateral cleavage of CRISPR-lwCas13 a(previously known as C2 c2) through quantitative real-time PCR(qPCR) and has the same or even higher sensitivity than the traditional qPCR method. A lateral flow strip was developed and used in combination with RPA-CRISPR for ASFV detection with the same level of sensitivity of TaqMan qPCR. Likewise, RPA-CRISPR is capable of distinguishing ASFV genomic DNA from viral DNA/RNA of other porcine viruses without any cross-reactivity. This diagnostic method is also available for diagnosing ASFV clinical DNA samples with coincidence rate of 100% for both ASFV positive and negative samples. RPA-CRISPR has great potential for clinical quarantine of ASFV in swine industry and food security.     

小麦赤霉病菌对多菌灵的抗药性与α2-微管蛋白序列无关析

[目的]研究小麦赤霉病菌对多菌灵的抗药性与α2-微管蛋白基因的相关性.[方法]比较对多菌灵不同敏感性水平菌株间在药剂作用下的形态学特征及其α2-微管蛋白基因异同.[结果]当敏感菌株和田间中抗菌株均在各自EC50和EC90浓度作用下,两者分生孢子芽管和初生菌丝均表现畸形,肿胀,分支增多.根据小麦赤霉病菌核基因组测序菌株NRRL31 084(PH-1)的α2-微管蛋白基因核苷酸序列设计4对引物,采用PCR方法克隆并测定了小麦赤霉病菌(Fusarium graminearum)对多菌灵(MBC)不同敏感性表型的8个中国菌株的α2-微管蛋白基因全序列.DNA序列比对结果表明中国的4个敏感菌株和4个抗药性菌株的α2-微管蛋白基因核苷酸序列同源性没有差异,多菌灵抗药性与α2-微管蛋白无关.该基因全长1712 bp,含有4个内元,编码453 aa;与NRRL31 084的α2-微管蛋白基因核苷酸序列同源性为99%,存在5个差异核苷酸,与其所编码的氨基酸序列同源性为100%;与其他9种真菌α2-微管蛋白基因所编码的氨基酸序列同源性为64%～89%.[结论]小麦赤霉病菌对多菌灵的抗药性与α2-微管蛋白序列无关.     

广东、海南两省小皮伞属的种类

本文报道广东省和海南省的小皮伞属Marasmius Fr,的种类46种,其中有1个新种和12个国内新记录种。新种为海南小皮伞Marasmius hainanensis T.H.Li sp nov.。文中列有上述种类的分种检索表和新种的中文和拉丁文描述。     

粤北小皮伞属的种类记述

本文报道了作者1984—1985年自广东北部山区所采集有关小皮伞属16个种,其中1个新种:Marasmius australis Bi et Li,sp.nov,以及11个国内新纪录。并附分种检索表。     

黄瓜种子及其萌发期的化感作用研究

以大白菜、萝卜、番茄和黄瓜种子为受体,采用实验室培养皿种子发芽生物测试法研究了黄瓜种子浸提液、种子萌发、胚根和芽苗分泌物、芽苗腐解物和芽苗浸提液的化感效应。结果表明:(1)黄瓜种子浸提液对大白菜、萝卜、番茄和黄瓜种子萌发均有化感抑制作用,即黄瓜种子内含有某些化感抑制物质。(2)在水浸提过的黄瓜种子萌发过程中,它不仅对其近邻套种的大白菜、萝卜和番茄种子萌发产生化感抑制作用,而且其胚根和芽苗分泌物对后茬播种的4种蔬菜种子发芽也表现出不同程度的化感抑制作用;黄瓜芽苗腐解物和芽苗水浸提液也对各受体蔬菜种子发芽与生长产生不同程度的化感抑制作用,且随着腐解芽苗量的增加或浸提液浓度的升高,各受体蔬菜种子的发芽指标值、化感效应指数值和综合效应值随之降低。(3)黄瓜种子浸提液及芽苗各器官的化感物质对黄瓜种子的萌发与生长产生了自毒作用,且黄瓜芽苗腐解物、芽苗浸提液、胚根及芽苗分泌物对受体黄瓜的自毒作用均为最大。研究发现,黄瓜种子浸提液、种子萌发时期以及芽苗各器官的化感物质主要是通过抑制受体胚根的生长而起化感抑制作用,即受体蔬菜种子胚根对化感效应最为敏感;因黄瓜种子及萌发期释放化感物质的途径有所不同,导致受体大白菜、萝卜、黄瓜和番茄的化感响应也不相同;在黄瓜种子萌发和芽苗生长的早期,化感物质即开始在芽苗体内进行合成与积累,一部分可通过胚根和芽苗分泌途径释放到环境中,另一部分可通过芽苗腐解途径释放化感物质,并对受体蔬菜种子萌发与生长表现出较强的化感抑制作用。     

Nobiletin suppresses cholangiocarcinoma proliferation via inhibiting GSK3β

Background: Cholangiocarcinoma (CCA) is a type of hepatobiliary cancer characterized by uncontrolled cell proliferation, with a poor prognosis and high mortality. Nobiletin (NBT) is a promising anti-tumor compound derived from the peels of oranges and other citrus plants, citrus plant. But the effect of NBT on CCA remains unknown.Results: Our data showed that NBT suppressed CCA cell proliferation in vitro and in vivo. Colony formation and Edu assay indicated that NBT inhibited cell proliferation. Cell cycle analysis showed that NBT arrested the cell cycle in G0/G1 phase. Target prediction showed that GSK3β was a direct target. Western blot and immunofluorescence confirmed that NBT reduced the phosphorylation of GSK3β. The antiproliferative effect of NBT was intercepted in GSK3β knockdown CCA cells. The cellular thermal shift assay (CETSA) showed NBT directly bound to GSK3β. Finally, NBT showed an anti-proliferative effect in tumor-bearing mice with no hepatotoxicity.Conclusion: NBT could inhibit CCA proliferation, and the pharmacological activity of NBT in CCA was attributed to its direct binding to GSK3β. We suggested that NBT might be a potential natural medicine in CCA treatment.     

UVB irradiation-induced dysregulation of plasma membrane calcium ATPase1 and intracellular calcium homeostasis in human lens epithelial cells

Ultraviolet B (UVB) could lead to the apoptosis of human lens epithelial cell and be hypothesized to be one of the important factors of cataractogenesis. In the human lens, Ca²⁺-ATPase is a major determinant of calcium homeostasis. Plasma membrane calcium ATPase1 (PMCA1) is a putative “housekeeping” isoform and is widely expressed in all tissues and cells, which plays an important role in calcium homeostasis. However, the effects of UVB-irradiation on the expression of PMCA1 and the cellular calcium homeostasis are still unclear. In the present study, we cultured human lens epithelial cells (HLE B-3) in vitro and investigated the effects of UVB irradiation on the expression of PMCA1 and the intracellular calcium homeostasis using real-time cell electronic sensing system, flow cytometry, fluo-3/AM probes, real-time quantitative PCR, and enzyme-linked immunosorbent assay techniques. We found that UVB irradiation could induce human lens epithelial cell death, cause intracellular calcium ion (Ca²⁺) elevation, inhibit Ca²⁺-ATPase activity and decrease the expression of PMCA1 at gene and protein levels, suggesting that the downregulation of PMCA1 and the disruption of calcium homeostasis may play important roles in UVB-induced HLE B-3 cell apoptosis.