Bmo-miR-3351 modulates glutathione content and inhibits BmNPV proliferation by targeting BmGSTe6 in Bombyx mori

MicroRNAs(miRNAs)are small non-coding RNAs that play pivotal roles in the host response to invading pathogens.Among these pathogens,Bombyx mori nu-cleopolyhedrovirus(BmNPV)is one of the main causes of substantial economic losses in sericulture,and there are relatively few studies on the specific functions of miRNAs in the B.mori-BmNPV interaction.Therefore,we conducted transcriptome sequencing to identify differentially expressed(DE)messenger RNAs(mRNAs)and miRNAs in the midgut of 2 B.mori strains(BmNPV-susceptible strain P50 and BmNPV-resistant strain A35)after BmNPV infection.Through correlation analysis of the miRNA and mRNA data,we identified a comprehensive set of 21 miRNAs and 37 predicted target mRNAs.Notably,miR-3351,which has high expression in A35,exhibited remarkable efficacy in suppressing BmNPV proliferation.Additionally,we confirmed that miR-3351 binds to the 3'untranslated region(3'UTR)of B.mori glutathione S-transferase epsilon 6(BmG-STeo),resulting in its downregulation.Conversely,BmGSTe6 displayed an opposite expres-sion pattern to miR-3351,effectively promoting BmNPV proliferation.Notably,BmGSTe6 levels were positively correlated with glutathione S-transferase activity,consequently in-fluencing intracellular glutathione content in the infected samples.Furthermore,our in-vestigation revealed the protective role of glutathione against BmNPV infection in BmN cells.In summary,miR-3351 modulates glutathione content by downregulating BmGSTe6 to inhibit BmNPV proliferation in B.mori.Our findings enriched the research on the role of B.mori miRNAs in the defense against BmNPV infection,and suggests that the an-tiviral molecule,glutathione,offers a novel perspective on preventing viral infection in sericulture.

基于Mori-Tanaka方法的功能梯度厚壁圆筒近似热弹性理论解

【目的】功能梯度厚壁圆筒的热弹性问题存在不考虑组分材料微观结构影响,已有文献只给出了基于Mori-Tanaka方法功能梯度厚壁圆筒受力学和热学荷载的数值解,并且只考虑了球形夹杂这一单一夹杂形状的情形。【方法】基于Mori-Tanaka方法对功能梯度厚壁圆筒的热弹性问题进行分析,给出了一种近似热弹性理论解,该理论解不仅与数值解契合度高,而且可以考虑夹杂形状对物理量的影响,最后分析了不同边界条件下夹杂形状对径向位移和各向应力的影响。【结果】结果显示,在两种边界下,夹杂形状对径向位移都有较大的影响;但在温度边界下,夹杂形状对径向应力有较大影响,对轴向应力和周向应力影响较小;在应力边界下,夹杂形状对轴向应力影响较大,对周向应力和径向应力影响较小。

G-quadruplex is involved in the regulation of BmSGF1 expression in the Silkworm, Bombyx mori

Advanced DNA structures,such as the G-quadruplex(G4)and the i-motif,are widely but not randomly present in the genomes of many organisms.A G4 structure was identified in the promoter of the silk gland factor-1 gene(SGFI),which is the main regulatory gene for silk production in Bombyx mori.In this study,a BmSGF1 G4-/-ho-mozygous mutant was generated with the G4 sequence knocked out.The promoter activity of BmSGF1 was lowered in the BmSGF1 G4-/-mutant.Pyridostatin(PDS)stabilized the G4 structure and increased the promoter activity of BmSGF1,whereas anti-sense oligonu-cleotide(ASO)complementary to the G4 sequence suppressed the promoter activity of BmSGF1.Compared with wild-type larvae,the deletion of the BmSGF1 G4 structure de-creased both the expression of BmSGF1 and the fibroin heavy chain gene BmFib-H in the posterior silk gland and the weight of the cocoons.Overall,these results suggest that the promoter G4 structure of BmSGFI participates in the transcription regulation of the BmSGFl gene in the silkworm.

BmSLC7A5 is essential for silk protein synthesis and larval development in Bombyx mori

Insects produce silk to form cocoons,nests,and webs,which are important for their survival and reproduction.However,little is known about the molecular mecha-nism of silk protein synthesis at the translation level.The solute carrier family 7(SLC7)genes are involved in activating the target of rapamycin complex 1(TORC1)signaling pathway and protein translation process,but the physiological roles of SLC7 genes in silk-producing insects have not been reported.Here,we found that amino acid signaling regulates silk protein synthesis and larval development via the L-type amino acid trans-porter 1(LAT1;also known as SLC7A5)in Bombyx mori.A total of 12 SLC7 homologs were identified in the silkworm genome,among which BmSLC7A5 was found to be a silk gland-enriched gene and may be involved in leucine transport.Bioinformatics analy-sis indicated that SLC7A5 displays high homology and a close phylogenetic relationship in silk-producing insects.Subsequently,we found that leucine treatment significantly in-creased silk protein synthesis by improving the transcription and protein levels of silk genes.Furthermore,systemic and silk gland-specific knockout of BmSLC7A5 led to de-creased silk protein synthesis by inhibiting TORC1 signaling,and somatic mutation also resulted in arrested development from the 5th instar to the early pupal stage.Altogether,our study reveals that BmSLC7A5 is involved in regulating silk protein synthesis and larval development by affecting the TORC1 signaling pathway,which provides a new strategy and target for improving silk yield.

自洽法和Mori Tanaka法预测水泥浆体徐变的比较

为了预测水泥浆体的徐变性能,并对比不同预测模型的精度。使用微米压痕测试确定了水泥浆体的徐变模量,使用纳米压痕点阵测试获得微观物相的接触徐变模量。随后基于一系列微观测试获得物相的体积分数。将水泥浆体划分为2个尺度,分别基于自洽(self-consistent,SC)法和Mori Tanaka法,采用4种组合方式进行徐变均匀化预测。结果表明,在凝胶尺度采用Mori Tanaka法,在浆体尺度采用SC法时,水泥浆体的长期徐变性能的预测精度较高。该研究为进行水泥基材料徐变均匀化时选择合适的计算方法提供了依据。

Research progress on the effect of the combination of Jing acupoints bloodletting therapy and Sangzhi (Mori Ramulus) on shoulder-hand syndrome after stroke

Shoulder-hand syndrome(SHS)is one of the common complications of ischemic stroke.The pathogenesis is not completely clear and the therapeutic effects are not very satisfactory.As one of the Five-Shu acupoints(the general terms of acupoints that the twelve meridians are located below the elbow and knee of the body),Jing acupoints is distributed at the end of fingers and toes where the twelve meridians of the human body pass by,and has the functions of stimulating the meridians and dredging the channels and collaterals.For the effects of discharging neurons,promoting cerebral blood flow and improving the brain micro-circulation,Jing acupoints bloodletting therapy can effectively relieve the clinical symptoms of the patients with SHS after stroke.Sangzhi(Mori Ramulus),with the ability of dredging the meridian and relieving the pain,is also has certain treatment functions to the SHS.In clinical practice,the combination of Jing acupoints bloodletting and Sangzhi(Mori Ramulus)have been widely used in the treatment of various diseases,and in terms of their mechanism of action,the combined treatment has a positive effect on post-stroke SHS,but there are few reports on this.Therefore,it is worth affirming the efficacy of combined treatment of SHS after stroke.This article elaborates the theoretical basis of Jing acupoints bloodletting on SHS after stroke,and the research progress of Sangzhi(Mori Ramulus)in treating SHS after stroke,which provide the theoretical guidance for the combination.

Mori fructus aqueous extracts attenuates liver injury by inhibiting ferroptosis via the Nrf2 pathway

Background Liver fibrosis and hepatocellular carcinogenesis secondary to liver fibrosis are serious liver diseases with no effective treatments.Mori fructus aqueous extracts(MFAEs)have served as successful treatments for many types of liver injury including fibrosis although the molecular mechanisms are unknown at present.Purpose To investigate the effect of MFAEs in alleviating acute and chronic liver injury and tried to decipher the underlying mechanism.Methods and results Mice were divided into 5 groups(n ps:contro=8)for acute(groups:control,0.3%CCl_(4),bifendate(BD),100 and 200 mg/kg MFAEs,7 d)and chronic(groul,10%CCl_(4),BD,100 and 200 mg/kg MFAEs,4 weeks)liver injury study.Each mouse was injected intraperitoneally with 10μL/g corn oil containing CCl_(4)expect the control group.HepG2 cells were used in vitro study.Eighteen communal components were identified by UPLC-LTQOrbitrap-MS.We utilized a mouse model for acute and chronic liver injury using CCl_(4)and MFAEs administration effectively blocked fibrosis and significantly inhibited inflammation in the liver.MFAEs activated the nuclear factor erythroid derived 2 like 2/heme oxygenase 1(Nrf2/HO-1)pathway and promoted the synthesis of the antioxidants glutathione(GSH),superoxidedismutase(SOD)and glutathione peroxidase(GSH-Px)that resulted in reduced levels of CCl_(4)-induced oxidative stress molecules including reactive oxygen species.These extracts administered to mice also inhibited ferroptosis in the liver by regulating the expression of Acyl-CoA synthetase long chain family member 4(ACSL4),solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),thus reducing the occurrence of liver fibrosis.Both in vivo and in vitro tests indicated that the mechanism of MFAEs protection against liver fibrosis was linked to activation of Nrf2 signaling.These effects were blocked in vitro by the addition of a specific Nrf2 inhibitor.Conclusion MFAEs inhibited oxidative stress,ferroptosis and inflammation of the liver by activating Nrf2 signal pathway and provided a significant protective effect against CCl_(4)-induced liver fibrosis.

Expression Profiles and Response to Exogenous Hormones of β-Fructofuranosidase Gene BmSuc1 in Silkworms(Bombyx mori)

[Objectives]In order to clarify the regulatory effects of insect hormones on the expression of BmSuc1 and provide a reference for further analysis of the function and expression regulation mechanism of BmSuc1,this study explored the expression profiles of BmSuc1 in different tissues and periods of silkworm larvae and the expression changes of BmSuc1 after treatment with exogenous hormones.[Methods]By using the real-time fluorescence quantitative PCR technique,the expression characteristics of BmSuc1 were detected in different periods,different tissues and after treatment with exogenous hormones during the development of silkworm larvae.The expression of BmSuc1 and 20E receptor gene USP was detected after RNA interference with double-stranded RNA(dsRNA)of USP.[Results]The relative expression of BmSuc1 gene in the midgut was the highest,followed by the silk glands,epidermis and hemolymph.However,there was much lower or almost no expression in other tissues.In addition,the BmSuc1 expression profile exhibited a pulse-like pattern in silkworm larvae.The expression level of BmSuc1 was higher at each instar stage before molting,late fifth instar before cocooning and prepupal stage.Silkworm larvae at day 2 of the fifth instar were treated with 20-hydroxyecdysone(20E)and juvenile hormone(JH).It was found that the expression of BmSuc1 was extremely significantly higher at 12 and 18 h after 20E treatment than the control group injected with 0.1%dimethyl sulfoxide(DMSO)(P<0.01,the same below).But there were no significant difference in BmSuc1 expression between the JH treatment and the control group during the measurement time range(P>0.05).The dsRNA of USP was synthesized in vitro and injected into silkworm larvae at day 3 of the fifth instar.It was showed that the USP relative expression was extremely significantly down-regulated at 24 and 36 h after injection,which indicated that dsRNA interference was successful.RNAi of USP would block 20E signal transduction,and the expression of BmSuc1 was inhibited and significantly down-regulated at 24 and 36 h after injection of dsRNA of USP(P<0.05).[Conclusions]The BmSuc1 expression peaks appeared in the molting of silkworm larvae and the metamorphosis of larvae to pupae,which suggests that BmSuc1 may be involved in the metamorphic development process of silkworms.Treatment with exogenous ecdysone 20E can activate the expression of BmSuc1,but blocking the 20E signal transduction pathway may suppress expression of BmSuc1.It indicates that BmSuc1 as a downstream target gene in the 20E signal transduction pathway is directly or indirectly regulated by 20E signals.

人工饲料饲育家蚕5龄期的饲料效率研究

【目的】探明人工饲料饲育家蚕5龄期饲料效率与全龄桑叶育间的差异,为家蚕人工饲料的改进和饲育技术的优化提供技术支撑。【方法】以全龄桑叶育为对照(CK),研究家蚕5龄期不同饲育方式[1~5龄饲料育(5龄饲料育)、1~4龄饲料育5龄桑叶育(5龄桑叶育)]饲料效率间的差异。【结果】5龄饲料育家蚕第3天、第4天、第5天蚕体质量增量高于CK,第2天、第3天、第4天、第6天消化量低于CK,第2天、第3天、第4天、第5天体质转化率高于CK。5龄饲料育和5龄桑叶育的全茧转化效率、全茧生产效率、茧层转化效率和茧层生产效率均低于CK,5龄饲料育较CK分别低0.53百分点、0.10百分点、0.25百分点和0.08百分点,5龄桑叶育较CK分别低0.38百分点、0.14百分点、0.14百分点和0.06百分点;与5龄桑叶育相比,5龄饲料育除全茧生产效率高0.04百分点外,全茧转化效率、茧层转化效率、茧层生产效率分别低0.15百分点、0.11百分点和0.02百分点。【结论】全龄人工饲料育家蚕5龄期饲料效率低于全龄桑叶育,人工饲料饲育家蚕在饲料效率方面与全龄桑叶育有一定差距。

BmNPV侵染对家蚕β-N-乙酰葡萄糖苷酶活性及其相关基因转录水平的影响

为了深入解析β-N-乙酰葡萄糖苷酶(GlcNAcases)在病毒感染过程中的作用机制,将家蚕核型多角体病毒(BmNPV)经口感染5龄起家蚕,在感染后3、6、9、12、24 h提取家蚕血淋巴、脂肪体和中肠,采用荧光定量PCR方法检测GlcNAcases基因的表达水平,同时利用GlcNAcases测试盒测定GlcNAcases活性变化情况。结果显示,经口感染BmNPV后,家蚕血淋巴、脂肪体和中肠组织中GlcNAcases活性整体呈现先逐渐升高后急剧降低的趋势;而家蚕机体4个GlcNAcases编码基因的转录水平在不同组织中存在一定差异。在感染BmNPV后3~12 h,血淋巴中BmGlcNAcase1和BmGlcNAcase2的表达量均明显上调,BmGlcNAcase3和BmGlcNAcase4表达量与对照组(未感染)无差异;在感染后24 h,血淋巴中4个GlcNAcases基因表达量均开始下调,且表达量明显低于对照组。脂肪体组织中BmGlcNAcase2和BmGlcNAcase3在感染BmNPV后其表达量呈现先上调后下调的趋势,其中BmGlcNAcase2的表达量在感染BmNPV后3 h就开始上调,BmGlcNAcase3的表达量在9 h才开始上调,BmGlcNAcase1和BmGlcNAcase4的表达量无明显变化。感染BmNPV后,中肠BmGlcNAcase2和BmGlcNAcase4的表达量整体先逐渐上调,增高至一个峰值,随后急剧减弱,表达受到明显抑制;而BmGlcNAcase1和BmGlcNAcase3在感染BmNPV后其表达量呈现下调趋势,表达量逐渐降低。综上,BmGlcNAcase2编码的GlcNAcases在家蚕抵御BmNPV的侵染过程中发挥了一定的免疫防御功能。

亚致死剂量氰戊菊酯对家蚕生长发育的影响

采用浸叶法测定了氰戊菊酯对家蚕的急性毒性和生长发育毒性,为农桑混栽区害虫防治药剂选择提供参考。急性毒性试验结果表明:氰戊菊酯对2龄起蚕的96 h-LC50为0.251~0.570 mg·L^(-1),属于高毒和剧毒级别。生长发育毒性试验结果表明:亚致死剂量(0.062 8、0.020 9、0.006 98、0.002 33、0.000 775 mg·L^(-1))的氰戊菊酯处理对家蚕眠蚕体重和发育历期有一定的影响,但随着家蚕龄期的增长其影响逐渐减弱;0.002 33、0.000 775 mg·L^(-1)氰戊菊酯处理对家蚕化蛹率和死笼率有显著影响(P<0.05),对个体生长发育影响明显;0.062 8、0.020 9、0.006 98 mg·L^(-1)氰戊菊酯处理组家蚕茧层量显著低于对照组(P<0.05)。可见,氰戊菊酯对家蚕具有极高的急性毒性和慢性毒性效应。因此,在农桑混栽区使用氰戊菊酯时应注意,避免雾滴漂移或其他农事活动污染桑园引起家蚕中毒。

家蚕30K蛋白BmLP1的表达模式及其在胚胎中的作用

家蚕30K蛋白是家蚕血液和卵中的高丰度蛋白,参与营养、免疫、抑制细胞凋亡等功能.探究30K蛋白在家蚕体内的表达模式有助于更清楚地了解30K蛋白的功能.利用生物信息学方法发现4种30K蛋白基因Bmlp1,Bmlp2,Bmlp3和Bmlp7都含有信号肽.其中,Bmlp1与其他30K蛋白的序列相似性小于50%.半定量RT-PCR结果表明,Bmlp1从5龄第3 d到化蛹第1 d在脂肪体中表达量都比较高,之后表达量降低.Western blotting结果表明,BmLP1从5龄第5 d到化蛹第4 d在血淋巴中的含量都比较高,之后含量降低.与血淋巴中的变化趋势不同,卵巢中的BmLP1在上蔟第2 d被检测到,之后含量一直增加,化蛾时含量达到最高.这是由于上蔟第2 d卵巢管迅速长大,血液中的BmLP1等营养蛋白逐渐转运至卵巢管的未受精卵并开始积累.免疫组织化学定位结果表明,在胚胎发育前期,BmLP1分布于蚕卵的卵黄颗粒中,在孵化前期,BmLP1被吞入胚胎的肠道内.体外孵育结果表明,蚁蚕粗提物可以降解BmLP1,暗示蚁蚕肠道内可能存在某种蛋白酶可以将大部分BmLP1水解,最终为蚁蚕的孵化提供能量或者氨基酸.系统分析了BmLP1在不同发育时期脂肪体、血液、卵巢和胚胎中的表达特征,揭示了其在胚胎发育过程中的重要作用.

昆虫激素对家蚕不同组织β-N-乙酰葡萄糖苷酶活性的影响

【目的】研究蜕皮激素20E和保幼激素JH处理对家蚕5龄幼虫不同组织β-N-乙酰葡萄糖苷酶(β-N-acetylgucosaminidase,GlcNAcases)活性的影响,为深入解析家蚕GlcNAcases的生物学功能提供参考。【方法】利用微量注射器注射蜕皮激素20E和保幼激素JH,分别测定6、12、18、24和48 h家蚕幼虫血淋巴、脂肪体、中肠、表皮和丝腺中GlcNAcases的活性变化情况。【结果】在JH处理组,家蚕幼虫血淋巴GlcNAcases活性在12 h便开始显著增高,在18、24和48 h持续极显著高于对照组;在20E处理组,血淋巴GlcNAcases活性仅在24和48 h显著高于对照组。对于20E处理组和JH处理组,脂肪体组织GlcNAcases的活性变化情况相似,在6、12和18 h酶活性无显著变化,在24和48 h极显著高于对照组。经20E或JH处理后,中肠组织GlcNAcases活性在6和12 h均略高于对照组,但与对照组相比差异不显著;在18 h开始显著高于对照组,在24 h极显著高于对照组,随后在48 h酶活性降低至对照组水平。20E处理后,表皮GlcNAcases活性在12 h开始显著高于对照组,在18和24 h持续显著高于对照组,48 h酶活性降低至对照组水平。JH处理后,表皮组织GlcNAcases活性在12、18和24 h极显著低于对照组,在48 h恢复至对照组水平。丝腺组织中的GlcNAcases活性在20E处理12 h开始高于对照组,但差异不显著,随后酶活性持续增强,在18和24 h极显著高于对照组;在48 h有所降低,但仍显著高于对照组。JH处理12 h GlcNAcases活性开始降低,但与对照组相比差异不显著,18 h开始显著低于对照组,24和48 h持续极显著低于对照组。【结论】蜕皮激素20E和保幼激素JH对家蚕幼虫血淋巴、脂肪体和中肠中GlcNAcases活性具有一定的激活作用。在表皮和丝腺组织中,20E能促进并激活GlcNAcases的活性,而JH则抑制其的活性。这提示GlcNAcases在家蚕幼虫不同组织发挥的功能并不完全相同,并且不同激素对GlcNAcases活性的影响效果亦存在差异。

基于营卫理论探讨桂枝-赤芍配伍重塑肿瘤血管微环境的网络药理学机制

目的:采用网络药理学方法预测桂枝-赤芍配伍影响肿瘤血管生成的潜在靶点和通路,从分子网络药理学水平探索该配伍重塑肿瘤血管微环境的网络药理学机制。方法:采用中药系统药理学数据库与分析平台(TCMSP)检索桂枝、赤芍的化学成分和潜在靶点,选择口服生物利用度≥30%和类药性≥0.18作为化学成分筛选条件;在GeneCards数据库中检索血管生成的靶点;利用Cytoscape 3.6.0软件绘制桂枝-赤芍配伍-化合物-靶点-血管生成网络;使用STRING 11.0在线软件构建蛋白质-蛋白质相互作用(PPI)网络并挖掘核心靶点;采用David Bioinformatics Resources数据库对该复方活性成分潜在的靶点网络中的蛋白进行基因本体(GO)功能富集分析和京都基因与基因组百科全书(KEGG)通路富集分析。结果:桂枝-赤芍配伍的33种有效成分作用于血管生成过程的77个靶点,PPI网络的核心靶点包括蛋白激酶B(Akt)1、JUN、白细胞介素6、基质金属蛋白酶、血管内皮生长因子A、一氧化氮合酶2和缺氧诱导因子-1α等多个蛋白。GO功能富集分析提示,该配伍的关键蛋白主要参与了DNA结合转录激活剂活性、血红素结合、抗氧化活性、核受体活性和转录因子活性等生物过程。KEGG通路富集分析显示,该配伍参与了缺氧诱导因子-1(HIF-1)信号通路、肿瘤蛋白53信号通路、细胞凋亡信号通路、表皮生长因子受体酪氨酸激酶抑制剂耐药信号通路、血管内皮生长因子(VEGF)信号通路和磷脂酰肌醇3激酶-Akt信号通路等,提示桂枝-赤芍配伍与肿瘤血管生成的关系最为密切。结论:桂枝-赤芍配伍中的黄芩素、谷甾醇和鞣花酸等成分可能通过HIF-1信号通路、VEGF信号通路影响肿瘤血管生成,干预肿瘤的生物学行为。

新疆桑白皮提取物对主要致龋细菌生物膜作用的实验研究

目的探讨新疆桑白皮提取物对主要致龋细菌在生物膜状态下产酸、产糖等致龋毒力因子及生物膜活性的影响。方法制备变异链球菌、血链球菌和黏性放线菌3种单菌种菌悬液,分为阴性对照组[不添加新疆桑白皮提取物或氯己定(CHX)];阳性对照组(添加0.05%CHX);实验组(添加不同浓度新疆桑白皮提取物),测定新疆桑白皮提取物对3种致龋细菌生物膜状态下产酸能力的影响,通过测定24 h内不同时间节点pH值制作pH曲线。采用蒽酮硫酸法测定新疆桑白皮提取物对水溶性及水不溶性胞外多糖合成水平的影响。分别采用乳酸脱氢酶(Lactate dehydrogenase,LDH)活性试验和钙离子(Ca^(2+))泄漏实验,测定新疆桑白皮提取物对3种致龋菌生物膜上清液中LDH含量和Ca^(2+)浓度的影响;采用活死菌染色实验,测定新疆桑白皮提取物对3种致龋菌生物膜活性的影响。结果与阴性对照组比较,实验组(除1/4MBIC_(50)实验组)和CHX组生物膜ΔpH值均减小,3种致龋细菌单菌种生物膜产IEPS、SEPS能力降低,上清液中LDH含量和Ca^(2+)浓度升高,生物膜细菌总量下降,死细菌数量增大,活/死细菌比值百分比下降,差异有统计学意义(P<0.05)。与CHX组比较,实验组3种致龋细菌生物膜ΔpH值均增大,生物膜产IEPS、SEPS能力升高,上清液中LDH含量和Ca^(2+)浓度降低,差异有统计学意义(P<0.05)。结论新疆桑白皮对3种致龋细菌生物膜状态下产酸、产糖能力具有一定抑制作用,能够影响破坏3种致龋细菌生物膜的活性。

家蚕品种资源数量性状的因子分析和品种聚类

通过采用因子分析和品种聚类的方法,对家蚕品种资源进行综合评价,有助于提高品种资源鉴定的效率,并有利于合理有效地选择育种亲本,为育种工作提供重要参考。以60个家蚕品种资源为供试材料,对其主要数量性状进行因子分析,并根据其欧氏距离进行聚类分析。供试家蚕品种数量性状前5个因子累计贡献率达92.754 5%,其中茧丝产量构成因子为第1公因子,最大贡献率达45.954 8%;生命力构成因子为第2公因子,贡献率18.703 3%;第3公因子为解舒因子,贡献率12.561 2%;第4、5公因子为孵化率因子贡献率9.795 6%、茧丝纤度因子贡献率5.739 6%。在欧氏距离聚类图中,可把60个品种分成3大类,即28个品种组成的优质高产类群、19个品种组成的一般类群、13个品种组成的特殊性状遗传材料类群。第1、2公因子茧丝产量和生命力是家蚕育种中的两个主要指标,在各个世代选育过程中根据少数公因子和特殊因子进行选择与改良,提高育种效率。聚类分析能够揭示不同家蚕品种之间的相对遗传距离,能较好地为家蚕杂交育种和品种资源的利用及改良提供科学客观的依据。

家蚕蛹变态期的中肠发育变化观察及细胞凋亡与自噬相关基因的表达检测

为探究家蚕中肠在蛹变态过程中的形态发育变化,于家蚕5龄幼虫期、蛹期及蛾期以24h为间隔,对其中肠进行解剖观察,结果显示:家蚕5龄幼虫的中肠为长圆筒形,在食桑期呈绿色、膨大的管状,进入熟蚕期停止食桑后,中肠开始变黄、缩短;在熟蚕营茧化蛹的过程中,中肠持续缩短、变小,并随着发育时期的延长,最终呈椭圆形颗粒状,表面颜色由浅黄色变为棕黄色。进一步观察家蚕不同发育时期中肠组织的石蜡切片,发现幼虫中肠细胞在进入蛹变态期发生了多次凋亡与再生的过程,在上蔟3~4d、上蔟7~8d、上蔟12d~蛾期都形成了新的中肠上皮细胞,这些新的中肠上皮细胞可能是由再生细胞分化更新而来的。对家蚕中肠组织中细胞凋亡基因(Caspase-1、BmDredd)与自噬基因(Atg1、Atg13)表达模式的检测结果显示,Caspase-1、BmDredd在上蔟2d、7d、12d的表达量均降低,Atg1、Atg13在上蔟7d、9d、12d的表达量均降低,表明在家蚕的这些变态发育时期,其中肠细胞的凋亡受到了抑制,与切片观察新的中肠上皮细胞形成时期基本一致。研究结果呈现了家蚕中肠在蛹变态时期的发育变化过程,说明家蚕幼虫的中肠在蛹发育变态过程中并未彻底消亡,成虫的中肠是幼虫中肠在蛹变态时期经过多次消亡与再生过程发育而来的。

家蚕与桑树相互作用的研究现状及进展

栽桑养蚕是世界农耕文明的一大壮举。专食桑叶的家蚕由其祖先野桑蚕经人工驯化而来,是第一个完成全基因组测序的鳞翅目昆虫。本文综述家蚕与桑树协同进化方面的研究证据,包括家蚕蛋白酶与桑树蛋白酶抑制子的互作、家蚕对桑树次生代谢物质的适应以及桑树尿素酶对家蚕氮代谢的意义等,为今后深入解析家蚕与桑树的互作提供新见解,并丰富植食性昆虫与宿主植物互作的研究信息。

3种中药配方颗粒全生产链的污染微生物考察

目的:对郁金、桑叶、蝉蜕中药配方颗粒生产全过程污染微生物进行考察,建立数据库,探索中药配方颗粒生产过程微生物关键控制点及控制措施,为企业提供示范性研究,为制定标准、改进生产工艺提供依据,填补质量全过程控制的空白。方法:对3种中药配方颗粒的原材料、中间产品、成品按照《中国药典》2020年版进行分析检测,采用质谱技术对负载微生物进行鉴定,分析研究从药材原料到中药配方颗粒成品的外源性污染微生物的程度及容易污染微生物的种类。结果:3种中药配方颗粒的原材料(中药饮片)微生物污染较严重,原材料的耐热芽孢杆菌即使经过工艺处理后,仍能在中间产品、成品中检出,并造成部分批次需氧菌总数结果超出限度规定;中间产品、成品中还检出来源于人和动物肠道中的屎肠球菌。结论:①加强中药饮片的微生物污染控制,有利于降低终端产品的微生物负载;②3种中药配方颗粒的生产工艺存在芽孢类微生物污染的风险,需优化生产工艺参数来降低微生物负载;③药品生产企业需加强对产品全过程控制,降低微生物污染风险。

桑白皮提取物抑制高迁移率族蛋白/Toll样受体4通路对肺炎支原体肺炎大鼠的保护机制

目的:探究桑白皮提取物对肺炎支原体(MP)肺炎大鼠的药效,以及对高迁移率族蛋白(HMGB-1)/Toll样受体4(TLR4)信号通路的影响。方法:将Wistar雄性大鼠随机分为对照组、MP肺炎模型组、阿奇霉素(阳性对照)组及桑白皮提取物低、中、高剂量组[2、4、8 g/(kg·d)],每组各12只。除对照组外,其余大鼠构建MP肺炎大鼠模型,并给予相应剂量的药物处理。显微镜下计数肺泡灌洗液(BALF)中炎性细胞计数;采用酶联免疫吸附试验(ELISA)法检测血清中炎性细胞因子水平;苏木精-伊红(HE)染色观察肺组织病理变化;Western blotting法和免疫组化检测肺组织HMGB-1、TLR4、p-NF-κB p65蛋白表达水平。结果:对照组大鼠肺组织细胞排列正常,无病变;MP肺炎模型组大鼠肺组织异常,大量炎性细胞浸润;经桑白皮提取物给药后,大鼠肺组织损伤明显减轻,炎性细胞浸润明显减少。与对照组相比,MP肺炎模型组大鼠肺系数、BALF中炎性细胞计数、血清中白细胞介素(IL)-6、肿瘤坏死因子(TNF)-α水平及肺组织中HMGB-1、TLR4、p-NF-κB p65蛋白水平升高,IL-10水平降低(P<0.05)。与模型组相比,桑白皮提取物各剂量组和阿奇霉素组大鼠上述指标趋势相反(P<0.05)。结论:桑白皮提取物可能通过抑制HMGB-1/TLR4信号通路,减轻炎症反应,发挥对MP肺炎大鼠的保护作用。