纤维素酶与木质纤维素生物降解转化的研究进展

利用纤维素酶将预处理后的秸秆降解成可发酵性单糖,然后发酵生产所需的液体燃料及化工产品的技术,对于我国解决能源、环境、人口就业等难题有着巨大的积极影响。在木质纤维素生物降解转化工艺中,减少纤维素酶用量及提高酶解效率是降低木质纤维素降解成本的关键。纤维素酶系和木质纤维素酶水解技术的改进需要深入了解纤维素酶系统的组成及其协同作用、纤维素酶的结构与功能以及纤维素酶的生产技术。将就以上几个方面的研究进展进行讨论,并深入探讨了纤维素酶糖化能力的评价方法。     

Molecular dynamics simulations and statistical coupling analysis reveal functional coevolution network of oncogenic mutations in the CDKN2A–CDK6 complex

Coevolution between proteins is crucial for understanding protein–protein interaction. Simultaneous changes allow a protein complex to maintain its overall structural–functional integrity. In this study, we combined statistical coupling analysis (SCA) and molecular dynamics simulations on the CDK6–CDKN2A protein complex to evaluate coevolution between proteins. We reconstructed an inter-protein residue coevolution network, consisting of 37 residues and 37 interactions. It shows that most of the coevolved residue pairs are spatially proximal. When the mutations happened, the stable local structures were broken up and thus the protein interaction was decreased or inhibited, with a following increased risk of melanoma. The identification of inter-protein coevolved residues in the CDK6–CDKN2A complex can be helpful for designing protein engineering experiments.     

Identification of potential key genes in anaplastic thyroid cancer using bioinformatics analysis

Anaplastic thyroid cancer (ATC) has a high degree of malignancy and poor prognosis. The purpose of this study was to determine differentially expressed genes (DEGs) in ATC through biometric analysis technology, clarify potential interactions between them, and screen genes related to the prognosis of ATC. Using obtained DEGs, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Protein-protein interaction (PPI), and survival analysis were performed. After R integration analysis of the four datasets, 764 DEGs were obtained, i.e., 314 upregulated genes and 450 downregulated genes. Among the hub DEGs obtained from the PPI network, the expression levels of TYMS, FN1, CHRDL1, SDC2, ITGA2, COL1A1, COL9A3, and COL23A1 were associated with ATC prognosis. These results showed that the recurrence-free survival (RFS) of ATC was associated with TYMS, FN1, ITGA2, COL23A1, SDC2, and CHRDL1 statistically significantly in the KM plotter (P<0.05). Thus, the study suggests that TYMS, FN1, ITGA2, COL23A1, SDC2, and CHRDL1 may be used as potential biomarkers of ATC. These findings provide new insights for the detection of novel diagnostic and therapeutic biomarkers for ATC.     

社区对普氏原羚的保护态度和意愿及其影响因素

普氏原羚(Procapra przewalskii)是我国的特有种,青海湖地区是其唯一的分布区,青海湖国家级自然保护区对普氏原羚的有效保护、社区发展与保护之间矛盾的协调,对于生物多样性保护具有重要意义。了解青海湖国家级自然保护区周边社区对普氏原羚的保护态度、意愿及其影响因素,可以为自然保护区开展生物多样性保护工作,维持当地生态和平发展提供保障。基于问卷调查法对自然保护区周边社区的牧民和居民进行了调查,研究表明:(1)受访者认为草场质量退化(n=92,65.25%)和草场围栏设置(n=80,56.74%)是威胁普氏原羚的主要因素;在以保护普氏原羚和给予生态补偿为前提下,牧民拆除围栏的意愿有所提高(由20.78%分别提高至34.21%和40.79%);(2)管理部门的宣教活动(79.43%)、手机(31.91%)和电视(28.37%)等媒体报道是受访者了解野生动物保护相关政策法规的主要渠道,可以增进受访者对政策法规的了解,积极影响受访者对普氏原羚的认知(P < 0.01)、保护态度(P < 0.01)和保护意愿(P < 0.01);(3)受访者一致认为自然保护区的严格管理与保护(牧民94.81%,居民96.87%)、当地牧民对普氏原羚的包容与保护(牧民97.40%,居民87.50%)是普氏原羚能够在自然保护区周边生存的主要原因;(4)受访者对普氏原羚的保护态度和意愿均较高,且愿意参与宣传教育(92.91%)和社区共管(87.94%)工作;(5)除了受访者的文化程度、年龄、宗教信仰和家庭年收入的影响,对政策法规的了解及拆除围栏认同度是影响受访者对普氏原羚保护态度和意愿的关键因素(P < 0.01)。因此,建议自然保护区以国家公园建设为契机,加强协调保护与发展的科学研究,深入开展宣传教育,增进社区对自然保护区生物多样性的认识,提升社区共管参与度。     

不同温度处理对珠芽魔芋球茎休眠调控的影响

为探究不同温度处理对珠芽魔芋球茎休眠调控的影响,以珠芽魔芋叶面球茎为材料,在球茎休眠期设置昼/夜变温（24℃/9℃、24℃/13℃、24℃/17℃）、恒温（9℃、13℃、17℃、21℃）及室温处理,萌发期设置26℃、33℃催芽处理,分析不同温度处理后珠芽魔芋球茎在休眠 Ⅰ 期、休眠 Ⅱ 期以及萌发前期、中期、后期、末期的生物表型变化、内源生理变化规律及其休眠调控相关基因的变化情况。结果表明：（1）休眠期恒温处理有利于提高珠芽魔芋球茎的出芽比,其中13℃恒温打破休眠和萌发期33℃催芽处理球茎的发芽率最先达到峰值,且其出芽比最高。（2）休眠Ⅱ期的球茎淀粉含量低于休眠Ⅰ期,而其可溶性糖含量高于休眠Ⅰ期,13℃恒温处理球茎淀粉含量下降最快,其可溶性糖含量最高;前期恒温处理球茎淀粉、可溶性糖含量在萌发前期和萌发后期之间均存在显著性差异（P＜0.05）,而前期昼夜变温处理球茎仅可溶性糖含量在萌发前期和萌发后期之间存在显著性差异（P＜0.05）。（3）珠芽魔芋球茎ABA含量在休眠 Ⅰ 期和休眠 Ⅱ 期逐渐增多,而其GA3含量逐渐减少,萌发期珠芽魔芋球茎ABA含量呈现“先升后降”的规律,26℃催芽处理的珠芽魔芋球茎GA3含量呈现“先升后降”的规律,33℃催芽处理的珠芽魔芋球茎GA3含量整体呈上升的趋势。（4）珠芽魔芋NCED基因表达量随着休眠程度的加深逐渐增加,而在萌发期逐渐减少,CYP707A基因表达量随着休眠的加深逐渐减少,而在萌发期表达量增加。研究发现,珠芽魔芋打破休眠的最佳温度为恒温13℃,促进萌发的最佳温度为33℃;随着珠芽魔芋打破休眠,球茎中的淀粉含量降低,可溶性糖含量升高;ABA含量“先升后降”,GA3含量“先降后升”;NCED和CYP707A基因可能是珠芽魔芋休眠调控中的关键基因。     

Expression of Matrix Metalloproteinase-9, Type IV Collagen and Vascular Endothelial Growth Factor in Adamantinous Craniopharyngioma

To explore the expression of matrix metalloproteinase 9 (MMP-9), type IV collagen (Col IV) and vascular endothelial growth factor (VEGF) in adamantinomatous craniopharyngioma (ACP) and analyze the correlation between the level of these markers and adamantimous craniopharyngiomas recurrence. Expressions of MMP-9, Col IV and VEGF were tested by immunohistochemistry (IHC) in 40 cases of ACP, including 24 cases of primary group and 16 cases of recurred group. The expression level of MMP-9 and VEGF in recurred group were significantly higher than primary group (93.7% vs. 41.7%, P < 0.05, 87.5% vs. 45.8%, P < 0.05, respectively). The expression of Col IV in the recurred group was significant different from the primary group (Z = −2.619, P < 0.05). MMP-9, Col IV and VEGF may be the potential specific bio-marker related to the recurrence of ACP.