酱香型白酒酿造酒醅中酵母菌多样性研究

为解析酱香型白酒酿造酒醅中酵母菌的菌群结构,获取酒醅中的主要酵母菌,采用高通量测序法分析酱香型白酒酒醅中酵母菌多样性及主要功能菌群,同时采用可培养分离方法获取酒醅中酵母菌活性菌株。从酱香型白酒下沙至五轮次酒醅中共检出59个属、129个种的酵母菌,分离得到酵母菌活性菌株41种,检测到的酵母菌种类与获得的酵母菌活菌在各香型白酒中最多。不同时期酒醅中的酵母菌种类和数量差异明显,其中下沙、造沙轮次以Pichia kudriavzevii为绝对优势酵母菌;一至五轮次随着轮次的递增,酒醅中优势酵母菌的种类增多,其中主要的优势酵母菌有Pichia kudriavzevii、Pichia manshurica、Zygosaccharomyces bailii、Saccharomyces cerevisiae、Candida apicola。酱香型白酒酒醅中蕴藏着极其丰富的酵母菌资源,对酵母菌菌群结构的解析有助于科学地认识酱香型白酒酿造过程中产酒与风味代谢机理,为发酵过程的调控提供一定依据。     

葡萄糖诱导绿色杜氏藻转录组及相关通路差异分析

绿色杜氏藻是研究耐盐机理的模式绿藻．葡萄糖不仅是营养物质,而且还是信号物质．目前,对绿色杜氏藻转录组、糖处理后差异表达基因和β-胡萝卜素生物合成途径关键基因表达还不清楚．本研究通过Illumina HiSeqTM 2000高通量测序,获得葡萄糖处理和未处理绿色杜氏藻转录组信息．利用P value值和差异倍数对样本进行差异表达分析,共111条转录本存在差异表达,3条为上调转录本,108条为下调转录本．利用RT-qPCR检验差异表达分析的准确性. 结果表明,转录本表达结果与转录组分析结果一致．GO功能富集结果表明,71条下调转录本与代谢相关,占所有下调转录本的65.74%．KEGG富集分析结果表明,21条KEGG通路含89条下调转录本,14条通路与代谢相关．代谢中通路最多的为能量代谢（6条）,含63条下调转录本．能量代谢中与光合作用相关的下调转录本最多,为29条．通过分析找到2条与β-胡萝卜素生物合成相关通路（MVA/MEP途径及β-胡萝卜素合成途径）,并发现通路的关键基因hmgs、dxs、dxr、psy、pds、chyb,对其进行差异表达分析,均不存在差异表达．研究表明,葡萄糖抑制了绿色杜氏藻光合作用,代谢受阻,但未影响β-胡萝卜素生物合成相关通路及关键基因．     

生物节律基因Timeless的生物学功能研究进展

Timeless基因广泛分布于生物体中,是主要的生物节律基因之一,它通过与节律基因Per和Cry家族成员的相互作用影响它们的表达水平。Timeless和Tipin能够稳定复制叉,促进姊妹染色单体凝聚,对DNA复制有促进作用;在细胞周期中激活S期检测点,参与ATR-Chk1和ATM-Chk2的DNA损伤修复通路,加强细胞周期的阻滞以修复DNA损伤。Timeless是生物节律和细胞周期的连接者,在多种癌组织(如肝癌、肺癌、乳腺癌、结直肠癌、肾癌和胰腺癌)中的表达水平与癌旁非癌组织相比有差异,提示Timeless表达异常可能与肿瘤的发生和发展相关。     

冷诱导RNA结合蛋白的生物学功能与信号通路

冷诱导RNA结合蛋白（ cold-inducible RNA-binding protein, CIRBP）是哺乳动物体内发现的第一个冷诱导蛋白。这种蛋白质在机体内各个组织与器官中均广泛表达,并在正常生理状态或应激条件下,广泛参与多个生物学过程,例如细胞增殖、发展、凋亡、分化和生物节律调节等多个方面。随着研究的深入,发现CIRBP具有一些新的功能,例如在一些炎症的发生和肿瘤的发生过程中,起到促进作用与作为新一代的原癌基因等。CIRBP发挥作用的信号通路,主要有胞外信号调节激酶/丝裂原活化蛋白激酶(extracellular signal-regulated kinases/mitogen-activated protein kinases, ERK/MAPK)、磷脂酰肌醇3激酶/蛋白激酶B(phosphatidylinositol 3-kinase/protein kinase B, PI3K/PKB)、无翅和整合基因(wingless and integration 1,Wnt)、核因子κB(nuclear factor κB, NF-κB)等。本文针对CIRBP的生物学功能和相关信号通路的最新研究进展加以综述,希望能为细胞生物学基础研究与利用该蛋白质进行临床有关疾病的诊治提供新的思路。     

Emodin suppresses oxaliplatin-induced neuropathic pain by inhibiting COX2/NF-κB mediated spinal inflammation

Oxaliplatin (OXA) is a common chemotherapy drug for colorectal, gastric, and pancreatic cancers. The anticancer effect of OXA is often accompanied by neurotoxicity and acute and chronic neuropathy. The symptoms present as paresthesia and pain which adversely affect patients' quality of life. Herein, five consecutive intraperitoneal injections of OXA at a dose of 4 mg/kg were used to mimic chemotherapy. OXA administration induced mechanical allodynia, activated spinal astrocytes, and increased inflammatory response. To develop an effective therapeutic measure for OXA-induced neuropathic pain, emodin was intrathecally injected into OXA rats. Emodin developed an analgesic effect, as demonstrated by a significant increase in the paw withdrawal threshold of OXA rats. Moreover, emodin treatment reduced the pro-inflammatory cytokines (tumor necrosis factor-α and interleukin-1β) which upregulated in OXA rats. Furthermore, autodock data showed four hydrogen bonds were formed between emodin and cyclooxygenase-2 (COX2), and emodin treatment decreased COX2 expression in OXA rats. Cell research further proved that emodin suppressed nuclear factor κB (NF-κB)-mediated inflammatory signal and reactive oxygen species level. Taken together, emodin reduced spinal COX2/NF-κB mediated inflammatory signal and oxidative stress in the spinal cord of OXA rats which consequently relieved OXA-induced neuropathic pain.     

Ancestral niche separation and evolutionary rate differentiation between sister marine flavobacteria lineages

Marine flavobacteria are specialists for polysaccharide degradation. They dominate in habitats enriched with polysaccharides, but are also prevalent in pelagic environments where polysaccharides are less available. These niches are likely occupied by distinct lineages, but evolutionary processes underlying their niche differentiation remain elusive. Here, genomic analyses and physiological assays indicate that the sister flavobacteria lineages Leeuwenhoekiella and Nonlabens likely explore polysaccharide-rich macroalgae and polysaccharide-poor pelagic niches respectively. Phylogenomic analyses inferred that the niche separation likely occurred anciently and coincided with increased sequence evolutionary rate in Nonlabens compared with Leeuwenhoekiella. Further analyses ruled out the known mechanisms likely driving evolutionary rate acceleration, including reduced selection efficiency, decreased generation time and increased mutation rate. In particular, the mutation rates were determined using an unbiased experimental method, which measures the present-day populations and may not reflect ancestral populations. These data collectively lead to a new hypothesis that an ancestral and transient mutation rate increase resulted in evolutionary rate increase in Nonlabens. This hypothesis was supported by inferring that gains and losses of genes involved in SOS response, a mechanism known to drive transiently increased mutation rate, coincided with evolutionary rate acceleration. Our analyses highlight the evolutionary mechanisms underlying niche differentiation of flavobacteria lineages.     

Effects of Mn2+ on neutral lipid content,C4 pathway,and related gene expression in Phaeodactylum tricornutum

Journal of Applied Phycology - The neutral lipids from the diatom Phaeodactylum tricornutum are a valuable substance with a vital role in biofuel. Increasing the neutral lipid content of P....