香菇数量性状的相关性分析和主成分分析

对110个香菇杂交菌株16个数量性状进行表型、遗传和环境相关性分析及主成分分析。由分析结果可知,单菇鲜重与有关单菇的其他5个性状在表型、遗传和环境等3个方面都存在极显著的正相关,与菇数存在3种极显著的负相关,与CMC酶活性、木聚糖酶活性分别呈显著和极显著遗传负相关。鲜菇总重与出菇期和原基期呈极显著的表型和遗传负相关,与菇数、两种菌丝生长速度及菌盖厚度呈极显著的遗传正相关。结果表明,在香菇育种工作中,菌丝生长速度和酶活性,可以作为对单菇性状和鲜菇总重进行选择的间接指标之一。主成分分析结果表明,16个性状可以缩减为6个主成分,按方差贡献率大小分别命名为单菇、发育、产量、酶活、原基和转色因子,6个主成分的方差累积贡献率为80.75%。在香菇育种中,可以按照育种目标对上述主成分因子或其分量进行单独选择。     

不同浓度的添加剂 N2和 B27对神经干细胞增殖的影响

目的：通过比较添加不同浓度的无血清培养添加剂N2、B27对神经干细胞增殖的影响,探讨一种最优的体外培养大鼠胚胎神经干细胞的方法。方法：分离培养胚胎13．5dSD大鼠的神经干细胞,采用CCK-8细胞计数、BrdU掺入、测量神经球直径的方法,比较不同浓度N2、B27对神经干细胞增殖的影响。结果：N2与B27合用对神经干细胞增殖和成球的作用最为明显,单独添加2％B27的作用优于1％B27和N2组。结论：1％N2和1％B27同时添加更有利于神经干细胞的增殖和自我更新,此方法为神经干细胞的应用提供了实验依据。     

中国香菇自然种质的rDNA遗传多样性分析

测定了全国范围内的59个野生香菇菌株rDNA的ITS区域的序列。所得序列的总长度在723-727个碱基之间,G+C含量也基本稳定在57.5%左右。用Phylip3.6软件包对59个ITS序列进行DNA数据分析。结果表明59个菌株被划分到3个不同的谱系中,其中谱系Ⅰ包括11个菌株,分布较为均衡,涉及东北、西北、西南和东部沿海等地区的8个省份;谱系Ⅱ包括14菌株,以西北、西南的4个省份为主;谱系Ⅲ包括34个菌株,覆盖范围最广,除东北和西北高原地区外,其它均有涉及。地缘关系分析表明以陕、甘为主的西北高原地区的菌株涉及Ⅰ、Ⅱ两个谱系;以闽、浙、赣和台湾为主的东部沿海地区的菌株涉及Ⅰ、Ⅲ两个谱系;而以云、贵、川为主的西南地区的菌株则覆盖到了所有的3个谱系。这三个地区的香菇遗传多样性最丰富,西南地区尤为突出,是香菇种质资源保护与利用的重点区域。     

Amelioration of sepsis by inhibiting sialidase-mediated disruption of the CD24-SiglecG interaction

Suppression of inflammation is critical for effective therapy of many infectious diseases. However, the high rates of mortality caused by sepsis attest to the need to better understand the basis of the inflammatory sequelae of sepsis and to develop new options for its treatment. In mice, inflammatory responses to host danger-associated molecular patterns (DAMPs), but not to microbial pathogen-associated molecular patterns (PAMPs), are repressed by the interaction [corrected] of CD24 and SiglecG (SIGLEC10 in human). Here we use an intestinal perforation model of sepsis to show that microbial sialidases target the sialic acid-based recognition of CD24 by SiglecG/10 to exacerbate inflammation. Sialidase inhibitors protect mice against sepsis by a mechanism involving both CD24 and Siglecg, whereas mutation of either gene exacerbates sepsis. Analysis of sialidase-deficient bacterial mutants confirms the key contribution of disrupting sialic acid-based pattern recognition to microbial virulence and supports the clinical potential of sialidase inhibition for dampening inflammation caused by infection.     

Peritumoral monocytes induce cancer cell autophagy to facilitate the progression of human hepatocellular carcinoma

Macroautophagy/autophagy is an important catabolic process mediating cellular homeostasis and plays critical roles in cancer development. Whereas autophagy has been widely studied in various pathological models, little is known about the distribution, clinical significance and regulatory mechanism of this process in human hepatocellular carcinoma (HCC). In the present study, we found that tumor tissues exhibited significantly increased levels of autophagy compared with non-tumor tissues, and cancer cells with higher levels of autophagy were predominantly enriched in the invading edge regions of human HCC. Increased MAP1LC3B/LC3B expression in the invading edge regions was significantly correlated with a higher density of closely located monocytes, and TNF and IL1B derived from tumor-activated monocytes synergistically induced cancer cell autophagy in the invading edge regions of HCC. Monocyte-elicited autophagy induced the epithelial-mesenchymal transition (EMT) of cancer cells and promoted tumor metastasis by activating the NFKB-SNAI1 signaling pathway. Moreover, the increase of LC3B⁺ cancer cells in the invading edge areas was associated with high mortality and reduced survival of patients with HCC. These findings indicated that cancer cell autophagy is regulated by a collaborative interaction between tumor and immune cell components in distinct HCC microenvironments, thus allowing the inflammatory monocytes to be rerouted in a tumor-promoting direction.     

氰戊菊酯和苯巴比妥钠对敏感和抗性棉铃虫中肠多功能氧化酶系的诱导作用

用苯巴比妥钠（2mg/g）和氰戊菊酯（0.2mg/g）拌饲料处理,对敏感品系棉铃虫Helicoverpa armigera中肠的细胞色素P450和细胞色素c还原酶含量均具有明显的诱导作用（两者都使细胞色素P450含量提高了2.24倍,使细胞色素c还原酶的含量分别提高1.33和1.40倍）,但对细胞色素b5诱导作用不显著（仅为对照的1.23和1.15倍）;此外,苯巴比妥钠对敏感棉铃虫中肠的艾氏剂环氧化酶活性和甲氧试卤灵-O-脱甲基酶活性也有显著的诱导作用（分别提高了2.75和2.66倍）,但对7-乙氧香豆素-O-脱乙基酶活性没有诱导作用,而氰戊菊酯对敏感棉铃虫中肠的艾氏剂环氧化酶活性则有2.02倍的诱导作用。同一浓度的苯巴比妥钠和氰戊菊酯使抗性品系棉铃虫中肠的细胞色素P450含量分别提高1.21和1.15倍,使细胞色素c还原酶含量分别提高1.48和1.86倍（差异显著）,但是细胞色素b₅含量没有明显变化（分别为对照的1.15和0.98倍）;此外,氰戊菊酯能使抗性棉铃虫中肠的艾氏剂环氧化酶活性提高1.53倍,但苯巴比妥钠对该酶活性则有明显抑制作用。     

响应面法优化黑土豆色素提取工艺研究

以黑土豆为原料提取色素,在乙醇浓度、回流温度、回流时间和料液比四个单因素实验基础上,通过响应面法优化提取条件,利用 Box-Benhnken 设计模型,研究四个自变量之间的影响.结果表明,得到最佳提取工艺为回流温度47℃,回流时间47．5 min,料液比1∶90,乙醇浓度42．5％.在此条件下,理论上测得黑土豆中色素的吸光度值为0．413,实验测得黑土豆中色素的吸光度值为0．416,理论值与实验值的相对误差为0．726％.该提取工艺简便、具有较高的重现性和可行性.     

Characteristics of soil nematode community along an age sequence of sandy desert soil cultivation in a marginal oasis of middle reaches of Heihe River

This paper studied the characteristics of soil nematode community following the conversion of native sandy desert soil to irrigated farmland in a marginal oasis of the middle reaches of Heihe River basin, aimed to approach the bioindicating function of soil nematodes in soil evolution process. A total of 27921 soil nematode individuals were captured, belonging to 25 families and 34 genera. The total number of nematodes increased gradually with increasing age of cultivation. At all sampling sites, bacterivores and plant parasites were the dominant trophic groups, and made up the main parts of nematode community in oasis farmland. Through the analysis of the evenness index (J) and dominance index (lambda) of nematode community, the ecosystems were found to be fragile for the farmlands having cultivated for 0, 10, and > 50 years. The maturity index MI2-5 and MMI decreased with increasing cultivation age, suggesting that the practice of agricultural use enhanced the disturbance on farmland. The soil properties changed significantly after 10 years of cultivation, which was at a significant change stage for the structure stability of soil ecosystems. The characteristics of soil nematode community could be used as the bioindicator of soil evolution following the conversion of native desert soil to irrigated farmland.