Clinal variation for only some phenological traits across a species range

Phenology is the timing of life cycle events of an organism. Alterations in phenology can have profound effects on individual fitness, population growth, and community dynamics. Recent changes in climate have altered the phenology of many organisms, which may result in selection to shift phenological traits. Understanding the relationship between local climates and population differentiation in phenology will allow us to anticipate responses to novel selective environments caused by global climate change. We evaluated population differentiation in the number of days to germination, first flower, and fruit maturation for 33 populations throughout the range of Campanulastrum americanum (American Bellflower). Germination and fruit maturation had geographical clines with earlier timing in populations from northern latitudes. Northern sites were cooler and drier, suggesting potential adaptive differentiation of the shorter life cycle associated with earlier phenology. Similarly, higher elevations were cooler and had earlier fruit maturation. However, seed germination was later in higher elevation populations. Although there was substantial variation in the day to first flower, ranging 40 days between population means, it was idiosyncratic and not related to latitude, suggesting differentiation in response to selective factors distinct from those on germination and fruit maturation. Thus, germination and fruit maturation in C. americanum may shift in response to selection by rising temperatures. However, such changes are not expected for flowering time, a typical indicator of climate change.     

Functional dissection and modulation of the BirA protein for improved autotrophic growth of gas-fermenting Clostridium ljungdahlii

Gas-fermenting Clostridium species can convert one-carbon gases (CO₂/CO) into a variety of chemicals and fuels, showing excellent application prospects in green biological manufacturing. The discovery of crucial genes and proteins with novel functions is important for understanding and further optimization of these autotrophic bacteria. Here, we report that the Clostridium ljungdahlii BirA protein (ClBirA) plays a pleiotropic regulator role, which, together with its biotin protein ligase (BPL) activity, enables an effective control of autotrophic growth of C. ljungdahlii. The structural modulation of ClBirA, combined with the in vivo and in vitro analyses, further reveals the action mechanism of ClBirA’s dual roles as well as their interaction in C. ljungdahlii. Importantly, an atypical, flexible architecture of the binding site was found to be employed by ClBirA in the regulation of a lot of essential pathway genes, thereby expanding BirA’s target genes to a broader range in clostridia. Based on these findings, molecular modification of ClBirA was performed, and an improved cellular performance of C. ljungdahlii was achieved in gas fermentation. This work reveals a previously unknown potent role of BirA in gas-fermenting clostridia, providing new perspective for understanding and engineering these autotrophic bacteria.     

KL2型鲍曼不动杆菌噬菌体解聚酶克隆及抗菌活性分析

【背景】噬菌体解聚酶是噬菌体在裂解细菌过程中产生的一种抗菌蛋白,关于鲍曼不动杆菌荚膜分型及常见型别噬菌体解聚酶的研究报道较少。【目的】以KL2型鲍曼不动杆菌为研究对象,从噬菌体IME-AB2中克隆解聚酶,在大肠杆菌中进行可溶性表达并研究其体外抗菌活性。【方法】应用二代测序及生物信息学方法鉴定鲍曼不动杆菌荚膜型,分析IME-AB2全基因组。应用分子克隆技术克隆ORF76假定的尾丝蛋白(Putative Tail Fiber)基因,构建重组表达载体pEASY-Blunt-E1-gp76,在大肠杆菌BL21(DE3)中诱导表达,通过Ni-NTA亲和层析纯化解聚酶,研究解聚酶体外抗菌活性。【结果】构建了pEASY-Blunt-E1-gp76解聚酶重组表达质粒,该重组质粒在大肠杆菌中得到可溶性表达;体外活性分析显示,该重组蛋白在体外能够对所有的KL2型鲍曼不动杆菌具有较好的抗菌活性,解聚酶联合人和狗的血清具有很好的杀菌活性。【结论】鉴定解聚酶并提高其抗菌谱具有重要意义,也是噬菌体及解聚酶用于治疗耐药菌研究领域急需解决的重要问题之一。     

Species Diversity of Arbuscular Mycorrhizal Fungi in the Rhizosphere of <i>Hevea brasiliensis</i> in Hainan Island,China

Hevea brasiliensis is one of the important economic trees with a great economic value for natural rubber production. Symbiosis between roots of H. brasiliensis and arbuscular mycorrhizal fungi (AMF) is widely recognized, and can provide a range of benefits for both of them. Hainan Island harbors is one of the largest plantations of H. brasiliensis in China, whereas the information regarding the diversity of AMF in the rhizosphere of H. brasiliensis on this island is scarce. The diversity of AMF species in the rhizosphere of rubber tree plantations in Hainan was investigated in this study. A total of 72 soil samples from the rhizosphere of H. brasiliensis RY7-33-97 were collected. These included 48 samples from plantations in 11 cities or counties that had been planted for 15–25 years, and 24 samples from a demonstrating plantation site of the China National Rubber Tree Germplasm Repository representing plantations with tree plantation ages from one to 40 year-old. Collectively, a total of 68 morphotypes of AMF, belonging to the genera of Archaeospora (1), Glomus (43), Acaulospora (18), Entrophospora (3), Scutellospora (2), and Gigaspora (1) were isolated and identified, as per morphological characteristics of spores presented in the collected soil samples. Glomus (Frequency, F = 100%) and Acaulospora (F = 100%) were the predominant genera, and A. mellea (F = 63.9%) and A. scrobiculata (F = 63.9%) were the predominant species. AMF species differed significantly among collected sites in spore density (SD, 290.7–2,186.7 spores per 100 g dry soil), species richness (SR, 4.3–12.3), and Shannon-Weiner index of diversity (H, 1.24–2.24). SD was negatively correlated with available phosphorus level in the soil; SR was positively correlated with soil total phosphorus content; and H was positively correlated with levels of soil organic matter and total phosphorus. Similarly, SD, SR, and H were also correlated with H. brasiliensis plantation age, and an increasing trend was observed up to 40 years. These results suggest that the AMF community was complex and ubiquitous in the island plantation ecosystems of H. brasiliensis, with high species abundance and diversity. Soil factors and plantation age dramatically affected AMF diversity at species level.     

Atiprimod triggered apoptotic cell death via acting on PERK/eIF2α/ATF4/CHOP and STAT3/NF-ΚB axis in MDA-MB-231 and MDA-MB-468 breast cancer cells

Molecular Biology Reports - The constitutive activation of STAT3 through receptor tyrosine kinases triggered breast cancer cell growth and invasion-metastasis. Atiprimod impacts anti-proliferative,...     

保守性和根治性手术治疗对卵巢良性肿瘤蒂扭转的疗效和术后激素水平比较

目的:观察保守性和根治性手术治疗卵巢良性肿瘤蒂扭转的有效性和安全性。方法:选取2017年2月~2020年5月间入院治疗的60例确诊为卵巢良性肿瘤蒂扭转的患者,根据患者意愿及病情发展情况分为两组,保守治疗组26例,切除治疗组34例。保守性手术组(The conservative operation group,COG)术前应根据患者的疼痛性质判断扭转组织的基本情况制定多套方案,术中先以钳夹等方式结扎卵巢动静脉以免形成栓塞,然后进行扭转复位并观察血流恢复情况,待恢复接近正常时可剥离囊肿。切除治疗组(The radical operation group,ROG)结扎卵巢动静脉,将扭转蒂复位观察卵巢颜色、质地等,若出现破裂、坏死、无法恢复等情况时给予切除。比较两种治疗方法前后患者血清黄体生成素(luteinizing hormone,LH)、卵泡刺激素(follicle-stimulating hormone,FSH)、雌二醇(Estradiol,E2)等变化,评估卵巢的激素分泌情况,并记录其他并发症的发生率。结果:(1)保守性治疗组卵巢均成功保留,两组患者均恢复良好,比较两组患者的平均手术时间、术中出血量及住院时间,结果显示无统计学差异(P>0.05);(2)随访半年,比较术前,术后3个月、6个月两组患者LH、FSH、E2的变化情况,术前各指标无显著差异(P>0.05);(3)比较两组患者术中并发症发生率,无显著差异(P>0.05)。结论:本研究比较了保守性手术和切除手术治疗卵巢肿瘤蒂扭转的有效性与安全性,26例保守性治疗患者手术卵巢均保留成功,预后卵巢功能、并发症的发生率与切除治疗组无显著差异,可进行临床推广。     

不同液体复苏在腹部多发伤导致失血性休克救治中的效果对比研究

目的:比较不同液体复苏在腹部多发伤导致的失血性休克救治中的临床效果及安全性。方法:选取2017年7月至2019年12月我院救治的因高处坠落、交通事故等意外事件导致腹部多发伤且失血性休克的患者83例,根据入院时间分为2组,对照组(于2017年7月至2018年7月入院治疗)和研究组(于2018年8月至2019年12月入院治疗)。在治疗过程中,对照组采用常规充分液体复苏;研究组采用限制性液体复苏。观察和比较两组患者临床治疗效果、血液酸度及其他相关指标。结果:复苏后,两组动脉血氧分压(Partial arterial oxygen pressure, PaO₂)均较复苏前显著下降(P<0.05),对照组PaO₂较研究组更明显,在复苏后90 min、120 min,对照组PaO₂明显低于研究组(P<0.05)。两组复苏后动脉血二氧化碳分压(Partial pressure of blood carbon dioxide, Pa CO2)均呈现先下降后上升的变化趋势,对照组Pa CO2均显著高于研究组(P<0.05)。从复苏前到复苏后,两组p H值均呈现先降后升的变化趋势,同时在复苏后90 min、120 min研究组p H值均显著高于对照组(P<0.05)。与复苏前相比,两组复苏后PT值均显著上升(P<0.05),研究组复苏后90 min、120 min PT值明显低于对照组(P<0.05),复苏后谷丙转氨酶(Alanine aminotransferase, ALT)、谷草转氨酶(Aspartate aminotransferase, AST)及肌酐水平均明显低于对照组(P<0.05)。对照组共有9例(22.50%)患者出现并发症或死亡,研究组共有5例(11.62%)患者出现并发症,无死亡;不良预后发生率明显低于对照组(P<0.05)。结论:对腹部多发伤失血性休克患者而言,采用早期限制性液体复苏可有效恢复患者血容量,对血液携氧能力、肝肾功能影响较小,安全性高,有利于患者预后恢复。     

新疆和田、哈密和阿勒泰市居民指甲中氢、氧稳定同位素的比较

在法庭科学研究领域,指甲作为一种新型生物信息载体,在物证信息挖掘方面具有重要的价值。人生命活动中摄入的氢、氧主要来源于饮用水、摄入的食物和空气等,其中的氢、氧稳定同位素比值信息会被指甲角蛋白记录并保存下来,这些信息可以用于推断人的生活地域变化情况,在个体身份的排查工作中具有重要的作用。本文借助元素分析-稳定同位素比质谱技术（EA-IRMS）对新疆和田、哈密和阿勒泰3个城市常住居民指甲中氢、氧稳定同位素比值进行了分析,并借助判别分析模型对指甲样本的氢、氧稳定同位素比值进行了模式识别。结果表明,3个不同城市常住居民指甲氢、氧稳定同位素比值存在一定的差异;和田指甲样本δ²H值与哈密、阿勒泰有明显差异;哈密指甲样本δ²H值与阿勒泰重叠范围宽,差异较小;3个城市δ¹⁸O值分布均有重叠,无明显的差异。在判别模型中,通过判别函数f(x,y)=0.992x+0.046y和判别函数f(x,y)=-0.198x+1.009y对3个市共计85份样本进行判别分析,总体分类准确率为95.29 %,9个验证样本均实现了准确的归类和判定。本文研究表明,不同城市居民指甲中的氢、氧稳定同位素比值是存在一定差异的,采用EA-IRMS结合判别分析能初步实现不同城市居民的区分。     

辣木叶对糖尿病大鼠认知功能及海马神经细胞凋亡的影响*

目的:探讨辣木叶对链脲佐菌素(STZ)诱导的糖尿病模型大鼠认知功能障碍及海马神经细胞凋亡的影响。方法:选取健康SD雄性大鼠50只,随机选取10只作为对照组,40只大鼠给予腹腔注射25 mg/kg STZ构建糖尿病大鼠模型。40只大鼠随机分为模型组、辣木高、中、低剂量组,分别每日灌胃给药2.0 g/kg、4.0 g/kg、8.0 g/kg辣木叶,对照组和模型组每日灌胃给药等量生理盐水,1次/日,持续给药8周。Morris水迷宫实验评价大鼠学习记忆能力;HE染色及免疫组化染色对大鼠海马神经元切片进行染色,观察各组大鼠海马神经元病理改变的情况及Bax、caspase-3及Bcl-2蛋白表达情况;酶联免疫法(ELISA)检测大鼠海马组织中肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)。结果:与对照组相比,模型组大鼠血糖值明显提高(P＜0.01),血胰岛素水平明显降低(P＜0.05);与模型组相比,辣木组血糖值显著降低(P＜0.05,P＜0.01),辣木中、高剂量组血胰岛素水平显著升高(P＜0.05,P＜0.01)。不同剂量组辣木组间比较,给药后3组大鼠FBG及INS无统计学差异(P＞0.05);Morris水迷宫实验的第4-5日,与模型组相比较,辣木各剂量组潜伏期均明显缩短(P＜0.05);辣木不同剂量组目标象限停留时间明显延长(P＜0.05)。炎症因子变化结果,与模型组相比较,辣木低、中、高剂量组TNF-α、IL-6含量及蛋白表达水平显著降低(P＜0.05)。HE染色及免疫组化染色结果显示,与模型组相比较,辣木中剂量组中阳性表达,呈棕黄色,细颗粒状。辣木叶中剂量组(53.21±7.19)能显著减少神经元细胞凋亡的数目(P＜0.01);辣木组中剂量组大鼠海马组织中Bax、caspase-3的蛋白表达及Bax/Bcl-2比例显著降低(P＜0.05)。结论:辣木叶能改善糖尿病大鼠认知功能障碍其作用机制可能与调节Bax、Bcl-2、caspase-3的蛋白表达,降低炎症因子TNF-α及IL-6含量相关。