河北地区沿海盐场卤虫品系的组成

对河北地区海丰盐场和王凤玉盐场的卤虫品系组成情况进行了分析,结果显示,由于人为引种及在虾蟹育苗中不同品系卤虫卵的不当使用,使得该地区卤虫由原来单一的孤雌生殖品系组成变为目前的本地孤雌生殖卤虫、两性生殖的旧金山卤虫(Artemia franciscana)以及中华卤虫(A.sinica)混杂组成,其中外来种旧金山卤虫为优势种群,中华卤虫只是偶尔见到。由于竞争排斥效应,孤雌生殖和两性生殖卤虫产生了生态位的分化,孤雌生殖卤虫主要分布在低盐度的盐池,两性生殖卤虫主要分布在高盐度的盐池。     

用微型动物预测保定鲁岗污水处理厂活性污泥系统理化参数

用微型动物预测了保定鲁岗污水处理厂活性污泥系统的理化参数。建立的4个多元线性回归方程对出水BOD5、出水TN、SVI和出水SS做预测,分别需5、5、8和5种微型动物,预测成功率分别为78·7%、79·3%、89·5%和62·3%。     

铜锈环棱螺对藻华水体理化指标的影响

采用池塘围隔对比试验的方法,研究了不同密度(392 ind·m^-2、196 ind·m^-2、98 ind·m^-2、0 ind·m^-2)铜锈环棱螺(Bellamyaaeruginosa)对藻华水体主要理化因子的影响.实验从2009年9月14日开始,持续60d.结果显示:环棱螺可以明显提高藻华水体的透明度(SD),实验中、后期,三个处理组围隔水体的SD均能保持在60cm以上,而对照组SD改变不明显,波动于29～40.3cm之间;多数时间内处理组水体的溶解氧(DO)含量都显著低于对照组,说明环棱螺的存在可直接或间接降低水体DO浓度.试验表明,单一投放螺类可有效降低藻华水体的叶绿素a(Chl-a)含量,但难以削减营养盐浓度.实验条件下,围隔水体总氮和正磷酸盐浓度的下降趋势均与螺的密度呈现负相关性(R=-0.9851,p<0.05;R=-0.9678,p<0.05);对SD、DO、pH、Chl-a、NH₄⁺-N、NO₃^--N、PO₄^3--P等7个主要理化指标数据进行了Duncan多重比较分析以及聚类分析,结果显示对照组和处理组在p<0.05水平上均存在显著差异,说明环棱螺的投放能在一定程度上调控水体质量.     

Genetic characterization of the resorcinol catabolic pathway in Corynebacterium glutamicum

Corynebacterium glutamicum grew on resorcinol as a sole source of carbon and energy. By genome-wide data mining, two gene clusters, designated NCgl1110-NCgl1113 and NCgl2950-NCgl2953, were proposed to encode putative proteins involved in resorcinol catabolism. Deletion of the NCgl2950-NCgl2953 gene cluster did not result in any observable phenotype changes. Disruption and complementation of each gene at NCgl1110-NCgl1113, NCgl2951, and NCgl2952 indicated that these genes were involved in resorcinol degradation. Expression of NCgl1112, NCgl1113, and NCgl2951 in Escherichia coli revealed that NCgl1113 and NCgl2951 both coded for hydroxyquinol 1,2-dioxygenases and NCgl1112 coded for maleylacetate reductases. NCgl1111 encoded a putative monooxygenase, but this putative hydroxylase was very different from previously functionally identified hydroxylases. Cloning and expression of NCgl1111 in E. coli revealed that NCgl1111 encoded a resorcinol hydroxylase that needs NADPH as a cofactor. E. coli cells containing Ncgl1111 and Ncgl1113 sequentially converted resorcinol into maleylacetate. NCgl1110 and NCgl2950 both encoded putative TetR family repressors, but only NCgl1110 was transcribed and functional. NCgl2953 encoded a putative transporter, but disruption of this gene did not affect resorcinol degradation by C. glutamicum. The function of NCgl2953 remains unclear.     

趋流行为下斑马鱼幼鱼的全脑成像

目的 趋流,意即在水中调整身体方向并逆流而上的能力,是一种在大多数鱼类与两栖类动物中存在的保守行为。虽然关于趋流的研究已有一段很长的历史,并且近年来斑马鱼幼鱼趋流行为的理论机制也被提出,但是分布式的神经环路是如何整合多感知信息、做出决策、并实现行为控制仍然是个未知数。对自由运动的斑马鱼进行全脑神经活动成像为理解这一困难的问题提供了特殊的机会。方法 本文开发了一种微流控装置精确控制环境水流并激发斑马鱼的趋流行为。将该微流控芯片与扩增视野光场显微镜以及追踪系统整合,从而记录自由行为下斑马鱼全脑的神经活动。结果 在整合的微流控装置中稳定观察到了斑马鱼在水流中保持自身位置不变、逆流而上等刻板的趋流行为现象。与此同时,实现了对斑马鱼幼鱼趋流行为过程中的全脑钙活动记录。本文初步发现了几个脑区的神经活动与趋流行为相关。结论 本研究第一次展示了在斑马鱼幼鱼趋流行为的同时记录全脑神经活动的技术。接下来对神经活动和行为数据的分析与建模将有助于更好地理解一种重要自然行为背后的感觉运动转换机制。     

Genetic Characterization of the Resorcinol Catabolic Pathway in Corynebacterium glutamicum

Corynebacterium glutamicum grew on resorcinol as a sole source of carbon and energy. By genome-wide data mining, two gene clusters, designated NCgl1110-NCgl1113 and NCgl2950-NCgl2953, were proposed to encode putative proteins involved in resorcinol catabolism. Deletion of the NCgl2950-NCgl2953 gene cluster did not result in any observable phenotype changes. Disruption and complementation of each gene at NCgl1110-NCgl1113, NCgl2951, and NCgl2952 indicated that these genes were involved in resorcinol degradation. Expression of NCgl1112, NCgl1113, and NCgl2951 in Escherichia coli revealed that NCgl1113 and NCgl2951 both coded for hydroxyquinol 1,2-dioxygenases and NCgl1112 coded for maleylacetate reductases. NCgl1111 encoded a putative monooxygenase, but this putative hydroxylase was very different from previously functionally identified hydroxylases. Cloning and expression of NCgl1111 in E. coli revealed that NCgl1111 encoded a resorcinol hydroxylase that needs NADPH as a cofactor. E. coli cells containing Ncgl1111 and Ncgl1113 sequentially converted resorcinol into maleylacetate. NCgl1110 and NCgl2950 both encoded putative TetR family repressors, but only NCgl1110 was transcribed and functional. NCgl2953 encoded a putative transporter, but disruption of this gene did not affect resorcinol degradation by C. glutamicum. The function of NCgl2953 remains unclear.     

篮状菌属的四个中国新记录种

在系统调查我国篮状菌属Talaromyces物种资源的工作中,分离得到了10株篮状菌。基于形态学和BenA、CaM及rDNA ITS1-5.8S-ITS2序列的分子种系学分析确定它们分属于6个种,即艾米斯托克篮状菌T. amestolkiae、暗玫瑰篮状菌T. atroroseus、暗绿篮状菌T. fuscoviridis、肯德里克篮状菌T. kendrickii、斯托尔篮状菌T. stollii和多样篮状菌T. versatilis,其中后4种为篮状菌组section Talaromyces的我国新记录种。T. fuscoviridis生长适中,在MEA培养基背面呈特征性的暗绿色,形成绒兼短絮状菌落,产生稀疏的灰色分生孢子,其帚状枝双轮生兼单轮生,瓶梗为安瓿形;T. kendrickii生长适中,产生典型绒状菌落和大量深绿色分生孢子,其帚状枝双轮生兼不规则生,排列紧密,瓶梗为安瓿形;T. stollii生长迅速,形成绒状兼絮状菌落并产生大量灰绿色分生孢子,其帚状枝双轮生兼三轮生,排列紧密,瓶梗为典型披针形;T. versatilis生长迅速,形成短絮状兼绳状菌落,产生脏粉色菌丝体和稀疏的灰色分生孢子,其帚状枝双轮生兼单轮生,排列不紧密,瓶梗为安瓿形。这4个新记录种的发现进一步丰富了我国篮状菌属的物种资源。     

Decreased circulating leptin and increased neuropeptide Y gene expression are implicated in food deprivation-induced hyperactivity in striped hamsters, Cricetulus barabensis

Physiological and behavioral adjustments of small mammals are important strategies in response to variations in food availability. Although numerous of studies have been carried out in rodents, behavioral patterns in response to food deprivation and re-feeding (FD–RF) are still inconsistent. Here we examined effects of a 24 h FD followed by RF on general activity, serum leptin concentrations and gene expression of orexigenic and anorexigenic hypothalamic neuropeptides in striped hamsters (Cricetulus barabensis) with/without leptin supplements. The time spent on activity was increased by 2.5 fold in FD hamsters compared with controls fed ad libitum (P < 0.01). Body mass, fat mass as well as serum leptin concentrations were significantly decreased in FD hamsters in comparison with ad libitum controls, which were in parallel with hyperactivity. During re-feeding, leptin concentrations increased rapidly to pre-deprivation levels by 12 h, but locomotor activity decreased gradually and did not return to pre-deprivation levels until 5 days after re-feeding. Leptin administration to FD hamsters significantly attenuated the increased activity. Gene expression of hypothalamic neuropeptide Y (NPY) was upregulated in FD hamsters and fell down to control levels when hamsters were re-fed ad libitum, similar to that observed in activity behavior. Leptin supplement induced increases in serum leptin concentrations (184.1%, P < 0.05) in FD hamsters and simultaneously attenuated the increase in activity (45.8%, P < 0.05) and NPY gene expression (35%, P < 0.05). This may allow us to draw a more generalized conclusion that decreased leptin concentrations function as a starvation signal in animals under food shortage; to induce an increase in activity levels, leading animals to forage and/or migrate, and consequently increasing the chance of survival. Decreased concentrations of serum leptin in animals subjected to food shortage may induce an upregulation of gene expression of hypothalamus NPY, consequently driving a significant increase in foraging behavior.