梅花鹿GHR基因完整编码区序列生物信息学分析

为了研究梅花鹿生长激素受体基因的结构和功能,从GenBank中下载梅花鹿、牛、山羊、猪、北极狐、大熊猫、人、猕猴、小鼠、大鼠、鸡、家鹅、绿头野鸭及金鱼的生长激素受体基因完整编码区及氨基酸序列,对梅花鹿与其他13个物种生长激素受体基因的完整编码区及其编码氨基酸序列进行相似性比对,并基于氨基酸序列构建系统进化树,利用BioEdit 7.0等软件对梅花鹿生长激素受体基因的碱基组成及其编码蛋白的理化性质和结构特征进行生物信息学分析。结果表明,梅花鹿与山羊、牛的生长激素受体基因氨基酸序列相似性较高,亲缘关系最近;梅花鹿生长激素受体基因完整编码区长度为1 905bp,编码634个氨基酸,A+T含量高于G+C;其编码的蛋白是一种分子质量为70.927 8ku、等电点为4.56的疏水性不稳定酸性蛋白;该蛋白含有1个信号肽,属于一种分泌型蛋白;存在1个强跨膜区、36个广泛磷酸化位点,二级结构元件以无规则卷曲为主。研究结果可为梅花鹿生长激素受体基因的进一步分析提供详细的生物信息学基础资料。     

鹿、牛基因组不同区域的微小变异研究

本研究借助鹿和牛基因组序列,通过同源序列比较的方法研究远缘物种基因组不同区域的微小变异,包括单碱基突变、小片段插入和删除.研究结果验证了基因组功能区的点突变和删除变异相对非功能区是保守的普遍性结论.点突变变异与删除变异在鹿、牛基因组不同区域上表现强的正相关性.比较近缘物种人、黑猩猩基因组点突变变异数据,表明牛、鹿基因组的功能区和非功能区突变速率各自保持大致恒定,符合分子钟理论     

清水池塘吊水饥饿处理对大口黑鲈品质的提升效果

为了研究吊水饥饿处理对土塘养殖大口黑鲈（Micropterus salmoides）鱼肉品质的提升效果,本研究在种植苦草(Vallisneria spiralis)的清水池塘中,比较了不同暂养时间下（0、1、4、7、10、13、16 d）,鱼肉的营养成分、质构特性和土腥味物质的变化情况。结果发现,暂养不同时间后：（1）大口黑鲈鱼肉的水分含量显著下降至74.90±2.40%（第7 d）,灰分含量显著上升,达到1.27±0.17%（第7 d）;总糖含量先下降,后恢复至初始含量水平0.49±0.03 g/100 g（第13 d）。（2）鱼肉中不饱和脂肪酸新增加3种（C20:3n3、C20:4n3、C22:4n6）,总脂肪酸达到23种（第10 d）;游离氨基酸有16种,氨基酸滋味活性值（taste active value,TAV）随着暂养时间延长有显著变化（P<0.05）,其中具有鲜味的谷氨酸TAV>1（第4 d）,呈苦味的组氨酸TAV<1（第16 d）。（3）暂养10 d后,鱼肉硬度和咀嚼性显著增加（P<0.05）。（4）鱼肉中土腥味物质2-MIB和GSM含量分别由开始的0.42±0.01 μg/Kg和0.54±0.06 μg/Kg下降到0.33±0.05 μg/Kg、0.35±0.06 μg/Kg（第16 d）。本研究表明清水池塘暂养处理能显著改善大口黑鲈的鱼肉品质,综合提升效果和经济效益,暂养时间为10 d较好。     

Simulating hydrological responses to climate change using dynamic and statistical downscaling methods: a case study in the Kaidu River Basin,Xinjiang, China

Climate change may affect water resources by altering various processes in natural ecosystems. Dynamic and statistical downscaling methods are commonly used to assess the impacts of climate change on water resources. Objectively, both methods have their own advantages and disadvantages. In the present study, we assessed the impacts of climate change on water resources during the future periods (2020-2029 and 2040-2049) in the upper reaches of the Kaidu River Basin, Xinjiang, China, and discussed the uncertainties in the research processes by integrating dynamic and statistical downscaling methods (regional climate models (RCMs) and general circulation modes (GCMs)) and utilizing these outputs. The reference period for this study is 1990-1999. The climate change trend is represented by three bias-corrected RCMs (i.e., Hadley Centre Global Environmental Model version 3 regional climate model (HadGEM3-RA), Regional Climate Model version 4 (RegCM4), and Seoul National University Meso-scale Model version 5 (SUN-MM5)) and an ensemble of GCMs on the basis of delta change method under two future scenarios (RCP4.5 and RCP8.5). We applied the hydrological SWAT (Soil and Water Assessment Tool) model which uses the RCMs/GCMs outputs as input to analyze the impacts of climate change on the stream flow and peak flow of the upper reaches of the Kaidu River Basin. The simulation of climate factors under future scenarios indicates that both temperature and precipitation in the study area will increase in the future compared with the reference period, with the largest increase of annual mean temperature and largest percentage increase of mean annual precipitation being of 2.4°C and 38.4%, respectively. Based on the results from bias correction of climate model outputs, we conclude that the accuracy of RCM (regional climate model) simulation is much better for temperature than for precipitation. The percentage increase in precipitation simulated by the three RCMs is generally higher than that simulated by the ensemble of GCMs. As for the changes in seasonal precipitation, RCMs exhibit a large percentage increase in seasonal precipitation in the wet season, while the ensemble of GCMs shows a large percentage increase in the dry season. Most of the hydrological simulations indicate that the total stream flow will decrease in the future due to the increase of evaporation, and the maximum percentage decrease can reach up to 22.3%. The possibility of peak flow increasing in the future is expected to higher than 99%. These results indicate that less water is likely to be available in the upper reaches of the Kaidu River Basin in the future, and that the temporal distribution of flow may become more concentrated.     

火龙果HpNAC1转录因子的特性分析及其对HpCytP450-like1基因的调控

以红肉火龙果(Hylocereus polyrhizus)果实为材料,克隆得到HpNAC1基因,研究该基因的荧光定量、亚细胞定位、转录活性及其对下游靶基因的调控能力,揭示其在火龙果生长发育过程中的分子作用机制。应用预测软件对HpNAC1基因进行生物信息学分析,利用q RT-PCR分析HpNAC1基因在果实发育过程中的表达情况,以农杆菌侵染烟草叶片的方法对HpNAC1基因进行亚细胞定位分析,以双荧光素酶瞬时表达的方法分析HpNAC1基因的转录活性及其对下游靶基因调控能力。结果表明,HpNAC1的ORF全长为846 bp,具有NAC结构域,q RT-PCR检测表明随着果实的生长发育,其表达明显增强;亚细胞定位和转录活性分析显示其是核蛋白,并且具有转录激活活性;双荧光素酶瞬时表达分析显示,HpNAC1转录因子可以激活基因Hp Cyt P450-like1的启动子活性。实验明确了HpNAC1基因的亚细胞定位信息及其在果实发育过程中表达和瞬时表达情况,为进一步研究其功能及分子机制提供依据。      

不同苜蓿品种种子发芽对盐胁迫的响应

[目的]针对内蒙古西部地区草地土壤盐碱化,选择盐碱土壤的主要成分NaCl和Na_2SO_4配成混合盐溶液进行室内发芽试验,筛选适合当地种植的耐盐苜蓿品种,为内蒙古西部盐碱草场的苜蓿种植提供理论依据。[方法]将NaCl和Na_2SO_4按摩尔浓度1∶1,用蒸馏水配成含盐量0.0%,0.2%,0.4%,0.6%,0.8%,1.0%,1.2%,1.4%,1.6%,1.8%,2.0%共11个梯度盐溶液,对25个苜蓿品种进行发芽试验,测定种子发芽率、相对发芽指数、种子相对简易活力指数,进行耐盐类型的划分。[结果]轻度盐分胁迫(0.2%和0.4%盐浓度)促进了苜蓿种子发芽,提高了种子的发芽率、相对发芽指数、种子相对简易活力指数;不同苜蓿品种间种子发芽的适宜盐浓度、半致死浓度、极限浓度差异较大。多数苜蓿品种的种子发芽适宜盐浓度是0.0%~0.6%,半致死盐浓度为0.8%,中草3号高达1.4%;极限盐浓度在1.0%~2.0%。[结论]综合聚类分析和种子发芽指标的表现得出,中草3号、新苜2号品种表现出较强的耐盐性,属于耐盐品种,magnumV-wet、赤草1号耐盐性较差,属盐敏感品种     

Research Progress on Prevalence of Horse Gastric Myiasis

Horse gastric myiasis is a chronic wasting parasitosis caused by larvae of Gasterophilus spp. parasitics on the gastrointestinal tract of the equids. Horse gastric myiasis leads to host highly anaemic, angular, poisoning even death. This disease is distributes all over the world, each country has a slightly different epidemic law, because of different geographical position and climatic environment, and whether using insect repellent or not. Our country is mainly popular in the Northeast, Northwest and Inner Mongolia, which of 6 kinds of popular horse Gastrophilus, and the dominant species are G. intestinalis and G. nasalis. In this paper,the author described the infections of horse gastric myiasis at home and abroad in recent years, summarized epidemic law and put forward the research direction, so as to provide reference for the disease prevention and control.     

Cryopreservation of Nili‐Ravi buffalo (Bubalus bubalis) semen in AndroMed® extender; in vitro and in vivo evaluation

The study was designed to evaluate AndroMed^® for the freezability and fertility of Nili‐Ravi buffalo semen. Semen was collected from four adult Nili‐Ravi buffalo (Bubalus bubalis) bulls for 3 weeks (replicate). Semen ejaculates from each buffalo bull were divided into three aliquots. One aliquot was used for evaluation of motility, plasma membrane integrity, livability, viability, DNA integrity and normal apical ridge. Remaining two aliquots were diluted (37°C; 50 × 10⁶ spermatozoa/ml) in tris‐citric egg yolk or AndroMed^® extender and cryopreserved in 0.5 ml French straws. After thawing, per cent post‐thaw motility (47.9 ± 0.8, 49.2 ± 1.7), plasma membrane integrity (44.4 ± 1.2, 46.8 ± 1.8) and normal apical ridge (81.4 ± 0.3, 83.2 ± 0.3) were recorded similar (p > .05) in tris‐citric egg yolk and AndroMed^® extender. Higher (p < .05) percentage of sperm livability (70.5 ± 1.4 and 64.4 ± 1.0), viability (67.5 ± 1.5 and 61.5 ± 0.6) and DNA integrity (97.0 ± 0.3 and 93.4 ± 0.21) were recorded in AndroMed^® compared to tris‐citric egg yolk post‐thaw. Values for all the aforementioned spermatozoal quality parameters were observed lower (p < .05) in frozen‐thawed compared to fresh semen irrespective of the experimental extenders. Fertility rates of buffalo semen did not differ (p > .05) either cryopreserved in tris‐citric egg yolk or AndroMed^® extender (45.5% vs. 49%). It is concluded that AndroMed^® is capable in protecting the buffalo bull sperm during freeze‐thawing process and can be adopted safely for routine use replacing the tris‐citric egg yolk extender in artificial insemination programme.     

Extracellular matrix in epitheliochorial,endotheliochorial and haemochorial placentation and its potential application for regenerative medicine

A placenta is defined as structural approximation of maternal and foetal tissues to perform physiological exchange. Associated processes of differentiation and the establishment of its cells take place within the extracellular matrix (ECM) that provides a rich environment of collagens, fibronectins, cytokines and other components. Placental ECM is promising for tissue regeneration purposes, because it has immune tolerance capacities that may cause only minimal rejections of transplants with immunological differences between donor and recipient. However, specific characteristics of ECM during evolution of the structurally very diverse mammalian placenta are not yet revealed. We here address the major aspects of placental types, that is non‐invasive (epitheliochorial), medium (endotheliochorial)‐to‐high (haemochorial) invasive nature of the interhemal barrier between the foetal and maternal blood system as well as their main components of ECM with special reference to species that are commonly used as animal models for human placentation and in the potential applications for regenerative medicine.     

酸性纤维素酶对壳聚糖的降解作用研究

为确定特定酸性纤维素酶在降解壳聚糖制备壳寡糖的应用潜力,根据不同作用条件下壳聚糖的水解率,考察该纤维素酶降解壳聚糖的基本条件,具体结果为酶解温度50℃、pH 5.0、酶解时间4 h、纤维素酶用量为0.7 mL。在确定的最佳酶解条件下,考察了酶解过程中壳聚糖溶液粘度的变化,同时通过有机溶剂分级沉淀法,对纤维素酶降解壳聚糖的最终产物进行分析,发现最终产物中聚合度(DP)<8和8相似文献