大麻哈鱼卵黄囊期仔鱼异速生长及其生态学意义

运用实验生态学的方法, 对大麻哈鱼(Oncorhynchus keta Walbaum)卵黄囊期仔鱼的异速生长及器官优先发育在早期生存和环境适应上的生态学意义进行了研究。结果表明, 大麻哈鱼卵黄囊期仔鱼的感觉、摄食, 呼吸和游泳等器官快速分化, 许多关键器官均存在异速生长现象。在身体各部分中, 头部和尾部为正异速生长, 躯干部为负异速生长, 体高有先增大后减小的趋势; 在头部器官中, 眼径、口宽、吻长和眼后头长均为正异速生长; 在游泳器官中, 胸鳍、腹鳍、背鳍、臀鳍、背鳍基、臀鳍基和尾鳍均为正异速生长, 脂鳍为负异速生长, 其中, 腹鳍在全长25.31 mm、12日龄出现生长拐点, 但拐点前后均为正异速生长。大麻哈鱼卵黄囊期仔鱼感觉、摄食, 呼吸和游泳等器官的快速发育, 使出膜后的仔鱼在最短的时间内获得了与早期生存密切相关的各种能力, 对适应复杂多变的外界环境具有重要的生态学意义。       

Pedigree‐based analysis of derivation of genome segments of an elite rice reveals key regions during its breeding

Analyses of genome variations with high‐throughput assays have improved our understanding of genetic basis of crop domestication and identified the selected genome regions, but little is known about that of modern breeding, which has limited the usefulness of massive elite cultivars in further breeding. Here we deploy pedigree‐based analysis of an elite rice, Huanghuazhan, to exploit key genome regions during its breeding. The cultivars in the pedigree were resequenced with 7.6× depth on average, and 2.1 million high‐quality single nucleotide polymorphisms (SNPs) were obtained. Tracing the derivation of genome blocks with pedigree and information on SNPs revealed the chromosomal recombination during breeding, which showed that 26.22% of Huanghuazhan genome are strictly conserved key regions. These major effect regions were further supported by a QTL mapping of 260 recombinant inbred lines derived from the cross of Huanghuazhan and a very dissimilar cultivar, Shuanggui 36, and by the genome profile of eight cultivars and 36 elite lines derived from Huanghuazhan. Hitting these regions with the cloned genes revealed they include numbers of key genes, which were then applied to demonstrate how Huanghuazhan were bred after 30 years of effort and to dissect the deficiency of artificial selection. We concluded the regions are helpful to the further breeding based on this pedigree and performing breeding by design. Our study provides genetic dissection of modern rice breeding and sheds new light on how to perform genomewide breeding by design.     

DIFFERENCES IN SEQUENCES OF RIBOSOMAL DNA SECOND INTERNAL TRANSCRIBED SPACER AMONG THREE MEMBERS OF ANOPHELES HYRCANUS COMPLEX FROM THE REPUBLIC OF KOREA

Abstract  Differences in sequences of ribosomal DNA second internal transcribed spacer (ITS) among Anopheles sinensis, An. lesteri and An. yatsushiroensis from Korea were compared. The PCR amplified rDNA-ITS2 fragments were sequenced directly. Three samples of each species were individually determined.
Lengths of the ITS2 regions were 468bp in An sinensis , 451bp in An lesteri and 453bp in An yatsushiroenesis and GC contents were 44.87 % 46.2 % and 45.7 % respectively. Variations of the sequences ranged from 12.16 % to 30.7 % among the three species. The differences of the rDNA-ITS2 sequences would be useful for molecular identification of the three members of Anopheles hycanus complex from Korea.     

Improvement of Sciatic Nerve Regeneration Using Laminin-Binding Human NGF-β

Background

Sciatic nerve injuries often cause partial or total loss of motor, sensory and autonomic functions due to the axon discontinuity, degeneration, and eventual death which finally result in substantial functional loss and decreased quality of life. Nerve growth factor (NGF) plays a critical role in peripheral nerve regeneration. However, the lack of efficient NGF delivery approach limits its clinical applications. We reported here by fusing with the N-terminal domain of agrin (NtA), NGF-β could target to nerve cells and improve nerve regeneration.

Methods

Laminin-binding assay and sustained release assay of NGF-β fused with NtA (LBD-NGF) from laminin in vitro were carried out. The bioactivity of LBD-NGF on laminin in vitro was also measured. Using the rat sciatic nerve crush injury model, the nerve repair and functional restoration by utilizing LBD-NGF were tested.

Findings

LBD-NGF could specifically bind to laminin and maintain NGF activity both in vitro and in vivo. In the rat sciatic nerve crush injury model, we found that LBD-NGF could be retained and concentrated at the nerve injury sites to promote nerve repair and enhance functional restoration following nerve damages.

Conclusion

Fused with NtA, NGF-β could bind to laminin specifically. Since laminin is the major component of nerve extracellular matrix, laminin binding NGF could target to nerve cells and improve the repair of peripheral nerve injuries.     

响应面法优化枯草芽孢杆菌产脂肪酶的合成培养基

对枯草芽孢杆菌(Bacillus subtilis)CICC20034利用合成培养基液体发酵产脂肪酶的条件进行了优化。首先采用单因子实验筛选出最适诱导剂为三丁酸甘油酯,氮源为尿素,碳源为葡萄糖,无机盐为MgSO4。在此基础上,利用Plackett-Burman设计对影响产酶因素的效应进行评价,筛选出具有显著效应的三丁酸甘油酯、尿素、KH2PO4和培养基起始pH值4个最显著的因素。用最陡爬坡路径逼近最大产酶区域后,利用响应面中心组合设计对显著因素进行优化,获得最适合成培养基组分为:葡萄糖8g/L,尿素8.57g/L,三丁酸甘油酯2.62%,KH2PO42.59g/L,MgSO4.7H2O0.5g/L,TritonX-1000.5g/L,pH9.47。优化后的B.subtilis CICC 20034胞外脂肪酶活力达0.483U/ml,比初始酶活力0.072U/ml提高了6.7倍。     

外加电场刺激对菲降解菌的影响

以菲为主要C源,吐温80作为增溶剂,研究细菌Enterobacter dissolvens在直流电和交流电条件下的生长和代谢过程。实验结果表明:当施加10 mA直流电时,通电8 h后,菌液中细胞的菲降解率较对照增长1.6倍,细胞生长亦有所加快;而施加交流电时,细菌生长和菲降解率均低于直流电刺激。     

不同林龄刺槐叶功能性状差异及其与土壤养分的关系

对不同林龄刺槐群落叶功能性状差异及其与土壤养分的关系进行研究,分析刺槐对黄土丘陵区土壤环境的适应策略.结果表明: 随林龄的增大,刺槐比叶面积、叶面积、叶片含水量、叶全氮含量及叶有机碳含量呈先增大后减小的变化趋势,且在30年林龄时达到最大值,分别为279.18 cm²·g^-1、12.33 cm²、0.09%、33.01 g·kg^-1、523.08 g·kg^-1.随林龄的增大,叶组织密度、叶全磷含量、叶厚度及气孔密度呈增大趋势,气孔长度及气孔宽度呈减小趋势.主成分分析表明,叶面积、比叶面积、叶全磷含量、叶片含水量、叶厚度及气孔密度均为刺槐叶功能性状随林龄变化的主要指标.各指标间呈一定的相关性,这表明刺槐能改变自身的形态结构,形成最佳功能组合以适应环境的变化.影响叶面积、叶片含水量、比叶面积及气孔长度的主要土壤因子是土壤全氮含量,影响气孔宽度、叶组织密度、叶厚度、叶全磷含量、叶全氮含量及气孔密度的主要土壤因子是土壤有机碳含量,这表明土壤全氮含量和有机碳含量是影响不同林龄刺槐叶功能性状的主要土壤因子.随林龄的增大,刺槐群落土壤养分得到改善,进而影响刺槐叶功能性状.不同林龄刺槐叶功能性状的差异反映出刺槐具有较强的叶片形态可塑性,有利于其适应黄土丘陵区的土壤环境.     

Synthesis and biological evaluation of 9-fluorenone derivatives for SPECT imaging of α7-nicotinic acetylcholine receptor

The α7-nicotinic acetylcholine receptor (α7-nAChR) subtype, is found to have a connection with the pathogenesis of a variety of psychiatric and neurological disorders. Herein, we report the development of radioiodinated 9-fluorenone derivatives as single-photon emission computed tomography (SPECT) imaging tracers for α7-nAChRs. Among the derivatives, the best member of the series 10 (Ki = 2.23 nM) were radiolabeled with ¹²⁵I for in vitro and in vivo studies. The radiotracer [¹²⁵I]10 exhibited robust brain uptake and specifically labeled α7-nAChRs with a peak uptake value of 9.49 ± 0.87%ID/g in brain. Blocking studies demonstrated that the tracer was highly specific toward α7-nAChR. Furthermore, ex vivo autoradiography and micro-SPECT/CT dynamic imaging in mice confirmed the excellent imaging properties. In addition, molecular docking was also performed to rationalize the potency of the chosen compounds towards α7-nAChRs. To conclude, compound 10 could serve as a promising radiotracer for the α7-nAChRs.     

含有Rubisco小亚基启动子和转运肽序列的通路克隆入门载体的构建和应用

Gateway(通路克隆)技术是最近开发出来的一种分子克隆技术,其特点是操作简单、省时高效,已经成功应用于很多基因表达载体的构建.然而,现有的通路克隆植物表达载体不包含任何将表达蛋白定位到叶绿体中的序列.将通路克隆入门质粒载体pENTR-2B的XmnⅠ位点改造成HindⅢ位点,产生入门载体pENTR*-2B,然后将番茄1,5二磷酸核酮糖羧化酶(Rubisco)小亚基3C的启动子(PrbcS)及其转运肽序列(*T)和绿色荧光蛋白(GFP)报告基因亚克隆到pENTR*-2B中,构建通路克隆入门载体pENTR*-PrbcS-*T-GFP.实验结果证实,用pENTR*-PrbcS-*T-GFP和通路克隆的植物表达载体进行LR反应,构建GFP的光诱导型植物表达载体,可以成功地将表达的GFP定位到转基因植物的叶绿体中.利用β-葡糖苷酸酶(GUS)报告基因替代该入门载体中的GFP基因做试验也得到相似的结果.这说明用目的基因替换该入门载体中的GFP可以构建目的基因的入门载体,然后用通路克隆技术可以快速构建其光诱导型植物表达载体,将表达的目的蛋白定位到转基因植物或组织细胞的叶绿体中.     

儿童癫痫的围产期高危因素分析

目的：研究儿童癫痫相关的国产期高危因素。方法：随访16986例新生儿后期癫痫的患病情况,分为儿童癫痫组与非癞痫组,比较两组各项围产期高危因素,进行单因素与多因素统计分析。结果：随访期内儿童癫痫的发病例数为118例（6．95‰）,癫痫的发病率在1岁以下的儿童最高（27．12％）。儿童癫痫的发生与孕周、高龄产妇、低出生体重、流产史、宫内窘迫、喂养方式、孕期感染、子痫、胎盘早剥、新生儿惊厥都有相关性,并且孕周、子痫和新生儿惊厥是儿童癫痫发生的独立危险因素。结论：儿童癫痫的发生与围产期高危因素密切相关,这对临床儿童癫痫的诊疗可能有提示作用。