云南松SSR-PCR反应体系的建立与优化

为了建立适宜云南松SSR-PCR的反应体系和扩增程序,利用近缘种火炬松的引物,采用正交设计L16(45)对云南松SSR-PCR反应体系的5因素(Taq酶、Mg2+、模板DNA、dNTP、引物)在4个水平上进行优化,筛选出各反应因素的最佳水平,建立了适于云南松的SSR反应体系.在10μL的反应体系中,模板DNA的用量为30.0 ng,Taq DNA聚合酶的用量为1.0 U,Mg2+的浓度为2.0 mmol/L,dNTPs浓度为0.4 mmol/L,引物的浓度为0.2 μmol/L.扩增程序为:94℃预变性4 min;94℃变性45 s,48℃退火30 s,72℃延伸30 s,30个循环;72℃延长10 min,4℃保存.最后利用1个居群对该体系进行稳定性验证,结果可用于云南松SSR标记的研究.     

正交试验优化八角ISSR-PCR反应体系

利用正交试验设计研究Taq DNA聚合酶、DNA模板、引物(UBC 886)、dNTP、Mg2+浓度5个因素对云南八角ISSR-PCR反应的影响,建立其最佳反应体系。结果表明:25μL的反应体系中5个因子的最佳水平为:Mg2+3 mmol/L、Taq DNA聚合酶0.5 U、DNA模板0.016 ng、引物0.8μmol/L、dNTPs 0.2 mmol/L。PCR最佳反应程序为:94℃预变性5 min;94℃变性30 s,46℃退火45 s,72℃延伸1 min,40次循环;72℃最后延伸7 min,4℃保存。     

黑籽南瓜ISSR-PCR反应体系的正交设计优化

以云南个旧黑籽南瓜叶片基因组DNA为模板,固定反应程序,采用L_(16)(4~5)正交试验设计的方法,对影响ISSR-PCR反应的五因素(dNTPs,Mg~(2+),引物,Taq DNA聚合酶,模板DNA)在四个水平上进行优化试验。研究建立起了适于云南黑籽南瓜ISSR-PCR的最佳反应体系:25μl反应体系中含10×buffer 2.5μl、0.15mmol/L dNTPs、2.5mmol/L Mg2+、0.40μmol/L引物、1.5U Taq DNA聚合酶、DNA模板15ng。扩增程序为:95℃预变性5min,94℃变性45s,52℃退火45s,72℃延伸90s,进行35个循环,最后72℃延伸7min。该优化体系的建立为今后用ISSR标记技术进行黑籽南瓜种质资源的分类鉴定和遗传多样性研究奠定了基础。     

均匀设计优化建兰ISSR-PCR体系

采用均匀设计,对影响建兰ISSR-PCR体系的引物、Mg^2＋、dNTP和Taq DNA聚合酶浓度等进行4因素5水平和4因素3水平两轮优化,建立了适合于建兰ISSR-PCR的反应体系：在20μL反应体系中,舍引物0．25μmol／L、Mg^2＋ 2．5mmol／L,dNTP0．2mmol／L、Taq DNA聚合酶1.5U和模板DNA40ng．在此基础上对扩增程序中的循环次数和退火温度,以及ISSR引物进行筛选．筛选获得的扩增程序为：94℃预变性5min;接着进行32个循环：94℃变性35S,52～56℃退火45S,72℃延伸90s;循环结束后,72℃延伸10min．同时筛选得到14个扩增稳定、多态性丰富的ISSR引物．     

栝楼ISSR-PCR体系的正交优化

目的：建立栝楼最佳ISSR-PCR正交优化体系,为开展栝楼ISSR分子标记奠定技术基础。方法：采用正交试验设计对影响栝楼ISSR-PCR扩增的重要参数（DNA模板、MgCl2、dNTPs、引物、TaqDNA聚合酶）进行优化试验,同时进行不同温度梯度试验和ISSR体系筛选。结果：最佳的栝楼ISSR-PCR的反应体系（20μl）为：30ng模板DNA,2.0mmol/L MgCl2,0.3mmol/L dNTPs,0.5μmol/L引物,0.5U Taq DNA聚合酶;退火温度为52℃-55℃;扩增反应程序为：94℃预变性5min;94℃变性30s,52℃退火1min,72℃延伸2min,35个循环;72℃延伸7min;4℃保存。结论：建立了栝楼的最佳ISSR反应体系,为栝楼种质鉴定提供了更客观可靠     

冬瓜和节瓜DNA提取及RAPD反应体系优化

以8份冬瓜和节瓜为材料,采用改良CTAB法提取基因组DNA,采用正交试验设计,对冬瓜和节瓜RAPD条件进行了优化,建立了最佳反应体系:25μL反应体系中含1×buffer,模板DNA、Mg2+、dNTPs、引物和Taq酶的浓度分别为20 ng、2.0mmol/L、0.24 mmol/L、0.3μmol/L和1.0 U。PCR扩增程序为:94℃预变性5 min;94℃变性45 s,36.9℃退火45 s,72℃延伸1.5min,共40个循环;72℃延伸10 min,12℃保存。     

花椰菜温敏型雄性不育系的RAPD标记

选取温敏花椰菜不育系GS-19与GS-31杂交组合的F2高可育和高不育单株构建基因池,利用100对随机引物对其进行RAPD标记。同时,采用正交设计对其反应体系及扩增条件进行优化。试验结果表明,在25μL反应体系中含dNTPs0.625mmol/L,引物0.5μmol/L,DNA模板60ng,Taq酶1.5U,超纯水14.9μL;反应条件为94℃预变性4min,然后进行94℃变性30s,36℃退火45s,72℃延伸90s,35个循环后,再72℃延伸7min,花椰菜RAPD扩增效果较好。P21-1800为花椰菜温敏雄性不育基因的连锁标记。     

草鱼TRAP-PCR反应体系的建立

目的:通过优化草鱼TRAP-PCR反应体系,将新型分子标记-靶位区域扩增多态性(target region amplified polymorphism,TRAP)引用到草鱼遗传多样性研究中。方法:以草鱼DNA为材料,分析了模板DNA、Mg2 、dNTPs、引物浓度,以及循环参数、退火温度对TRAP-PCR扩增结果的影响。结果:确立了稳定性强、重复性好的草鱼TRAP-PCR最佳反应体系和扩增参数:在25μl的PCR反应体系中,含约50ng模板DNA,1UTaq酶,1×PCR缓冲液,2.0mmol/L MgCl2,4种dNTPs各0.2mmol/L,固定引物与随机引物各15pmol;首先使模板在94℃变性3min;然后94℃变性1min,38℃退火1min,72℃延伸lmin进行5个循环;接着94℃变性45s,55℃退火45s,72℃延伸lmin再进行35个循环,最后72℃延伸7min。结论:TRAP-PCR反应体系稳定可靠,该新型分子标记可应用于草鱼遗传多样性研究中。     

长心卡帕藻RAPD-PCR反应体系的正交优化研究

采用SDS(十二烷基硫酸钠,20%)法提取了大型海藻长心卡帕藻(Kappaphycus alvarezii)基因组DNA.通过单因子梯度试验,确定了影响随机扩增DNA多态性(RAPD)扩增结果的模板、Mg2 、dNTPs、S22引物、Taq的适宜浓度、退火温度和反应的最佳循环次数;利用正交试验优化了模板、Mg2 、dNTPs、S22引物、Taq的配比浓度.结果表明,在进行长心卡帕藻的RAPD扩增时,在总体积为25μl的反应体系中,模板、Mg2 、dNTPs、S22引物、Taq的最佳浓度分别为15ng、2.0mmol/L、0.2mmol/L、0.25μmol/L、2.5U;退火温度为37℃.反应程序为94℃预变性5min,然后经94℃变性30s、37℃退火1min.72℃延伸2min,进行30次循环,最后在72℃再延伸10min.     

正交设计优化绿竹ISSR-PCR体系和引物筛选

旨在建立绿竹ISSR-PCR最佳反应体系和扩增程序,并筛选适于绿竹ISSR-PCR分析的高多态性引物。以绿竹基因组DNA为ISSR-PCR扩增模板,采用正交试验方法,对d NTPs浓度、Mg2+浓度、Taq DNA聚合酶浓度、引物浓度、模板DNA用量设计5因素4水平试验,采用极差分析法和方差分析法对试验结果进行分析。并对退火温度和循环次数进行筛选,建立绿竹ISSR-PCR最佳反应体系和扩增程序。并利用优化后的体系对100条ISSR引物进行筛选。最终确定的最佳反应体系为:20μL的扩增体系中,d NTPs浓度为0.2 mmol/L,Mg~(2+)浓度为2.0 mmol/L,Taq DNA聚合酶浓度为1.5 U,引物浓度为0.4μmol/L,DNA浓度为60 ng,10×PCR Buffer体积为2μL、剩下用灭菌ddH_2O补全。各因素影响大小依次是:Mg~(2+)d NTPs模板DNATaq DNA聚合酶引物。扩增程序为:94℃预变性5 min;94℃变性45 s,(根据引物的退火温度)复性30 s,72℃延伸90 s,循环38次,72℃延伸10 min,4℃保存。以此体系为基础进行引物筛选,在100条ISSR引物中筛选出14条扩增条带清晰、多态性较高、重复性好的引物。     

音乐治疗效应的动物实验研究

近年来国内外关于音乐治疗效应的动物实验研究认为：音乐能影响动物的情绪;音乐还对动物的免疫功能、学习及记忆能力、以及动物的神经系统结构和功能等均有一定影响。该领域的研究有利于深入探索音乐疗法的作用机理。     

Time on task effects on safety

Reviewing the literature on time on task effects on safety shows contradictory evidence, especially with regard to 12 h shifts. It is argued that this might depend on methodological problems associated with the analysis of accident data, e.g. selectivity of samples, validity of data bases and study designs, especially for analyses at the company level. Analyses of aggregated data seem to indicate an exponential increase of accident risk with time on task beyond the normal working day. This is supported by some recent studies based on data from the Federal Republic of Germany.     

Perspectives on hair evolution based on some comparative studies on vertebrate cornification

Hair evolution contributed to the biological success of mammals. Hair origin from synapsid scales is speculative and requires extensive modifications of the morphogenetic process transforming lens-shaped dermis of scales into small dermal papillae in hair. Hair evolution from glands is hypothetical but is supported from studies on the signaling control of hair vs. glandular morphogenesis. Based on immunocytochemical and comparative studies, it is hypothesized that the onion-like organization of hair derived from glandular pegs which central part produced lipids and some keratin. In a following stage, involucrin, trichohyalin, and keratins were produced in the central cells of the gland and formed a solid medulla surrounded by keratinocytes of the inner root sheath. The origin of this protohair was possibly related to increased concentration of beta-catenin and other signaling molecules in epithelial cells following the evolution of a dermal papilla. The latter activated the keratogenic genes, already utilized in cells of the claws, in concentric layers of cells of the glandular peg. Lipidogenic genes were depressed. As new genes evolved in the genome of synapsids, new circular layers of keratinocytes containing specialized hard keratins and keratin-associated proteins were formed around medullary cells. The new keratinocytes probably originated the cortex separating medulla from the external cells that became the inner root sheath. The hypothesis indicates that in a following stage, the medulla was obliterated or replaced by cortical cells while the external part of the cortex formed a cuticular surface due to the different growth rate with inner root sheath cells.     

Studies on Biosynthesis on Biotin by Microorganisms

The accumulation of biotin-vitamers in the culture media of a large number of microorganisms (about 700 strains) was studied. The contents of the biotin-vitamers were quantitatively determined by microbiological assays with Lactobacillus arabinosus and Saccharomyces cerevisiae.

It was found that large amounts of biotin-vitamers were accumulated by various microorganisms such as Streptomyces, molds and bacteria, and that the yield of biotin-vitamers was enhanced by the addition of pimelic acid or azelaic acid to the media. It was also found that the main portion of the vitamers accumulated by many microorganisms did not support the growth of Lactobacillus arabinosus, while it did support that of Saccharomyces cerevisiae. The small amounts of true biotin were observed in the culture media of various Streptomyces and molds, but hardly in the culture media of bacteria.

The identification of biotin-vitamers accumulated by various microorganisms is described, and the distribution of the vitamers in microorganisms is also described.

The results presented in this paper show that the main component of the vitamers accumulated by many microorganisms is identified as desthiobiotin by anion exchange column chromatography, paper chromatography and chemical analysis. Small amounts of fraction B (unidentified vitamers) and Fraction D (biotin) were also detected in the culture media of various molds and Streptomyces. However, these fractions were not observed in the culture media of any bacteria tested.

It was also found that large amounts of an unknown biotin-vitamer was accumulated by various bacteria. The vitamer was avidin-uncombinable, and, from the paper electrophoretic studies, it was assumed that the vitamer might be an analogue of pelargonic acid.