两种玻璃化胚胎冷冻方法对不同品系小鼠胚胎冷冻效果比较

目的探讨EFS和DAP两种玻璃化冷冻方法对不同品系小鼠胚胎冷冻的效果。方法6个品系小鼠（KM、ICR、BALB／c、C57BL／6J、OB／OB、LAP／~TAOF59）的2-cell胚胎分别用EFS和DAP两种玻璃化冷冻方法进行冷冻和复苏,比较两种冷冻方法的胚胎复苏率和着床率。结果6个品系小鼠冷冻胚胎EFS方法的平均复苏率为69．97％（47．9％～83．6％）,DAP方法的平均复苏率47．23％（26．3％-76．7％）,EFS方法明显优于DAP方法。其中KM、ICR和BALB／c小鼠EFS方法的冷冻复苏率显著高于DAP方法（P〈0．01）;冻融胚胎移植后EFS方法的平均着床率27．23％（1．75％一45．0％）,DAP方法的平均着床率31．43％（7．0％一46．3％）。除KM、ICR小鼠外,其他4个品系小鼠的着床率DAP方法高于EFS方法。结论KM和ICR远交群小鼠胚胎适合用EFS方法冷冻保存;C57BL／6J、OB／OB、LAP／aTAOF59三个品系小鼠DAP方法优于EFS方法,但差异不大;BALB／c小鼠两种玻璃化冷冻方法的冻融胚胎着床率均较低,需进一步研究。     

Microbial succession in the traditional Chinese Luzhou-flavor liquor fermentation process as evaluated by SSU rRNA profiles

The community succession of microbes inhabited in the fermenting lees of Luzhou-flavor liquor was investigated based on small-subunit rRNA culture independent method. All sequences recovered from fermenting lees respectively fell into the genera of Lactobacillus, Streptococcus, Bacillus, Staphylococcus, Clostridium, Pelobacter, Actobacter, Serratia, Burkholderia, Rhodoccous, Corynebacterium, Arthrobacter, Microbacterium, Curtobacterium, Leptotrichia, Methanocuuleus, Saccharomyces, Zygosaccharomyces, Saccharomycopsis, Pichia, Talaromyces, Aspergillus, Eurotium, Fomitopsis and Trichosporon. The fungal Pichia, Saccharomycopsis and Talaromyces were most abundant in the lees fermented for 1 day, the fungal Eurotium and the bacteria Burkholderia, Streptococcus and Lactobacillus were dominant in the lees fermented for 7 days, only the bacteria Lactobacillus, Burkholderia were prevalent in the lees fermented for 60 days. Most genera almost existed in the fermenting lees, while their distributions were significantly different in 1, 7 and 60 days fermented lees. The prokaryotic community similarity coefficient was from 0.5000 to 0.5455 and followed to 0.1523, and that of eukaryotic community was from 0.5466 to 0.5259 and to 0.3750 when compared at species level. These results suggested that many microbes in lees have community successions associated with fermenting and that such successions maybe contribute the fermentation process of Luzhou-flavor liquor and is main reasons that the characteristic flavor factors are produced.     

Histochemical Studies of the Non‐Host Resistance and the Role of Actin Cytoskeleton in Pepper Against Colletotrichum orbiculare

The penetration process and defence reactions (hypersensitive response, oxidative burst and cell wall fortification) of Colletotrichum orbiculare were studied histochemically on pepper cultivar ‘A11’ (non‐host) and susceptible cucumber cultivar ‘Changchun Thorn’ (host). The results indicate that C. orbiculare could hardly penetrate the non‐host pepper leaves. It was papillae rather than hypersensitive response and H₂O₂ that played an important role in resisting the colonization and development of C. orbiculare on the non‐host pepper. The depolymerization of the actin microfilament weakened the papilla deposition of pepper and allowed successful penetration of the non‐adapted C. orbiculare, suggesting that the actin cytoskeleton of pepper is significant in preventing the invasion of the non‐host pathogen C. orbiculare.     

Neural Response Phase Tracks How Listeners Learn New Acoustic Representations

1. Download : Download high-res image (286KB)
2. Download : Download full-size image

     

Vero细胞和脊髓灰质炎病毒在无血清条件下的培养探究

目的：探索Vero细胞和脊髓灰质炎病毒在无血清条件下的最佳培养条件,为无血清培养Vero细胞生产脊髓灰质炎疫苗奠定基础。方法选择直接适应（直降组）和序贯适应（驯化组）两种无血清培养方法,观察Vero细胞和脊髓灰质炎病毒在无血清条件下的生长情况,并检测脊髓灰质炎病毒及其病毒滴度。结果 Vero细胞在两种无血清条件下均生长良好,其中驯化组细胞生长速度更接近对照组。以脊髓灰质炎病毒Sabin株Ⅰ型分别感染直降组、驯化组和对照组细胞的病毒滴度平均值分别为8．94、8．81和8．94 LgCCID50/mL;Ⅱ型病毒滴度平均值分别为8．84、8．25和7．94 LgCCID50/mL;Ⅲ型病毒滴度平均值分别为8．91、8．57和8．63 LgCCID50/mL;且3组的变异系数（ CV）均小于10％。结论 Vero细胞在无血清条件下生长良好,无血清培养的Vero 细胞可用作脊髓灰质炎疫苗生产的基质。     

青海湖裸鲤三磷酸甘油醛脱氢酶基因的克隆和表达特性

目的开展青海湖裸鲤基础生物学特征和适应低氧、低温、高盐度的分子机理的研究,揭示青海湖裸鲤的基本生命活动规律,为该鱼种的资源保护和人工增殖放流提供理论依据。方法通过RT—PCR和RACE技术,得到了青海湖裸鲤三磷酸甘油醛脱氢酶（Gp—GAPDH）两种旁系同源体的完整编码序列,分别命名为Gp-GAPDHα（JX287372）和Gp-CAPDHβ（JX287373）。通过半定量RT-PCR分析白．GAPDHa和Gp-GAPDHβ在不同的组织和胚胎发育不同阶段的表达量。结果Gp—GAPDH两种异形体蛋白质序列的同源性为72％,所编码的氨基酸序列与其他物种具有较高的相似度。两种旁系同源体基因在不同组织和胚胎发育不同阶段表达水平各有所不同,其中Gp—GAPDHα在胚胎发育不同阶段的表达量存在极为显著的差异。结论在青海湖裸鲤胚胎发育研究中,Gp-GAPDHα不适合作为参照基因使用,两者的功能则需要做进一步研究。     

不同提取剂对粗细菌素提取效果的影响

摸索并建立了粗提细菌素的方法。从粗提细菌素的能力和活性保留两个方面,比较了酸沉淀法和硫酸铵沉淀法的优劣。结果发现,相对于硫酸铵沉淀法,酸沉淀法能够获得更多的粗细菌素,蛋白总量提高了28.7%。且酸沉淀法得到的粗细菌素的比活性比硫酸铵沉淀法提高了55.5%,单位效价是硫酸铵沉淀法的2倍。比较了不同有机溶剂抽提以上沉淀物,综合考虑细菌素得率及活性,发现三氯甲烷的抽提效果较好。     

鲍曼不动杆菌噬菌体生物学特性的研究

从污水中分离鉴定鲍曼不动杆菌噬菌体,并对其生物学特性进行分析,为开发针对细菌感染的噬茵体生物制剂提供前期工作.采用双层琼脂法分离可裂解鲍曼不动杆菌的噬菌体,通过负染法电镜观察噬茵体的大小和形态,将噬菌体和宿主菌以不同比例混合,测定噬菌体的最佳感染复数并观察一步生长曲线,提取噬菌体核酸进行酶切电泳分析,通过SDS-PAGE分析噬菌体的结构蛋白和非结构蛋白.成功分离3株可裂解鲍曼不动杆菌的噬菌体(分别命名为ΦAb-1、ΦAb-2和ΦAb-3),电镜显示噬菌体的头部呈二十面体,直径约50nm,有一短尾.噬菌体ΦAb-1的最佳感染复数为10-2,一步生长曲线表明噬菌体在裂解宿主菌时,潜伏期为20 min,爆发期为30 min,裂解量为190 PFU/cell.限制性酶切电泳显示噬菌体ΦAb-1的基因组大小约40 kb左右,为双股环状DNA.SDS-PAGE的噬菌体蛋白电泳包括7种蛋白,分子量在29 ～ 116 ku.噬菌体ΦAb-1、ΦAb-2和ΦAb-3对鲍曼不动杆菌具有很强的裂解毒性.根据其形态、结构和噬菌体分类法,鲍曼不动杆菌噬菌体属于有尾病毒目,足尾病毒科.     

A New Species of the Genus Protobothrops(Squamata: Viperidae) from Southern Tibet,China and Sikkim,India

A new species of the genus Protobothrops Hoge Romano-Hoge, 1983, was described from Jilong County, southern Tibet, China, and Chungthang, northern Sikkim, India. It differs from congeners by the following characters: 1) relatively large body size(total length up to 1510 mm); 2) dorsal scale rows 25–25–19; 3) except for the smooth outermost row, dorsal scales are weakly keeled; 4) relatively high number of ventral(198–216) and subcaudal(65–76 pairs) scales; 5) 7–8 supralabials; 6) 11 to 13 infralabials; 7) dorsal head uniform dark brown, laterally a reddish-brown obscure postocular streak; 8) dorsum of trunk and tail olive, with distinct black edged red brown transverse bands across the body and tail; and 9) eye from bright brown and reddish brown to mildly brown. The new species was also observed from the Haa Valley in western Bhutan.