不同因素对金针菇原生质体制备和再生的影响

比较了不同浓度裂解酶及组合、渗透压稳定剂、酶解时间等因素对金针菇原生质体得率的影响以及不同渗透压稳定剂、培养基、接种方法等因素对金针菇原生质体再生的影响。试验结果表明:固体培养10d的金针菇菌丝,以0.5mol/L KCl作渗透压稳定剂,加入1%纤维素酶和1%溶菌酶在25℃下酶解1.5h,分离原生质体效果最佳,原生质体产量可达27.8×105个/ml以上;以0.5mol/L KCl作渗透压稳定剂,在25℃条件下,金针菇原生质体采用直接涂布法接种在RCM培养基上培养,再生率最高为0.5%。     

姬松茸原生质体形成和再生的研究

报道了溶壁酶系统、酶浓度、不同菌龄、脱壁促进剂、渗透压稳定剂和酶解温度对姬松茸原生质体释放率及不同再生培养基、渗稳剂种类、菌丝酶解时间和单双层平板对原生质体再生的影响。结果表明 ,菌龄为3～ 5d的菌丝以 1.5 %溶壁酶、0 .5 %蜗牛酶和 0 .5 %纤维素酶组成的酶系统在 30℃以KCl为渗透压稳定剂时 ,形成率为 1.4～ 1.5ⅹ 10 7/mL酶液 ;以蔗糖为渗透压稳定剂 ,菌丝酶解 1.5～ 3h ,以SMY和MYP为再生培养基 ,姬松茸原生质体再生率为 1.1‰～ 1.3‰。     

丝状真菌AL18的原生质体制备和再生条件的优化

目的:为了建立起产苝醌类光敏剂丝状真菌AL18原生质体制备和再生体系。方法:采用单因素实验法研究了预处理方式、渗透压稳定剂和酶解条件对原生质体制备率和再生率的影响。结果:原生质体制备及再生的最佳条件是用0.3%的β-巯基乙醇预处理15 min,酶解液以0.6 mol/L的MgSO4·7H2O作为渗透压稳定剂,0.02 mol/L的磷酸盐缓冲液pH值为5.8,纤维素酶:蜗牛酶=2:3,酶的总浓度为15mg/mL,36℃酶解2h;以0.6mol/L的蔗糖作为再生培养基的渗透压稳定剂。结论:原生质体的制备率和再生率可分别达到1.42×107/mL和3.2%。     

大丽轮枝菌原生质体的制备及再生

为建立大丽轮枝菌(Verticillium dahliae)原生质体的制备和再生体系,采用单因素分析法分析了大丽轮枝菌摇培时间、裂解酶浓度、酶解时间和温度、渗透压稳定剂的种类和浓度及pH对原生质体释放的影响;从再生培养基、培养基Agar浓度和酶解时间对原生质体的再生条件进行了优化;并对优化条件下获得的原生质体进行了GFP瞬时表达。结果表明,将分生孢子培养18 h收集菌丝体,以1.2 mol/L的KCl作为渗透压稳定剂,在pH 6.0的条件下,加入10 mg/m L的裂解酶,30℃酶解4 h时,获得的原生质体产量最高,达到3.3×10~7个/mL;在Agar浓度为0.5%的TB3再生培养基中进行原生质体再生,再生率最高,可达22.45%;GFP瞬时表达结果表明,优化条件下获得的原生质体可用于遗传转化材料。     

赤芝原生质体分离与再生研究

以赤芝(Ganoderma lucidum)为供试菌种,研究了不同酶解温度、酶解时间、渗透压稳定剂浓度及菌龄、再生培养基等对赤芝菌丝的原生质体制备与再生的影响。结果表明:菌龄为4 d的菌丝,以0.4 mol/m L的甘露醇作渗透压稳定剂配制成浓度为0.02 g/m L的溶壁酶,于p H 5.0、25℃条件下酶解2.0 h,其原生质体数最高可达3.87×107/m L,MYG再生培养基上再生率达到0.016%。     

平菇原生质体制备与再生条件初探

平菇原生质体制备最佳条件是菌丝培养5 d、酶浓度1.5%、pH 5.5、0.6 mol/L甘露醇渗透压稳定剂、酶解温度30℃、酶解时间2 h、OS培养基。原生质体过滤、纯化、稀释后涂布再生培养基,再生率为2.6%。     

木质层孔菌原生质体的制备与再生条件的研究

目的：提高木质层孔菌原生质体的产量和再生率,为进一步诱变育种提高菌株产木质纤维素酶活力打下基础。方法：通过单因素实验分别筛选合适的酶浓度、菌丝的菌龄、酶解温度、酶解时间、渗透压稳定剂与pH值。结果：在酶解液浓度为2.0%纤维素酶＋2.0%蜗牛酶、菌龄60h、酶解温度32℃、酶解时间3h,以0.8mol/L的NaCl溶液为渗透压稳定剂,pH值为5.0时,原生质体形成量达4.13×10^5个/mL,再生率可达6.95%。有效地提高了木质层孔菌原生质体的产量和再生率。     

假丝酵母原生质体形成与再生的研究

本文研究了菌龄、酶系统、脱壁促进剂、渗透压稳定剂对假丝酵母Y002 原生质体形成与再生的影响。综合考虑形成率与再生率后,选用对数生长中期的菌体于1%蜗牛酶、 35℃下作用60分钟制备原生质体,并于以17%蔗糖作渗透压稳定剂的再生培养基中再生效果为好。     

斜卧青霉原生质体制备和再生的研究

研究了斜卧青霉原生质体制备和再生的条件,确定了培养方式、菌龄、渗透压稳定剂、酶的配比、酶解时间等因素对原生质体制备和再生的影响。最佳条件：菌丝体培养12h,用1％溶壁酶＋1％纤维素酶＋1％蜗牛酶的混合酶液酶解,将NaCl作为渗透压稳定剂,酶解时间为1．5h。在此条件下原生质体的形成量达到5．3×10^5个／mL,再生率为19．4％。     

小花棘豆Embellisia内生真菌原生质体的制备与再生研究

旨在获得数目多且活力高的小花棘豆Embellisia内生真菌的原生质体,分析和探讨该内生真菌原生质体制备与再生的最佳条件,为后续外源基因转化奠定基础。利用酶解法对制备小花棘豆Embellisia内生真菌菌丝的原生质体,研究酶解液成分、p H、温度、渗透压稳定剂、酶解时间及菌龄对原生质体制备和再生的影响;原生质体在TB3培养基上再生后,研究酶解时间对原生质体再生的影响。结果显示,2.5%(W/V)lysing enzymes、2%(W/V)纤维素酶和3%(W/V)蜗牛酶3种混合酶处理,菌龄为10 d,当酶解温度为30℃、p H5.8、1.2 mol/L Mg SO4为渗透压稳定剂,在80 r/min水平摇床酶解8 h时,原生质体浓度较高,达4.42×105个/m L;酶解时间6 h时再生率最高,达46.7%。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.