灵芝原生质体分离与再生研究*

首次详细、系统地探讨了灵芝原生质体分离与再生的条件,结果表明：用0．6mol／L甘露醇配制成含2％溶壁酶和0．5％崩溃酶的复合酶,在30℃,pH为6.0时酶解3小时,可得到最高的原生质体得率。但考虑到原生质体的再生,以酶解2．5小时为最适。酶解2．5小时所得原生质体经精制,用纤维二糖培养基（以0.6mol／L甘露醇为渗透压稳定剂）进行双层平板（上层平板含0．2％琼脂）培养法再生,原生质体的再生率最高。本研究为以后进行灵芝原生质体的融合以及灵芝的转基因研究打下了基础。     

灵芝原生质体制备、再生及融合的研究

报道不同菌龄、酶液浓度、稳渗剂对灵芝原生质体产率及不同种类、不同浓度的稳渗剂对原生质体再生的影响。结果表明,诱变后具抗药性标记的“中国红灵芝”菌种（mH1）原生质体制备时菌丝最适菌龄为48小时,酶液浓度为3％,稳渗剂以0．6mol／L蔗糖为佳;诱变后具抗药性标记的“韩国红灵芝”（mK1）原生质体制备时菌丝最适菌龄为40小时,酶液浓度为1％,稳渗剂为0.4mol／L甘露醇时原生质体产率最高。mH1,mK1原生质体均以蔗糖作稳渗剂再生率较高,其最佳浓度为0．6mol／L。在该条件下mH1原生质体再生率为3．20×10-2,mK1为5．40×10-2。在此基础上,以30％的PEG作为融合诱导剂进行灵芝原生质体融合,并获得了融合子,融合率为140×10-2。     

灵芝原生质体分离与再生研究

首次详细,系统地探讨了灵芝原生质体分离与再生的条件,结果表明,用０．６ｍｏｌ／Ｌ甘露醇配制成含２％溶壁酶和０．５％崩溃酶的复合醇,在３０℃,ｐＨ为６．０时酶解３小时,可得到最高的原生质体得率,但考虑到原生质体的再生,以酶解２．５小时为最适。     

灵芝原生质制备,再生及融合的研究

报道不同菌龄、酶液浓度、稳渗剂对灵芝原生质体产率及不同种类、不同浓度的稳渗剂对原生质体再生的影响。结果表明,诱变后具抗药性标记的“中国红灵芝”（菌种ｍＨ１）原生质体制备时菌丝最知菌龄为４８小时,酶液浓度为３％,稳渗剂以０．６ｍｏｌ／Ｌ蔗糖为佳;诱变后具抗药性标记的“韩国红灵芝”（ｍＫ１）原生质体制备时菌丝早适菌龄为４０小时,酶液浓度为１％,稳渗剂为０．４ｍｏｌ／Ｌ甘露醇时原生质体产率最高。ｍＨｌ,     

轮梗霉原生质体的制备

本文比较了酶浓度,菌龄,渗透压稳定剂以及酶解温度和时间等因素地轮梗霉原生质体得率的影响,结果基本获得了制备原生质体的适宜条件;用0．6mol/L甘露醇稳渗剂配制成的4％纤维素酶和0．5％蜗牛酶混合酶,35℃酶解培养了30h的菌丝1．0h,即可得到较高产量的原生质体,对该生质体进行了再生实验,其再生率约为23．8％。     

康氏木霉B—7和黑曲霉X—15原生质体的形成和再生

研究了康氏木霉B－7和黑曲霉X－152株纤维素酶高产菌株的原生质体制备与再生。结果表明,采用纤维素酶、蜗牛酶、溶菌酶的混合酶液,可成功地制备2株真菌的原生质体。其中,B－7以这3种酶的配比6：5：2为最佳,X－15以8：4：2为最佳。原生质体形成的缓冲液系统均以0．2mol/L,pH6．0磷酸盐缓冲液为宜,渗透压稳定剂则分别以0．6mol/LNaCl和0．6mol/L蔗糖为宜。以菌龄18h（B-7）和16h（X－15）2株真菌的菌丝体,在37℃下酶解90min可获得最适量的原生质体,产量分别达9×106个／ml和1．9×107个／ml,且其再生率也较高,均达95％左右。     

茁芽短梗霉原生质体激光诱变及高产菌株筛选

目的：通过普鲁兰(pullulan)产生菌-茁芽短梗霉(Aureobasidium Pullulans)原生质体的激光诱变,以得到普鲁兰高产菌株。方法：利用正交实验研究了茁芽短梗霉原生质体的制备与再生并确定了其最佳条件为：菌体以1％的甘氨酸预处理;在0．1mol／L pH 6．0柠檬酸一柠檬酸钠缓冲液,含0．7mol／L NaCl的高渗稳定液中;经蜗牛酶0．2％、纤维素酶0．1％、溶菌酶0．2％的混合酶酶解15min。采用He-Ne激光诱变茁芽短梗霉原生质体筛选得到普鲁兰高产菌株J208,其蔗糖转化率达到53．3％,是原始菌株的10．6倍。结论：用激光诱变茁芽短梗霉原生质体是获得普鲁兰高产菌株的新途径。     

香菇菌丝原生质体分离与再生条件的研究

在25-26℃下培养5-6天的菌丝体,以0.8mol/L甘露醇作为渗透压稳定剂,用1.5%溶璧酶液酶解1.5-2小时,所得原生质体的产量较高,最高可达4×10⁷个/ml以上。上述条件分离的原生质体,再生率也较高。原生质体再生的温度以26℃为最佳。不同的再生培养基明显地影响原生质体的再生率。在完全培养基中加入麸皮浸出液可显著提高香菇菌丝原生质体的再生率,其中,以添加5% 麸皮浸出液的效果最好。显微观察结果表明,在液体培养集中,香菇菌丝原生质体的再生是不同步的。一般要培养20小时以后才能见到出芽,而且原生质体的再生形式也是多种所样的。     

碱性普鲁兰酶产生菌的原生质体制备与诱变选育

研究报道了Bacillus sp SX—12原生质体制备与再生最佳条件。实验表明,在液体完全培养基中加入2％的甘氨酸培养10h,原生质体制备最佳条件为：溶菌酶浓度0．5mg／mL,酶解温度37℃,酶解时间1．5h时原生质体形成率为93．8％。原生质体形成最佳高渗稳定剂为甘露醇,再生率26．4％。在原生质体制备的最佳条件下,用紫外线诱变技术选育产碱性普鲁兰酶的高产菌株。筛选到1株高产菌株SX—12C87,酶活由出发菌株的2．42μ／mL提高到6．87μ／mL,提高了约1．8倍。     

杏鲍菇原生质体制备与再生条件初探

研究酶浓度、酶解时间、酶解温度、培养时间、稳渗剂种类、pH值和几种再生培养基对杏鲍菇原生质体制备与再生的影响。最适条件为 :在 30℃、pH5 .5、1.5 %溶壁酶条件下 ,以 0 .6mol L甘露醇作为稳渗剂 ,酶解 2 .5h ,原生质体产量达到 2 .90× 10 7个 mL。将所得原生质体过滤、纯化、稀释后涂布再生培养基 ,再生率为 0 .18%。为利用原生质体技术进行杏鲍菇育种奠定了基础。     

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.