青菜与芥菜花粉－体细胞原生质体融合的研究

以聚乙二醇（ＰＥＧ）为诱导剂,试验用４种方法进行青菜（Ｂｒａｓｓｉｃａｃｈｉｎｅｎｓｉｓ）幼嫩花粉原生质体与芥菜（Ｂ．Ｊｕｎｃｅａ）下胚轴原生质体的融合,结果以修改的Ｔｅｒａｄａ等的方法最好。融合后原生质体的培养形成了愈伤组织,但未分化出芽,个别愈伤组织分化了根。用ＲＡＰＤ技术对任选的５个细胞系进行鉴定,发现１个细胞系含双亲的ＤＮＡ片段,可确认是青菜幼嫩花粉原生质体与芥菜下胚轴原生质体融合后产生的杂种细胞系。     

芸苔属花粉—下胚轴原生质体融合再生杂种小植株

从青菜（Ｂｒａｓｓｉｃａ ｃｈｉｎｅｎｓｉｓＬ．）单胞中后期至二胞早期花粉分离出原生质体,用聚乙二醇法诱导其与甘蓝型油菜（Ｂ．ｎａｐｕｓＬ．）下胚轴原生质体融合。通过控制双亲原生质体的数量与比率,提高了异源融合率。融合体在离体条件下发生细胞分裂,形成愈伤组织,再生了小植株。染色体计数与酯酶同工酶酶谱分析初步证明获得了１ 株异源三倍体,２ 株异源四倍体。这是以游离花粉时期的原生质体与体细胞原生质体融合,取得“配子－体细胞杂交”成功的首次报道     

烟草花粉原生质体与叶肉原生质体的融合及培养早期变化

用ＰＥＧ—高Ｃａ高ＰＨ法诱导抗卡那霉素的烟草（Ｎｉｃｏｔｉａｎａｔａｂａｃｕｍ）品系Ｎ３６４＋Ｋｍ＋花粉原生质体和黄花烟草（Ｎｉｃｏｔｉａｒｕｓｔｉｃａ）叶肉原生质体融合。幼嫩花粉原生质体和叶肉原生质体之间的融合体培养启动胚胎发生分裂,经卡那霉素筛选后,少数多细胞团存活并形成小愈伤组织。成熟花粉原生质体与叶肉原生质体之间的融合体则仅产生管状结构。这一结果表明,作为融合一方的花粉原生质体的发育时期对融合产物的发育途径有重要影响。     

甘蔗原生质体的体细胞胚胎发生

用甘蔗(台糖134)花粉植株叶外植体产生的愈伤组织,作为分离原生质体的材料。原生质体以液体浅层培养的方式培养在修改的 MS 培养基上,经培养后一周内,观察到第一次细胞分裂,约5—6周后,形成了愈伤组织。将胚性细胞团组成的愈伤组织转移到除去或降低2,4-D浓度,但含有 BA 的分化培养基上,约2—3周后,有的愈伤组织发育了胚芽鞘,另一些愈伤组织分化出胚根或根。系统观察了这些原生质体在分裂和愈伤组织形成过程中的体细胞胚胎发生。     

提高小麦原生质体再生植株频率的研究

从小麦徐州211的成熟种子诱导愈伤组织,建立了胚性悬浮细胞系。酶解悬浮细胞获得原生质体,用含o．8％琼脂糖的改良Ms培葬基进行琼脂糖珠培养,再生细胞分裂,并形成愈伤组织。诱导再生愈伤组织分化．得到了完整的再生植株。原生质体培养两周后,加入降渗培养液可促进克隆的形成。在分化培养基中,低浓度蔗糖可提高植株分化率。高浓度的激动索和玉米素对芽的分化有效并能抑制愈伤化。再生愈伤组织诱导分化时期的早晚影响植林分化频率。     

沙打旺原生质体培养再生植株

用1%半纤维素酶,0.4%纤维素酶,0.1%果胶离析酶,CPW9M酶液分离沙打旺无菌苗下胚轴和子叶原生质体。K8P原生质体培养基悬滴培养。下胚轴原生质体形成小细胞团后用琼脂糖包埋培养,形成小块愈伤组织后转入增殖培养基M1、M2(改良MS培养基)上形成大块愈伤组织。经过两次诱导分化,在分化培养基M3(MS 0.7mg/L BA 0.2mg/L NAA),M4(MS 0.5mg/L BA 0.5mg/L KT 0.5mg/L ZT 0.2mg/L NAA)和M6(MS 3mg/L ZT 0.2mg/L IAA)上分化出苗,再生植株。由子叶分离的原生质体未能形成愈伤组织。     

多变小冠花(豆科牧草)原生质体和外植体胚状体的形成和植株的再生

EM-5游离大量的多变小冠花实生苗子叶原生质体。Kao的原生质体培养基使子叶原生质体分裂形成细胞团。MSD_4诱导多变小冠花原生质体愈伤组织产生胚状体、苗和植株的分化。MS-1诱导多变小冠花实生苗根、下胚轴和子叶愈伤组织的形成,胚状体、苗和值株的分化。根愈伤组织胚状体形成的频率(60%)高于子叶和下胚轴的(<23%)。组织切片的观察表明多变小冠花原生质体植株的再生通过胚状体形成的途径。     

小麦与燕麦不对称体细胞杂交的研究

以小麦品种济南177的悬浮细胞系(长期继代培养已丧失分化能力)来源的原生质体混合同品种胚性愈伤组织(分化能力较强, 约70%)制备的原生质体为受体, 以经300 mW/cm²紫外线照射0.5, 1, 2, 3, 5 min的普通燕麦愈伤组织(分化频率很低, 约10%)原生质体作供体, 用PEG法诱导融合. 可高频率地获得体细胞杂种细胞系, 并分化获得绿色正常的再生植株, 经荧光原位杂交、 同工酶及5S rDNA间隔序列分析, 确认了它们为体细胞杂种. 单独使用小麦胚性悬浮系或愈伤组织为受体获得的杂种克隆均未能得到绿色植株.     

普通小麦与无芒雀麦不对称体细胞杂交的研究

普通小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）９９Ｐ原生质体与经紫外线照射的无芒雀麦（ＢｒｏｍｕｓｉｎｅｒｍｉｓＬｅｙｓ）愈伤组织来源的原生质体用ＰＥＧ法诱导融合。融合再生的３个单细胞克隆（Ｎｏ．１～Ｎｏ．３）经染色体、同工酶和ＲＡＰＤ分析表明,它们均为杂种细胞系。Ｎｏ．１克隆形成的愈伤组织分化出大量白化苗,其叶片同工酶和ＲＡＰＤ分析均出现双亲特征谱带及新带,白化苗的染色体数目为４２～５４,大于亲本小麦,并具有无芒雀麦的小染色体和染色体断片,确认它们为不对称体细胞杂种。     

湖北海棠原生质体培养获得愈伤组织(简报)

由湖北海棠成熟胚下胚轴诱导愈伤组织并建立悬浮细胞系,用0．5％纤维素酶R－10和0．2％果胶酶分离悬浮系细胞,将酶解的原生质体培养在附加激素和有机成分的MT培养基中,采用液体浅层培养,获得了愈伤组织。     

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.