水稻颖花开裂基因srs-1定位及其同源异型功能分析

以水稻颖花突变体SRS (split rice spikelet)为父本, 窄叶青8号为母本配制杂交组合, 根据其F2代表型及X2测验结果, 表明突变性状是由单隐性基因srs-1决定的. 采用BSA法, 利用RAPD技术在正常池和突变池间寻找多态性标记, 通过筛选520个10碱基引物, 得到了6个能在两池间扩增出多态性条带的引物, 其中最好的是S465, 并成功地将此标记转化为RFLP标记, 该标记在F2群体上表现共分离. 在DH群体上进行基因定位, 将该基因定位在第3染色体上. 该基因的突变导致水稻两稃片变软、变长, 内外稃不抱合, 两稃交接处分别有一质地与稃片类似的小片状物, 雄蕊9枚, 雌蕊2枚. 推测该基因属于同源异型A组基因.     

一个新的水稻花器官突变体的鉴定和基因定位

在水稻（Oryza sativa）品种台中65的组培后代中发现一个花器官发育异常突变体flower organ number6（fon6）,其主要表型为：双子房,多柱头,7-8枚雄蕊。遗传分析表明,该突变表型由一对隐性基因控制。以该突变体与籼稻3037杂交的F2代分离群体作为定位群体,利用STS标记将与突变性状相关的基因定位于第6染色体短臂上STS标记PL4和PL5之间约480kb的范围内。该研究结果为进一步的基因克隆及功能研究奠定了基础。     

水稻叶状颖壳突变体Oslh的遗传分析和OsLH基因的定位

通过γ射线诱变,从粳稻品种9522的M2代中筛选出一株具有叶状颖壳的突变体,定名Oslh(1h=leafy hull).Oslh突变体的开花时间要比野生型晚15 d左右,内外稃和浆片发育成了叶片状器官.Oslh突变体与粳稻品种9522回交结果表明Oslh突变性状可能由单核基因隐性突变造成.以Oslh突变体与籼稻品种广陆矮4号杂交的F2代群体为基因定位群体,利用SSR和InDel分子标记将Oslh突变位点定位在3号染色体上的SSR标记RM5475和InDel标记GY305之间,遗传距离分别为2.5 cM和1.9 cM.这些结果为克隆OsLH基因和研究花器官发育的调控机理奠定了基础.     

小麦穗部发育多效基因的遗传分析与基因定位

在小麦育种材料中首次发现一种穗部发育萎缩且花器官明显退化,但茎、叶等其他器官发育正常的突变体sda1(spike development atrophy 1)。用显微镜观察突变体sda1的花器官,用碘-碘化钾鉴定其小孢子育性;以‘陕麦94’为父本,突变材料sda1为母本构建F2群体,调查各主要农艺性状,灌浆期测定穗部及穗下茎可溶性糖含量、旗叶光合性能(净光合速率、气孔导度、胞间CO2浓度、蒸腾速率),对该突变体进行遗传分析;利用SSR微卫星标记,通过混合分离分析(BSA)和群体连锁分析进行基因定位,进一步探索该基因功能。结果表明:(1)小麦突变体sda1雄蕊发育畸形,雌蕊发育萎缩,小孢子几乎全部丧失育性。(2)对突变体sda1原株系中表型正常植株的后代分离统计分析结果证明,该突变性状由1对隐性核基因控制,并命名该基因为SDA1。(3)在F2群体中,突变株抽穗期较正常株延迟4d;穗部及穗下茎可溶性糖含量分别显著高于正常株30.6%和11.0%,但突变株与正常株的抽穗持续时间(均为8d)和光合性能无显著差异。(4)经基因定位分析初步确定SDA1位于小麦6B染色体WMC398和BARC136标记之间,与两标记的遗传距离分别为2.2cM和2.1cM。推测认为,SDA1是一个控制抽穗期与器官发育的多效基因,且该基因突变影响植株的糖分转化与利用。     

一个新的水稻叶绿素缺失黄叶突变体的特征及基因分子定位

从粳稻"嘉花1号"60Coγ射线辐照的后代中筛选到一个叶绿素缺失黄叶突变体(yl11),与野生型"嘉花1号"相比该突变体表现为全生育期植株叶片呈黄色,叶绿素含量以及净光合速率明显下降,叶绿体发育不完善,并且伴随着株高等主要农艺性状的变化。遗传分析表明,该突变性状受一对隐性核基因(yl11)控制。该突变体与籼稻"培矮64S"杂交生产的F2、F3群体中的分离出突变体型920个单株作为定位群体,利用SSR和InDel分子标记将yl11基因定位在水稻第11染色体长臂上的MM2199和ID21039分子标记之间,其物理距离约为110kb,目前该区域内没有发现与水稻叶绿素合成/叶绿体发育相关已知功能基因。研究结果为今后对该基因的克隆和功能分析奠定了基础。     

一个显性卷叶突变体z2的遗传分析与精细定位

叶片的适度卷曲对水稻理想株型育种具有重要意义。在水稻T-DNA插入突变体库中获得一个叶片外卷突变体z2,突变体表型出现在分蘖期;与野生型相比,农艺性状无明显差异,光合作用效率高于野生型。对突变体和野生型的石蜡切片研究表明,突变体叶片泡状细胞数量(8-9个)明显多于野生型(4-5个)。z2卷叶性状遗传稳定,由一对显性核基因控制。以z2纯合突变体为母本,籼稻Dular为父本进行杂交构建F2代定位群体,利用图位克隆的方法,将该基因初定位于水稻第2号染色体的In Del1812与In Del1870标记之间,物理距离为580 kb。     

水稻白色中脉Oswm2的遗传分析与分子标记定位

从T-DNA突变体库中获得一份以中花11为遗传背景的白色中脉突变体。该突变体剑叶以下叶片的中下部中脉表现为白色, 白色中脉附近的叶色微黄, 并且伴随株高等农艺性状的改变, 暂时将其定名为Oswm2(Oryza sativa white midrib 2)。遗传分析表明该突变性状受一对隐性单基因控制, 以Oswm2和粳稻02428杂交的F2分离群体作为定位群体, 将OsWM2基因定位在水稻第7染色体的SSR标记RM21478和RM418之间, 遗传距离分别为8.7和15.9 cM。     

水稻颖花开裂SRS突变体的鉴定

利用扫描电镜观察了水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）颖花开裂突变体ＳＲＳ（ｓｐｌｉｔ ｒｉｃｅ ｓｐｉｋｅｌｅｔ）花器官形态发生过程,该突变体表现为内外稃变软变长,不抱合,外稃基部又着生一颖花,浆片呈稃片状,但是雌雄蕊着生位置和形态表现正常。利用ＳＲＳ突变体为父本,“窄叶青８号”为母本配制杂交组合,其Ｆ２代群体中正常与突变植株的分离比例为３：１,表明该突变性状是由单隐性基因控制的。作为对照,同     

烟草黄绿叶突变体的遗传分析与基因定位

以G117为父本、RG13为母本,杂交获得F1群体。系谱法常规选择过程中,在F3株系内发现黄绿自然隐性突变株。该突变体的叶色在旺长期前呈现正常绿色,进入旺长期后,叶色逐渐发黄,叶脉呈乳白色,与正常烟株差别明显。遗传分析表明该突变体性状受1对隐性基因控制。从来源于一个连续自交单株的分离群体中分别选取10份隐性纯合烟株和10份显性烟株,利用430K烟草高密度SNP芯片进行基因型分析,快速确定了与目标性状相关联的标记。进而利用该分离群体验证相关分子标记,将该基因定位在烟草第5号染色体M7和M18之间,并与M7标记共分离。相关研究为进一步克隆该基因奠定了基础,同时也为烟草其他重要性状的定位提供了一种有效、快速的方法。     

一个新的水稻卷叶突变体的遗传分析与基因定位

水稻叶片发育异常的突变体是研究水稻叶片发育分子机理的重要材料．本研究在IR64的EMS突变体库中发现了一个新的卷叶突变体材料w32,在整个生育期过程叶片都表现高度卷曲．突变体w32与IR24、培矮64杂交构建F2群体进行遗传分析,结果表明,卷叶性状受一个隐性基因控制,选用w32/PA64F2群体中的1846个卷叶单株进行基因定位,在卷叶和正常叶的DNA池中筛选到两个多态性标记RM6697和RM20781,并确定该卷叶基因位于第7染色体短臂上,是一个尚未报道过的基因,暂命名为r111（t）．利用新发展的11个SSR标记和19个InDel标记,最终将r111（t）基因定位在一个约52kb的区段上,为最终克隆该卷叶基因奠定了基础。     

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.