太行花性器官发育的研究——两性花中雌雄性器官发育对温度的不同要求

用太行花（Ｔａｉｈａｎｇｉａ ｒｕｐｅｓｔｒｉｓ Ｙ汃ｅｔＬｉ）试管花进行雌雄蕊发育的温度试验表明：１． 雄蕊和雌蕊的发育对温度的要求是不同的,雄蕊发育的最适温度范围偏低,接近于１～６ ℃,高于１８ ℃雄蕊全部败育。雌蕊发育的最适温度范围偏高,约６～２６ ℃,低于３ ℃,大部分雌蕊在分化早期停止发育。２． 由高温引起的雄蕊败育过程始于雄蕊原基时期,这个过程一旦启动,雄蕊败育将不会因重新将它转入低温而逆转。通过控制实验温度获得了单性雄花（１～３ ℃）、单性雌花（６～２６ ℃）和两性花（６～１２ ℃）。实验结果将为性别控制和雄性不育研究开拓新思路     

文冠果(Xanthoceras sorbifolia)研究进展

综述了文冠果（Xanthoceras sorbifolia Bunge.）的落花落果、雄性不育、遗传变异、快繁及药用等方面的研究进展。认为造成文冠果“千花一果”的生理原因可能在于树体营养不足;导致雄性不育的主要原因可能在于花药难以开裂散粉,其次才是花粉败育;文冠果花瓣等突变体的发现及体细胞胚培养成功,为优选、快繁新品种及研究木本植物的各个器官的形态建成分子机理等提供了条件,但文冠果的资源在逐年减少,有待尽快加以保护和利用;文冠果的药用价值尚有待国内深入系统地研究。     

文冠果花粉供体的多样性对果实产出的影响

很多植物的花,其柱头上接受的花粉供体多样性数量通常与果实成熟和种子产出有关。关于提高花粉多样性能否增加植物的生殖产出问题,文献中时常有相互矛盾的结论。本研究通过对自交不亲和性植物文冠果(Xanthoceras sorbifolium)进行1、2、3、4种花粉供体传粉实验,调查了不同花粉供体数量对文冠果雌性生殖的影响。结果表明,增加亲和花粉供体的多样性,一定程度上提高了花序上果实的坐果数量,同时也增加了果实中种子的数量及单粒种子重量。对文冠果授以4种亲和性花粉供体后,花序上成熟果实的平均数最多;3种亲和性花粉供体传粉后,每个果实中的种子数最多,单粒种子也最重。如果混合花粉中含有自交花粉,那么果实将败育。除花粉多样性影响雌性生殖产出外,母本基因型也具有重要影响,即增加文冠果种植品系的多样性,将有助于提高果实和种子产量。本研究还讨论了花粉遗传多样性效应、母本交配选择及果实选择性败育假说。     

文冠果性别分化关键期花芽转录组分析

为探究文冠果(Xanthoceras sorbifolium Bunge)性别分化过程的分子机制,本研究对其性别分化关键期花芽进行RNA-seq分析.结果 共获得37.13 Gb原始数据,de novo组装后共产生29430条Unigenes,平均长度1144 bp,其中21887条Unigenes获得功能注释.此外,共得到差异基因4864个,其中相对于性别分化前期(Ta)差异上调基因3003个,差异下调基因1861个.GO富集分析显示,差异基因主要注释到代谢进程、植物激素信号转导、生长素激活的信号通路等功能.KEGG富集分析显示,差异基因主要注释到植物激素信号转导、淀粉和蔗糖代谢等生物功能.还筛选出6个MADS-box相关基因(TR576|c0_g1,TR7438|c0_g1,TR10037|c1_g10,TR13325|c0_g1,TR 6316|c0_g1,TR5807|c0_ g1),参与雄蕊发育、花粉管生长、花发育调节、花瓣发育、胚珠发育、转录因子活性等过程调节.RT-qPCR检测了16个基因在两个时期的表达量,结果均与RNA-seq一致.研究结果将为进行文冠果性别分化过程中基因表达分析提供参考.     

平基槭花性别分化的细胞形态学观察

平基槭为杂性花,雄花与两性花同株,本文对其花性别分化过程进行了细胞形态学观察。结果发现,在花性别分化的早期,雄花和两性花的花芽中雌、雄蕊原基均具备,只是在花芽发育到一定时期,雄花的雌蕊原基发生选择性败育,败育发生在大孢子母细胞减数分裂为4个大孢子时期。两性花的雌蕊可以正常膨大结实,雄蕊花药虽然可以形成二核花粉,但不能正常开裂,属于不育雄蕊。初步分析认为,两性花雄蕊花药不能正常开裂与花粉囊壁纤维层木质化程度低有关。     

中国北亚热带油橄榄(城固32)开花生物学特性研究

为研究北亚热带内陆地区油橄榄（Olea europaea L.）开花物候、开花样式及花器官特征,探讨其有性繁殖系统的特点。试验对西秦岭南坡地区油橄榄（城固32）的开花生物学进行研究,统计开花进程,雄花和两性花在花序上的着生位置和数量,测定雄花和两性花形态指标并切片观察,电镜扫描分析雄花与两性花花粉粒。结果表明：（1）在北亚热带北缘内陆气候条件下油橄榄花期集中在5月,单株花期15~20 d,盛花期持续4~6 d;（2）油橄榄具有雄全同株的性系统且花器官较小,雄花及两性花都具有正常发育的雄蕊。通过制作石蜡切片观察,发现两性花的雌蕊正常发育,而雄花只有较小的子房和败育的柱头;（3）雌蕊是两种花型花器官生物量差异的主要部位,两性花雌蕊的生物量明显比雄花大（P<0.01）,树体分化出雄花投入的资源更少;（4）雄花与两性花在花粉量、花粉粒大小上差异不显著,在着生位置上,花序轴顶花全部为两性花,雄花出现在花序轴的中部和基部的几率分别是21.13%和30.77%。油橄榄品种城固32具有典型的雄全同株现象,雄花更倾向于在花序上出现的位置在行使它雄性功能方面并无优势可言,而且雄花花粉粒在数量、活力方面也没有优势,但是雄花的出现增加了花粉数量和P/O值,提高了植株的雄性适合度,雄花的出现也降低了两性花落花导致的树体资源浪费,保障其在资源有限的环境中能够繁殖最大化。     

拟南芥RUS4基因沉默对花药药室内壁次生加厚的影响

RUS4是拟南芥DUF647蛋白家族的一个功能未知的成员。沉默RUS4基因引起植株育性严重下降,但育性下降的具体机制尚不清楚。该研究通过观察RUS4基因沉默突变体(称为RUSamiRNA)不同时期花的发育情况,发现其雌蕊发育正常,雄蕊花丝伸长正常,主要缺陷是花药不能正常开裂;通过对RUS4-amiRNA植株花药发育的细胞形态学观察,发现其药室内壁缺乏次生加厚;qRT-PCR分析表明, RUS4-amiRNA花蕾中与植物次生壁加厚相关的转录因子基因NST1、NST2、MYB103和MYB85以及纤维素合成基因IRX1、IRX3、IRX5和IRX8的表达均大幅降低。该研究表明,RUS4可能通过影响次生壁形成相关基因的表达参与花药药室内壁次生壁的形成。     

醮核荔枝胚胎发育相关蛋白质的分离及初步鉴定

通过二维聚丙烯酰胺凝胶电泳以及计算机辅助的图像分析技术,对荔枝开花后40d的正常与败育胚蛋白质图谱进行初步分析。结果表明,100个蛋白质点在表达丰度上有明显差异;选择仅在正常发育胚胎胶上表达的蛋白点15个和仅在败育胚胎胶上表达的蛋白点50个,进行基质辅助激光解吸附电离飞行时间质谱（MALDI—TOFMASS）分析,鉴定出9个与胚发育相关的蛋白,这些蛋白可能参与了胚败育的调节和控制。     

Cct6a对鸡卵泡膜细胞Bcl-2和Caspase-3表达的影响

Cct6a基因编码CCT（chaperonin containing tailless complex polypeptide）的ζ亚基,属Ⅱ型伴侣素,是一种广泛存在于细胞浆中的异型寡聚蛋白,在肌动蛋白、微管蛋白的组装和折叠中发挥着重要的作用. Cct6a在鸡性成熟和卵泡发育中发挥重要作用,然而其在卵泡发育中的分子机制尚不十分清楚. 本研究采用qRT-PCR分析了Cct6a在鸡卵泡细胞中的表达,结果表明,Cct6a在鸡卵泡膜细胞中高表达,并与卵泡体积的增大相关. 利用shRNA对鸡卵泡膜细胞中的Cct6a基因进行了敲低分析,转染48 h后鸡卵泡膜细胞中Bcl-2基因的表达量显著降低（P=0.0429）,Caspase-3基因的表达无变化;过表达Cct6a后的鸡卵泡膜细胞中Bcl-2基因的mRNA表达量有增高趋势,Caspase-3基因的mRNA表达量呈下调趋势. 因此,在鸡卵泡膜细胞中Cct6a影响Bcl-2基因表达,是否Cct6a可影响Caspase-3基因表达尚需进一步实验证明.     

荔枝雌蕊发育过程中钙分布变化与细胞程序性死亡

应用焦锑酸钾沉淀法研究了荔枝雌花和雄花雌蕊发育过程中钙的分布变化。在大孢子母细胞阶段,雌花近珠孔内珠被细胞和花柱细胞的钙沉淀颗粒主要分布在细胞壁和细胞间隙,少部分在液泡;雌花花柱维管细胞中含有很多的钙沉淀颗粒;在雄花的近珠孔内珠被细胞钙沉淀颗粒大多在液泡中;雄花花柱细胞和维管细胞中钙沉淀颗粒很少。大孢子母细胞减数分裂后,雌花雌蕊继续发育,雄花雌蕊败育。雌花维管中的钙沉淀颗粒数量减少,可能被转运到将要发生花粉萌发和受精的部位。雌花近珠孔内珠被细胞壁的钙沉淀颗粒分布增加,花柱细胞从上（近柱头）到下（近子房）钙沉淀颗粒量递增。雄花近珠孔内珠被细胞发生程序性死亡：液泡中的钙进入细胞核启动细胞程序性死亡,核周隙与质膜腔形成连续的通道,钙在核与细胞质之间的流动不受限制;在特定的时间段,钙沉淀颗粒出现在线粒体、过氧化物体和线型内质网的外膜上。钙在细胞中重新分布可能触发和调节细胞程序性死亡的进程。缺乏钙沉淀颗粒的雄花花柱细胞迅速解体。     

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.