小麦春化相关基因的克隆及其功能分析

一． 小麦相关基因ver203F cDNA全序列克隆与功能分析 　　根据本实验室通过差异筛选技术克隆到的与春化相关的基因cDNA verc203的序列，设计PCR 5’端PCR引物，利用RACE（rapid amplification of cDNA ends）克隆策略，得到春化相关基因ver203基因的同源基因ver203F cDNA的3’端序列，长度为1,197bp。Northern分析表明ver203F全长约为1.5 kb，且其表达具有春化处理的特异性。根据3’RACE克隆的ver203F 3 ’端核苷酸序列设计了3’端PCR引物，利用5’RACE克隆到该基因的5’端片段，经DNASIS核酸分析软件分析将5’45RACE和3’RACE DNA序列拼接合并，得到ver203F全长cDNA，从TdT加尾5’末端到poly A全长为1,561 bp，5’端起始密码子ATG上游非编码区－1～－192共了192bp，终止密码子TGA到poly A的非编码区有253bp，cDNA编码区全长1,119 bp，推测编码373氨基酸残基。国际基因序列数据库检索表明该基因序列（GenBank/EMBL/DDBJ：AB012013）与大麦茉莉酸诱导基因有部分同源性。因上推测该基因在调控开花过程中可能参与茉莉酸介导的信号传导途径，ver203F作用的发挥可能需要其它蛋白的参与，或ver203F本身就是一个受体蛋白。 　　为了研究ver203F基因的功能，将通过3’RACE克隆到的ver203F 3’端序到分别构建正义和反义植物表达载体，通过花粉管通道法、农杆菌介导的叶圆片法以及农杆菌介导的真空转化法分别转化小麦、烟草和拟南芥菜。获得转基因植株后，PCR、DNA Dob Blot、Southern Blot分析以及GUS活性检测证明外源基因已整合到转基因植株中，并得到表达。在获得的小麦、烟草和拟南芥菜转基因植株中，它们开花时间都相应地推迟，表明正常植物体内该基因在控制营养生长向生殖生长的转变中起作用。ver203F可以影响小麦和拟南茶菜花序的发育，首先无论正义还是反义都使得花序的发育受到抑制，在小麦中表现为顶部小穗退化，在拟南芥菜中表现为顶花。其次在转化正义基因的转基因拟南芥菜中，观察到产生的顶花为对称的两朵或以对称的两朵顶花基部为生长点长出丛生花，这种对称花的麦型小麦小穗中小花的表型相类似，说明ver203F基因可能在小麦小花的发育过程中也起着重要作用。 二． 春化相关基因ver17在开花过程中功能的分析 以春化处理冬小麦（京冬1号）幼苗cDNA为材料，通过减法杂交与差异筛选得到春化相关cDNA克隆verc17。为了研究该基因的功能，以包含CaMV 35S启动子的pBI221为载体，将ver17cDNA片段分别从两个方向插入pBI221的BamH I－Sma I, Xba I－BamH I间，构建正义和反义表达质粒：p17S和p17X，通过花粉管通道法转化小麦。对T0和T1两代转基因小麦的观察发现，在转化反义基因p17X的转基因小麦首先表现为抽穗推迟，其次穗的顶部和基部小穗严重退化，另外还发现转化反义基因的小麦败育现象严重（主要是花粉败育），因此推测ver17基困能可具有以下几方面的特点：a．春化诱导型表达;b．促进植物开花;c．促进穗顶端和基部花的发育，减少其退化;d．影响雄蕊的发育。

THE CHROMOSOMES OF TUFTED DEER (ELAPHODUS-CEPHALOPHUS)

Mitotic and meiotic chromosome preparations of the tufted deer (Elaphodus cephalophus) were studied to elucidate the sex-chromosomal polymorphism evidenced by this species. Females had 2n = 46 or 47 chromosomes, whereas males had 2n = 47 or 48 chromosomes. An X;autosome translocation was identified by synaptonemal complex analysis of spermatocytes at pachytene and confirmed by the presence of a trivalent at diakinesis/metaphase I. The present work, in combination with earlier observations by others, indicates that E. cephalophus possesses a varied X-chromosome morphology involving an X;autosome translocation and addition of varying amounts of heterochromatin. It is speculated that sex-chromosome polymorphism may be responsible for the observed differences in diploid chromosome number of tufted deer.

乳腺增生病p53基因第6外显子突变检测

目的 :探讨p5 3基因在乳腺癌发生早期的作用及早期诊断乳腺癌的分子病理指标。方法 :用PCR -SSCP检测36例乳腺单纯性增生、 31例不典型增生、 30例乳腺癌中p5 3基因第 6外显子突变 ,用DNA直接测序技术确定突变的碱基及其所在的密码子。结果 :乳腺单纯性增生、不典型增生、乳腺癌中p5 3基因第 6外显子的突变率分别为 0、6 5 % (2 / 31)、 13 3% (4/ 30 )。 6个点突变均为碱基替换 ,其中 4个发生于第 192密码子 (CAG→TAG) ,2个发生于第2 13密码子 (CGA→TGA) ,两者均导致多肽链合成提前终止。结论 :乳腺癌不典型增生中存在p5 3基因第 6外显子突变 ,该突变可能在乳腺不典型增生发展到乳腺癌过程中起重要作用 ,可作为早期诊断乳腺癌的辅助指标。

我国北方部分山羊品种mtDNA遗传多样性

我国北方地区有丰富的山羊品种遗传资源。这些遗传资源是人类赖以生存的宝贵基因库之一，是山羊育种不可缺少的重要的遗传材料。因此，对其遗传多样性进行研究具有十分重要的理论和实践意义。然而目前对这些山羊品种的遗传差异，特别是分子遗传的差异却知之甚少。本试验对中国北方地区部分山羊品种和类群的线粒体DNA的限制片段长度多态性进行了研究，以期为我国北方地区山羊品种的起源及遗传分化研究、群体的遗传结构和亲缘关系研究以及品种遗传资源的合理利用和保护研究提供基础资料和科学依据。

Molecular evolution of growth hormone gene family in old world monkeys and hominoids

Growth hormone is a classic molecule in the study of the molecular clock hypothesis as it exhibits a relatively constant rate of evolution in most mammalian orders except primates and artiodactyls, where dramatically enhanced rate of evolution (25-50-fold) has been reported. The rapid evolution of primate growth hormone occurred after the divergence of tarsiers and simians, but before the separation of old world monkeys (OWM) from new world monkeys (NWM). Interestingly, this event of rapid sequence evolution coincided with multiple duplications of the growth hormone gene, suggesting gene duplication as a possible cause of the accelerated sequence evolution. Here we determined 21 different GH-like sequences from four species of OWM and hominoids. Combining with published sequences from OWM and hominoids, our analysis demonstrates that multiple gene duplications and several gene conversion events both occurred in the evolutionary history of this gene family in OWM/hominoids. The episode of recent duplications of CSH-like genes in gibbon is accompanied with rapid sequence evolution likely resulting from relaxation of purifying selection. GHN genes in both hominoids and OWM are under strong purifying selection. In contrast, CSH genes in both lineages are probably not. GHV genes in OWM and hominoids evolved at different evolutionary rates and underwent different selective constraints. Our results disclosed the complex history of the primate growth hormone gene family and raised intriguing questions on the consequences of these evolutionary events. © 2005 Elsevier B.V. All rights reserved.

A STUDY ON THE EFFECT OF LESIONS OF AREA-7 OF THE PARIETAL CORTEX ON THE SHORT-TERM VISUAL SPATIAL MEMORY OF RHESUS-MONKEYS (MACACA-MULATTA)

This research is focused on the contribution of area 7 to the short-term visual spatial memory. Three rhesus monkeys (Macaca mulatta) were trained in the direct delayed response task in which 5 delay intervals were used in each session. When each monkey reached the criterion of 90% correct responses in 5 successive sessions, two monkeys underwent a surgery while the other one received a sham operation as a control. In the first stage of the surgery, bilateral areas 7a, 7b and 7ip of the parietal cortex of two monkeys were precisely lesioned. After 7 days of recuperation, the monkeys were required to do the same task. The average percentage of correct responses in the lesioned animals decreased from 94.7% to 89.3% and 93.3% to 82.0% respectively (no significance, P > 0.05, n = 2). In addition, the monkeys' complex movements were mildly impaired. The lesioned monkeys were found to have difficulty picking up food from the wells. In the second stage, bilateral area 7m was lesioned. In the 5 postoperative sessions, the average percentage of correct responses in one monkey, with a relatively precise 7m lesion, decreased from 94.7% to 92.2% (no significance, P > 0.05), while the other monkey, with widely spread necrosis of lateral parietal cortex, showed an. obvious decline in performance, but still over the chance level. After 240 trials this monkey reattained the normal criterion. The results of this research suggest that the lesions of area 7 of the parietal cortex did not significantly affect the short-term visual spatial memory, which has been shown to be sensitive to lesions of the prefrontal cortex; they also support the notion of dissociation of spatial functions in the prefrontal and parietal cortices.

The effect of acute stress on LTP and LTD induction in the hippocampal CA1 region of anesthetized rats at three different ages

Not all experiences are memorized equally well. Especially, some types of stress are unavoidable in daily life and the stress experience can be memorized for life. Previous evidence has showed that synaptic plasticity, such as long-term potentiation (LTP) that may be the major cellular model of the mechanism underlying learning and memory, is influenced by behavioral stress. However, the effect of behavioral stress on age-related synaptic plasticity in-vivo was primarily known. Here we found that the LTP induction in the hippocampal CA1 region of anesthetized rats obviously showed inverted-U shape related to ages (4, 10 and 74 weeks old rats), but low-frequency stimulation was unable to induce reliable long-term depression (LTD) in these animals. Furthermore, acute elevated platform (EP) stress enabled reliable LTD significantly and completely blocked LTP induction at these ages. Importantly, LTD after exposure to acute EP stress showed similar magnitude over these ages. The present results that stress enables LTD but impairs LTP induction at these three ages strengthen a view that stress experience-dependent LTD (SLTD) may underlie stress form of aberrant memories. (C) 2004 Elsevier B.V. All rights reserved.

中国角蟾亚科十一种的同工酶电泳研究(英文)

本文用同工酶电泳的方法分析了中国产角蟾亚科3属11种,共13个地理种群样本,以探讨它们的遗传多样性及系统关系。用于分析的酶共14种,由24个基因位点编码。经过酶带的分析和计算,得出了每个种群样本在每个基因位点上的等位基因频率（见表3）。根据基因频率的分布,计算得出了各种群样本的基因多样性指数——平均杂合率（H）（见表4）,结果表明,角蟾亚科的H值平均值为0.18, 在两栖动物中是属于很高的遗传多样性水平,根据基因频率的分布,计算了所有种群样本间的Nei’s遗传距（见表5）,并通过类平均法（UPGMA）重建了进化树（dendrogram）。分析结果支持将拟角蟾属（Ophryophryne）从角蟾属（Megophrys）中分出为独立属的观点;但是对短腿蟾属（Brachytarsophrys）是否为独立属提出了疑问。在角蟾属（Mesophrys）中,可以明显地看出3个组,它们中的种间亲缘关系比较近,这3个组分别是:①白颌大角蟾（M.lateralis）、大花角蟾（M.giganticus）和长肢角蟾（M.longipes）;②粗皮角蟾（M.palpebralespinneosa）、淡肩角蟾（M.boettgeri）...

艾滋病的传播与生殖道局部免疫

艾滋病的传播与生殖道局部免疫贲昆龙（中国科学院昆明动物研究所，昆明６５０２２３）引起人类艾滋病的人类免疫缺陷病毒（ＨＩＶ）可通过性交、血液、母婴和哺乳等方式传播，性交是主要的传播途径。据推测，全世界已感染ＨＩＶ的１，０００多万成年人当中，７５％是通过...

云南兔(Lepus comus)的染色体研究

用染色体分带技术分析表明云南兔2n=48, 常染色体中有6对中着丝点染色体、5对亚中着丝 点染色体、10对亚端着丝粒染色体和2对端着丝粒染色体。x染色体为一较大的亚中着丝粒染色体。c-带核型中, Nos.9,14,16,20染色体着丝粒c-带呈阴性, 而13,15,18呈很弱的阳性 。图版1表2参22(邓琳珠)

温度对烟蚜茧蜂发育、生殖的影响

烟蚜茧蜂发育速率与温度的关系符合逻辑斯蒂曲线,即25℃从卵至羽化所需历期最短(10.67d),30℃发育历期稍有延长(11.6d)。卵至羽化的发育起点温度为3.3℃,有效积温为266.0日度。烟蚜茧蜂雌蜂羽化当天即可产卵,在产卵期的前4天产出总卵量的90%(15-30℃);在6:30-22:30产出总卵量的80%。温度>25℃对烟蚜茧蜂雌蜂的寿命、生殖力,以及对僵蚜体重和羽化率均造成显著的负影响。烟蚜茧蜂雌蜂的寿命、性比、生殖力及僵蚜的体重和羽化率均在20℃时达最佳,结合发育历期的结果,认为该蜂大规模人工繁殖和释放的最佳温度范围是20-25℃。就研究结果在生物防治中的应用也进行了讨论。