中国贝类染色体研究现状与进展

对我国已报道的81种贝类染色体研究进行了综述,并结合贝类分子系统进化研究成果,探讨了我国贝类染色体数目与染色体组成的进化趋势。     

The maturation of the salmon GnRH system and its regulation by gonadal steroids in masu salmon

Pituitary gonadotropin (GTH) secreting cells and brain gonadotropin-releasing hormone (GnRH) secreting neurons are known to be subjected to feedback control by gonadal steroid in teleosts. In masu salmon, Oncorhynchus masou, salmon GnRH (sGnRH) neurons in the ventral telencephalon (VT) and the preoptic area (POA) are involved in the control of GTH cells because sGnRH synthesis in these areas is activated with gonadal maturation. In this study, we attempted to clarify mechanisms of feedback control of sGnRH neurons by gonadal steroids. We examined the effects of 17-methyltestosterone (MT) on sGnRH synthesis in yearling and 2-year-old female fish (which were immature during experimentation in May), and the effects of castration on sGnRH synthesis in underyearling precocious male fish in August. sGnRH synthesis in the POA, but not in the VT, was increased by MT administration in 2-year-old females only, indicating higher sensitivity to MT in the preoptic sGnRH neurons. Castration increased sGnRH synthesis in the VT but not in the POA. These results suggest that sGnRH neurons in the VT and those in the POA are differentially regulated by gonadal steroids.     

利用InDel标记鉴定水稻籼粳交衍生株系的籼粳属性

通过籼粳杂交培育了9个水稻品系,进行形态指数法和分子标记法籼粳属性鉴定.结果表明,GY908、GY1128、GY1124和GY2888属籼稻类型,GY926和GY2750属偏籼类型,GY726、GY770、GY1134属偏粳类型,与分子标记的遗传距离聚类分析结果一致.说明通过籼粳渐渗手段,培育中间型水稻品系,对丰富水稻新材料的遗传背景具有重要意义.     

氯酸钾促龙眼成花机理的研究进展

“KClO3-longan model system”除了具有生产应用上的意义,更具有重要的科研潜力和科研价值.对氯酸钾促龙眼成花的植物生理学及分子生物学机理研究进行简介.     

金鱼头瘤形成相关基因差减文库的构建与分析

采用差减抑制杂交技术(SSH)以1龄红狮头金鱼(Carassius auratus)的头瘤组织为检测子(Tester),40日龄红狮头金鱼幼鱼的头顶上皮组织为驱动子(Driver),构建金鱼头瘤相关基因的差减cDNA文库。以鲫管家基因α-tubilin为参照检测差减效率,结果表明该文库差减效率达210倍,效率较高。随机挑选阳性克隆进行接头特异引物的PCR检测,结果表明插入片段均在0.1~2.0kb之间。利用斑点杂交对PCR检测结果为单一条带的阳性克隆进行筛选并测序,获得高差异性的有效序列93条。通过生物信息学方法对文库序列进行比对、分类和注释,发现若干结缔形成基因和原癌/抑癌基因等与金鱼头瘤形成相关的功能基因,表明cDNA文库构建成功。     

野鸢尾和射干种间杂交F_2代主要性状变异分析

通过观测野鸢尾(Iris dichotoma)×射干(I.domestica)杂交F2代群体(n=61)中每一个体的株高、花径、花数、花色和彩斑等14个表型性状,对F2代与双亲性状差异、群体性状变异、主要性状间遗传相关性及花色遗传变异等方面进行分析,以明确F2群体性状变异特点,指导夏季开花鸢尾育种实践。结果表明:F2代12个性状中,8个性状的观测值居于双亲之间;除花朵直径和花朵数量外,花葶长等10个性状基本均呈正态分布,属多基因控制的数量性状;性状之间存在一定相关性,外花被长与内花被长和外花被宽与内花被宽的相关度最高,相关系数分别为0.821和0.734,趋于连锁遗传;对颜色性状的分析结果表明花色和花瓣彩斑的遗传由不同基因调控,但都是由多个基因共同控制。野鸢尾×射干F2代群体的花朵直径、花朵数量、花葶长及花色变异丰富,利于大花、多花、花葶矮生和奇异花色的优良单株的选择。     

水稻OsRbohB基因原位杂交载体的构建 及其在花药中的表达分析

为研究水稻呼吸爆发氧化酶基因OsRbohB在花药中特定的表达模式,构建了原位杂交探针载体Pbsk-OsRbohB,通过体外转录获得DIG标记的原位杂交探针,以不同发育时期的水稻花药为材料进行原位杂交试验.结果发现,OsRbohB基因主要在水稻花药发育第8～10期的绒毡层和小孢子中表达,在第9期达到高峰,第10期开始下降.推测OsRbohB主要参与水稻花药早期的发育,该研究为进一步研究OsRbohB基因在水稻活性氧产生中的作用提供参考.     

Development and application of fluorescence in situ hybridization (FISH) method for simple and rapid identification of the toxic dinoflagellates Alexandrium tamarense and Alexandrium catenella in cultured and natural seawater

ABSTRACT:   The toxic dinoflagellates Alexandrium tamarense (Lebour) Balech and A. catenella (Whedon and Kofoid) Balech produce potent neurotoxins, such as saxitoxin and gonyautoxin and have been mainly responsible for paralytic shellfish poisoning (PSP) in Japan. To prevent a negative effect on the fishery industry, it is necessary to identify these toxic species precisely and rapidly before and during the bloom. In this paper, a rapid and simple protocol of a fluorescence in situ hybridization (FISH) method using ribosomal RNA (rRNA)-targeted probes has been established for identifying the cultured strains and natural cells of A. tamarense and A. catenella . Using the FISH method established in this study, it was possible to identify these toxic species species-specifically and rapidly, within 30 min. The procedure of detection constituted three steps: (i) fixation/dehydration; (ii) hybridization; and (iii) washing; this made the identification simple. Moreover, this method did not require either special techniques or equipment, and the cost for detection was low. The specificity, rapidity, and simplicity of the developed method suggest that it might be useful for routine monitoring of these toxic microalgae.     

奥利亚罗非鱼（♀）、鳜（♂）及其子代间遗传关系的研究

罗非鱼生长快、味道好,是人们喜爱的鱼类,现已是世界性养殖鱼类,但它不能忍受低温,因此影响其养殖业的进一步发展。鳜则是名贵性鱼类,但其终生摄食活的鱼虾,这也限制了其养殖的发展。奥利亚罗非鱼(Oreochromisaurea)属鲈形目、鲡鱼科,鳜(Sinipercachuatsi)属鲈形目、脂科,它们间的杂交为科间杂交。鱼类科间杂交成功率很低,种间杂交有时可获得具有双亲性状的杂种鱼,有时也可发生雌核发育[1]。本研究中奥利亚罗非鱼雌鱼性染色体为ZW,其卵子如能在鳜精子刺激下行雌核发育,则可在短时间获得奥利亚罗非鱼纯系。在本文中,利用RAPD标记,对…     

Identification of a telomere sequence type in three sponge species (Porifera) by fluorescence <Emphasis Type="Italic">in situ</Emphasis> hybridization analysis

The telomere sequence type (TTAGGG)_n is known to be distributed in various phyla in the Animalia and in Mastigophora (Protista). However, the telomere type of Porifera (sponges), a phylum comprising the lowest multicellular animals, has not been reported. In this study, we examined the three sponge species Leucetta chagosensis, Halichondria japonica, and Halichondria panicea for the presence of the telomere type (TTAGGG)_n by fluorescence in situ hybridization (FISH). The oligonucleotide probe (TTAGGG)₇ clearly displayed signals on the interphase nuclei of all three sponges. In contrast, the (TTAGG)₇ probe, which has one base fewer than (TTAGGG)₇, did not display the signals. These results suggest that the telomeres of the three sponges consist of (TTAGGG)_n, which is identical to the sequence type found in many higher multicellular animals and in Mastigophora. Additionally, this is the first study to reveal a telomere sequence type for Porifera. Moreover, these results suggest that Porifera are phylogenetically related to Mastigophora, and supports the general theory that Porifera evolved from Mastigophora. Further, this study strongly suggests that the origin of the (TTAGGG)_n telomere sequence is to be found in a common ancestor of either the Bilateria and Porifera, or the Protista.