金银花花形基因的发掘及生物信息学分析

金银花作为我国重要的中药材,具有消炎、抗菌、抗病毒、抗氧化、防癌等多种功效。随着金银花市场供需矛盾日益加剧,通过分子标记辅助选择育种方法来培育高产优质品种势在必行。通过NCBI的Blast工具扫描金银花蛋白组数据发掘花形候选基因,并执行候选基因的亲缘关系分析、结构域分析、表达模式分析、理化性质分析、蛋白质结构预测等一系列生物信息学分析。依据拟南芥调控花形的ABE类基因,通过NCBI-Blast工具扫描金银花氨基酸序列,筛选出包含MADS结构域的8个调控花形的金银花候选基因。经LjaFGD表达模式分析发现,金银花的花中GWHGAAZE016592和GWHGAAZE014905表达量显著高于其他部位,可能正向调控金银花花形。GWHGAAZE014905是一个包含MADS结构域的调控花器官发育的B类基因;GWHGAAZE016592是AP3同源基因。生物信息学分析发现,GWHGAAZE016592和GWHGAAZE014905均是稳定的亲水蛋白,属于非分泌蛋白,包括Motif1、Motif3、Motif4、Motif2、Motif6和Motif5,蛋白质三级结构模板为6byy.2.A和4ox0.2.C。GWHGAAZE014905被定位到细胞核上,而GWHGAAZE016592被定位到叶绿体上,且包含1个位于151~173 bp的跨膜螺旋区域,属于膜蛋白。研究结果为分子标记辅助选择方式培育道地高产优质金银花品种提供了基因资源和分子标记。     

Induction and axial patterning of the neural plate: Planar and vertical signals

In this review I summarize recent findings on the contributions of different cell groups to the formation of the basic plan of the nervous system of vertebrate embryos. Midline cells of the mesoderm—the organizer, notochord, and prechordal plate—and midline cells of the neural ectoderm—the notoplate and floor plate—appear to have a fundamental role in the induction and patterning of the neural plate. Vertical signals acting across tissue layers and planar signals acting through the neural epithelium have distinct roles and cooperate in induction and pattern formation. Whereas the prechordal plate and notochord have distinct vertical signaling properties, the initial anteroposterior (A-P) pattern of the neural plate may be induced by planar signals originating from the organizer region. Planar signals from the notoplate may also contribute to the mediolateral (M-L) patterning of the neural plate. These and other findings suggest a general view of neural induction and axial patterning. © 1993 John Wiley & Sons, Inc.     

AUXOSPORULATION IN CYCLOTELLA OCELLATA (BACILLARIOPHYCEAE) UNDER NATURAL AND EXPERIMENTAL CONDITIONS1

Growth and sexual reproduction in a population of Cyclotella ocellata Pantocseck were studied during one annual cycle in a reservoir and in short-term enclosure experiments performed in situ involving different nutrient conditions and concentrations of zooplankton species. Three phases of auxosporulation in this diatom were distinguishable morphologically: 1) preauxospore, from the beginning of zygote formation until the valves were longitudinally separated, 2) primary auxospore, when the zygote grew too large to fit inside the valves and before it reached its full size, and 3) mature auxospore, characterized by a well-developed, markedly scalloped edge. Under experimental and natural conditions, sexual reproduction was associated with changes in cell size. In the natural system, the auxospore appeared to act as a resting structure during conditions adverse for population growth. A threshold population of small cells appeared to be necessary for sexual reproduction in the natural system, whereas auxosporulation was associated with phosphorus fertilization in the enclosures. In both environments only cells smaller than 9.5 μm in diameter were capable of auxospore formation. Our results suggest that, once having reached the critical cell size, the factors that trigger sexual reproduction may depend on ambient environmental conditions.     

Between Xylem and Phloem: The Genetic Control of Cambial Activity in Plants

Abstract: Post-embryonic development is controlled by two types of meristems: apical and lateral. There has been considerable progress recently in understanding the function of root and shoot apical meristems at the molecular level. Knowledge of analogous processes in the lateral, or secondary, meristems, i.e. the vascular cambium or cork cambium, is, however, rudimentary. This is despite the fact that much of the diversity in the plant kingdom is based on the differential functions of these meristems, emphasizing the importance of lateral meristems in the development of different plant forms. The vascular cambium is particularly important for woody plants, but it also plays an important role during the development of various herbaceous species, such as Arabidopsis thaliana. In this review, we focus on the two basic functions of cambial activity: cell proliferation and pattern formation.     

How New Guinea rainforest flower resources vary in time and space: Implications for nectarivorous birds

Abstract Variability in spatial and temporal patterning of flowering by populations of rainforest trees fed upon by honeyeaters and flower-visiting parrots was studied for 2 years in lowland tropical hill forest in Papua New Guinea. All 2200 trees in a 3 ha plot were tagged, identified, mapped and monitored monthly. Of 274 tree species present, 86 flowered during the course of the study; during any given month, approximately 20% of the species flowering that month were visited by nectarivorous birds. Results showed that overall flower resources (total number of species, and number of bird-pollinated species, individuals and flowers) fluctuated during the year, decreased during the dry season and increased during the wet season. In addition, there was a wide range of temporal variation within and among tree species in length and timing of flowering period, percentage of each conspecific population flowering from year to year, and degree of synchrony among flowering conspecifics. Spatial dispersion of tree populations also varied, from clumps to scattered single individuals. Resident bird species were correlated with synchronously flowering trees, whereas nomadic bird species were correlated with asynchronously flowering trees. Resident birds were also associated with smaller blooming displays per tree, whereas nomadic birds were associated with trees that bloomed massively. There was no correlation between avian nomadism and spatial dispersion of tree populations. Thus nomadic birds seem to range in search of rich but unpredictable resources; resident birds may rely more on predictable, but smaller resources.     

Low frequency of extra-pair paternity in two colonies of the socially monogamous short-tailed shearwater Puffinus tenuirostris

The short-tailed shearwater is a colonially nesting, socially monogamous seabird. Little is known about mate fidelity and breeding behaviour in this species because breeding birds are nocturnal on land and spend much of their time within subterranean nesting burrows. Colonial breeding and extended sperm storage create opportunities for extra-pair copulations which may form a significant component of the mating strategy in this species. Multilocus DNA fingerprinting was used to examine the genetic relationship between nestlings and the male and female nest attendants in 83 burrows from two distinct breeding colonies. Genetic analyses identified nine nestlings, approximately equally distributed between the two colonies, that were not related to the attendant pair male in those burrows, implying extra-pair paternity through extra-pair copulations. These results are used retrospectively to discuss the characteristics of extra-pair copulations and extra-pair fertilizations and the implications for estimates of life-time reproductive success in the short-tailed shearwater.     

野生猕猴声行为的研究

本文通过在华南四省区对四个野生种群猕猴声行为的观察和现场录音,对它们的叫声声学特性,行为模式和其它个体对其相应的行为反应进行了定量的分析研究,并得出１１种不同的声行为,这些声行为有相互不同的声学特性,不同的行为模式并引起其它个体相应的行为反应,从而起着通讯的作用。叫声在猕猴的声行为通讯中,一些借助视觉提示,至少以不同的刺激度来“表示”某一类事物,并得到个体间的“共识”有些甚至无需视觉提示而单独传递     

Mutations affecting pigmentation and shape of the adult zebrafish

 Mutations causing a visible phenotype in the adult serve as valuable visible genetic markers in multicellular genetic model organisms such as Drosophila melanogaster, Caenorhabditis elegans and Arabidopsis thaliana. In a large scale screen for mutations affecting early development of the zebrafish, we identified a number of mutations that are homozygous viable or semiviable. Here we describe viable mutations which produce visible phenotypes in the adult fish. These predominantly affect the fins and pigmentation, but also the eyes and body length of the adult. A number of dominant mutations caused visible phenotypes in the adult fish. Mutations in three genes, long fin, another long fin and wanda affected fin formation in the adult. Four mutations were found to cause a dominant reduction of the overall body length in the adult. The adult pigment pattern was found to be changed by dominant mutations in wanda, asterix, obelix, leopard, salz and pfeffer. Among the recessive mutations producing visible phenotypes in the homozygous adult, a group of mutations that failed to produce melanin was assayed for tyrosinase activity. Mutations in sandy produced embryos that failed to express tyrosinase activity. These are potentially useful for using tyrosinase as a marker for the generation of transgenic lines of zebrafish. Received: 17 June 1996 / Accepted: 15 July 1996     

青海湖裸鲤寄生舌状绦虫的空间格局研究

舌状绦虫裂头蚴只寄生在体长小于２２０ｍｍ的青海湖裸鲤中,其种群在宿主种群中呈聚集分布。其聚集分布的强度随寄生虫种群平均密度的增加而降低。由于舌状绦虫在宿主体腔生长,产生明显的空间拥挤效应,可能导致宿主死亡或被食鱼鸟类捕食而转移到终末宿主中。在体长小于１２０ｍｍ的宿主中,密度依赖的死亡过程可能是使聚集强度降低的原因;而体长１４０－２００ｍｍ的鱼中,则是非密度依赖的全死过程使聚集强度增加．