蹄盖蕨科的亚科划分的修订

蹄盖蕨科Athyriaceae是蕨类植物中复杂的大科,分子系统学的研究证据表明它是一个自然类群。前人根据染色体的基数,将蹄盖蕨科划分为3个亚科,但没有得到分子证据的支持;本文依据分子系统学的研究结果,再结合形态特征,将该科重新划分为5个亚科：冷蕨亚科、蹄盖蕨亚科、对囊蕨亚科、双盖蕨亚科和轴果蕨亚科。     

黑龙江省蹄盖蕨科（Athyriaceae）植物的RAPD分析及其系统学意义

在形态分类研究的基础上,利用RAPD技术,对黑龙江省蹄盖蕨科植物6属9种共15个种群进行了遗传多样性分析,分析结果表明：（1）假冷蕨属应包括在蹄盖蕨属中（2）角蕨属与蹄盖蕨属,羽节蕨属与冷蕨属亲源关系较近（3）短肠蕨属为独立一属,与其它属亲源关系较远。根据黑龙江省蹄盖蕨科植物的DNA水平的研究结果,再结合其形态学特征,建议将黑龙江省蹄盖蕨科划分为3个亚科：冷蕨亚科（Cystopterioideae）包括2个属：冷蕨属（Cystopteris）和羽节蕨属（Cemnocarpium）。蹄盖蕨亚科（Athyrioideae）包括3个属：蹄盖蕨属（Athyrium）、假冷蕨属（Pseudocystopteris）和角蕨属（Cornopteris）。双盖蕨亚科（Diplazioideae）包括短肠蕨属（Alhntodia）。     

黑龙江省蹄盖蕨科(Athyriaceae)植物的RAPD分析及其系统学意义

在形态分类研究的基础上,利用RAPD技术,对黑龙江省蹄盖蕨科植物6属9种共15个种群进行了遗传多样性分析,分析结果表明：（1）假冷蕨属应包括在蹄盖蕨属中（2）角蕨属与蹄盖蕨属,羽节蕨属与冷蕨属亲源关系较近（3）短肠蕨属为独立一属,与其它属亲源关系较远。根据黑龙江省蹄盖蕨科植物的DNA水平的研究结果,再结合其形态学特征,建议将黑龙江省蹄盖蕨科划分为3个亚科：冷蕨亚科(Cystopterioideae)包括2个属：冷蕨属(Cystopteris)和羽节蕨属(Gymnocarpium)。蹄盖蕨亚科(Athyrioideae)包括3个属：蹄盖蕨属(Athyrium)、假冷蕨属(Pseudocystopteris)和角蕨属(Cornopteris)。双盖蕨亚科(Diplazioideae)包括短肠蕨属(Allantodia)。     

蹄盖蕨科的系统发育: 叶绿体DNA trnL-F区序列证据

蹄盖蕨科Athyriaceae是蕨类植物中一个复杂的大科,由于属间关系不甚清楚,该科分类系统还有一些问题,比如新蹄盖蕨、拟鳞毛蕨属、假冷蕨属、肠蕨属、短肠蕨属和菜蕨属的系统位置常有争议。根据蹄盖蕨科34种植物和3种外类群植物的叶绿体DNA trnL-F区序列建立了系统发育树,结果显示:1.trnL_F区序列分析的结果与rbcL基因序列分析的结果几乎一致。2.新蹄盖蕨属Neoathyrium Ching&Z.R.Wang不应成立,该属应与角蕨属Cornopteris Nakai合并。3.假冷蕨属Pseudo     

山东产蹄盖蕨科2属植物形态解剖学的研究

采用光镜和扫描电镜对山东分布的蹄盖蕨科2属(蹄盖蕨属和假蹄盖蕨属)7种植物的根、根茎、叶柄、叶轴、叶表皮、表皮毛和孢子囊进行了形态解剖学的系统研究.结果表明,在形态解剖学方面2属植物的共同特征为:根均为无髓中柱;叶柄基部的双柱型维管束向上渐靠近联合形成1个周韧型维管束;叶上下表皮垂周壁均呈波状;气孔主要为胞环型、周胞型或极附型.2属植物的不同特征是:蹄盖蕨属植物体无毛;而假蹄盖蕨属植物叶片和叶轴上均生有腺毛;蹄盖蕨属植物根皮层外侧为薄壁细胞,假蹄盖蕨属则为棕色厚壁细胞环.研究结果表明蹄盖蕨科为一个自然分类群,并支持假蹄盖蕨属的成立.     

中国蹄盖蕨属的研究I─属下分类

蹄盖蕨属是蕨类植物中分类最困难的大属之一,中国、喜马拉雅和日本为其分布中心。隶属于本属的种实际上是由蹄盖蕨科或广义蹄盖蕨属中其他属被划分出去以后剩余下来的种类集合而成的“大杂烩”,因此,它们被放在一起并非是一个单系起源的自然类群;属下不同类群分化的程度相差也很大,有的类群进化活跃,近缘种很多,有的类群则很孤立,所以属下单位所包括的种数相差悬殊;孢子周壁表面褶皱的有无在本属的属下分类中占有重要的位置。已发表的中国蹄盖蕨属植物名称约有３００多个,它们初步被处理为１１７种和一些变种和杂种,本文建议把这些种分为１４个组和１５个系。     

中国蹄盖蕨属的研究Ⅰ-属下分类

蹄盖蕨属是蕨类植物中分类最困难的大属之一,中国、喜马拉雅和日本为其分布中心。隶属于本属的种实际上是由蹄盖蕨科或广义蹄盖蕨属中其他属被划分出去以后剩余下来的种类集合而成的"大杂烩",因此,它们被放在一起并非是一个单系起源的自然类群;属下不同类群分化的程度相差也很大,有的类群进化活跃,近缘种很多,有的类群则很孤立,所以属下单位所包括的种数相差悬殊;孢子周壁表面褶皱的有无在本属的属下分类中占有重要的位置。已发表的中国蹄盖蕨属植物名称约有300多个,它们初步被处理为117种和一些变种和杂种,本文建议把这些种分为14个组和15个系。     

4种蹄盖蕨科植物配子体形态和发育的比较研究

利用光学显微镜详细观察蹄盖蕨科(Athyriaceae)2属4种植物,即蹄盖蕨属的尖头蹄盖蕨(Athyrium vidalii)、长柄蹄盖蕨(A.longius)和喜马拉雅蹄盖蕨(A.fimbriatum)以及亮毛蕨属的亮毛蕨(Acystopteris japonica)配子体发育过程,记录配子体各发育阶段的特征。4种植物的孢子都为单裂缝,两侧对称,孢子萌发类型为向心型,配子体发育类型为铁线蕨型,性器官都为薄囊蕨型,成熟原叶体为对称的心脏形,无毛状体;种间差异包括孢子纹饰、孢子萌发时间、配子体形成时间、丝状体长度、片状体和原叶体的形态以及性器官大小。     

国产蹄盖蕨属软刺蹄盖蕨组植物的研究

作者对国产蹄盖蕨属软刺蹄盖蕨组植物从形态分类和地理分布上进行了研究,共计载了23种。其中Athyrium densisorum,A.medogense和A.chingianum为新种,A.paranigripes为一新名称。文中还附有分类检索表,每种都有文献、异名和标本引证及地理分布。     

黑龙江省蹄盖蕨科三属(蹄盖蕨属、羽节蕨属及冷蕨属)的遗传多样性分析

利用7种随机引物对分布于黑龙江省不同区域蹄盖蕨科中的蹄盖蕨属,羽节蕨属及冷蕨属三属的遗传多样性进行了初步分析,对蹄盖蕨科各种基因组的DNA进行了PCR扩增,并对其RAPD谱带进行了统计处理,得出不同区域种类的多态位点百分率,结果表明蹄盖蕨科植物具有较高水平的遗传变异,其种类的分布对周围环境变化有着较强的适应能力。利用Shannon指数和Nei指数对其分析,确定了三属之间的属内种间的亲缘关系:蹄盖蕨属的大部分变异仍存在于种源内;冷蕨属中的冷蕨和山冷蕨种类之间具有一定的遗传变异;羽节蕨属中,欧洲羽节蕨和羽节蕨种间有较大的遗传变异。     

Bombyxin: An Insect Brain Peptide that Belongs to the Insulin Family

Bombyxin is a 5 kDa secretory brain peptide that belongs to the insulin family. Bombyxin of the silkmoth Bombyx mori can induce adult development when injected into brain-removed dormant pupae of the saturniid moth Samia cynthia ricini by activating the prothoracic glands to synthesize and release ecdysone. Bombyx bombyxin has been shown to lower the concentration of the major haemolymph sugar, trehalose, and to elevate the trehalase activity in the midgut and muscles in Bombyx, but the doses required to be effective are higher than the amounts in the feeding larvae. The exact physiological function of bombyxin in Bombyx itself is therefore still obscure, but its insulin-like structure suggests it has important roles. Bombyxin comprises a mixture of highly heterogeneous molecular forms whose amino acid sequences have 40% identity with human insulin. The Bombyx bombyxin gene encodes a precursor consisting of the signal peptide, B chain, C peptide, and A chain, in that order from the N terminus. So far, 32 bombyxin genes have been identified in Bombyx, and they are classified into 7 families, A to G, according to their sequence similarity. The bombyxin genes have no introns and cluster in unique distribution patterns. The gene arrangement in the cluster has been classified into three categories: gene pairs, gene triplets, and single genes. Nucleotide sequence analysis indicates that equal and unequal crossings-over and duplications may have generated these unique distribution patterns. The Bombyx bombyxin genes are expressed predominantly in the brain and at low levels in a number of other tissues. Genes of all 7 families are expressed in four pairs of the medial neurosecretory cells of the brain. Detailed examination indicated that only a limited number of genes in the A, B and C family members are expressed and that their expression shows a gene-arrangement-dependent pattern.     

Evidence for kinship between diverse G-protein coupled receptors.

In an earlier publication we described similarities at the primary sequence level between the first probable plant G-protein coupled receptor (GPCR) and three GPCR families (families A, B and F according to Kolakowski's classification) that were previously considered evolutionarily unrelated. Here we analyze further the relatedness among different GPCR families.By using PSI-BLAST, which is a search algorithm that is more potent in detecting weak similarities, one finds additional similarities between GPCR families that have not previously been described. Based on these comparisons, it is possible to divide all the GPCR families into one large clade and two smaller ones. The large clade includes the rhodopsin family (family A), the glucagon receptor family (family B), cyclic AMP receptors (family F), an Arabidopsis thaliana receptor, the Frizzled family and probably also the STE3 pheromone receptors (family E) and vomeronasal receptors type 1. The smaller clades consist of, in one case, BOSS and the GABA-B family of receptors (family C), and in the other the STE2 pheromone receptors (family D) alone. Although our findings are likely to reflect a common ancestry within each of these clades, whether or not two or all three of the clades also share an even more ancient ancestor between them remains an open question that cannot be answered from our present data.     

Study in vitro of the biosynthesis of Hb in alpha-thalassemic subjects of Puglia

An haematological study and haemoglobin biosynthesis in vitro carried out on the members of family from Ostuni (Apulia), three of which present Hb H in quantities varying from 26 to 28 and 29%, has been reported. On the basis of the haematological and biosynthetical data, the Authors think that the genetics of the alpha-thalassemia in the family under observation is similar to that observed in South East Asia according to the hypothesis of the existence of two alpha loci. The biosynthetical data fall into the values obtained by Kan and Coll. even if with slight differences.     

高迁移率族蛋白

高迁移率族蛋白(highmobilitygroupprotein,HMG蛋白)广泛存在于真核生物细胞中,因其在聚丙稀凝胶电泳中的高迁移率而得名。HMG蛋白是真核细胞基因调控的动力体现者,是真核细胞内继组蛋白之后含量最为丰富的一组染色质蛋白质,它们在染色质的结构与功能及基因表达调控过程中均发挥着重要作用。HMG蛋白家族可分为HMGA、HMGB和HMGN三类亚家族。现对HMG蛋白家族的三类亚家族蛋白HMGA、HMGB和HMGN的结构与功能进行综述。     

Lateral plate number in low‐plated threespine stickleback: a study of plasticity and heritability

In the threespine stickleback Gasterosteus aculeatus model system, phenotypes are often classified into three morphs according to lateral plate number. Morph identity has been shown to be largely genetically determined, but substantial within‐morph variation in plate number exists. In this study, we test whether plate number has a plastic component in response to salinity in the low‐plated morph using a split‐clutch experiment where families were split in two, one half raised in water at 0 and the other at 30 ppt salt. We find a small salinity‐induced plastic effect on plate number in an unexpected direction, opposite to what we predicted: Fish raised in freshwater on average have slightly more plates than fish raised in saltwater. Our results confirm that heritability of plate number is high. Additionally, we find that variance in plate number at the family level can be predicted from other family level traits, which might indicate that epistatic interactions play a role in creating the observed pattern of lateral plate number variation.     

Role of RepB in the replication of plasmid pJB01 isolated from Enterococcus faecium JC1

The plasmid pJB01 (GenBank Accession No. AY425961) isolated from the pathogenic bacterium, Enterococcus faecium JC1, is 2235 base pairs in length and consists of a putative double-strand origin (dso), a single-strand origin, a counter-transcribed RNA, and three open reading frames. A comparison of a few replication factors and motifs, bind and nic regions, for replication initiation on the nucleotide sequence level revealed that it belongs to the pMV158 family among RC-replicating plasmids. A runoff DNA synthesis assay demonstrated that nicking occurred between G525 and A526, which is located on the internal loop of a putative secondary structure in the dso. Unlike all the other plasmids of the pMV158 family having two or three direct repeats, pJB01 has three non-tandem direct repeats of 5'-CAACAAA-3' separated by four nucleotides, as the RepB-binding site in the dso. Moreover, the nick site on the internal loop is located at 77 nucleotides upstream from the RepB-binding region. Irrespective of the structural difference of direct repeats from other members of the pMV158 family, we think, it is still a new member of this plasmid family. The introduction of mutations in conserved regions of RepB confirmed that RepB N-moiety is important for nicking/nick-closing activity. Within N-moiety, especially all of the motif R-III, the Y100 in R-IV and Y116 in R-V residues, played particularly critical roles in this activity, however, for its binding, both of the N- and C-moieties of RepB were needed.     

Linguistic analysis in phylogeny estimation: a case study of mtDNAs of Bovidae

Molecular phylogenetic studies are executed by the alignment of protein or nucleotide sequences, followed by the construction of trees according either to distance, parsimony or maximum likelihood methods. Linguistic analysis was investigated here as an alternative method to aligning sequences. In an empirical study, we inferred trees for a variable number of Bovidae and sister taxa based on three different mitochondrial orthologous sequences. Comparison of our results with existing phylogenies indicated that the method, except for some still disputable points, was able to establish sensible systematic relationships, similar to patterns of radiation of the family found in recent studies.     

Acyclic permutants of naturally occurring cyclic proteins. Characterization of cystine knot and beta-sheet formation in the macrocyclic polypeptide kalata B1

Kalata B1 is a prototypic member of the unique cyclotide family of macrocyclic polypeptides in which the major structural features are a circular peptide backbone, a triple-stranded beta-sheet, and a cystine knot arrangement of three disulfide bonds. The cyclotides are the only naturally occurring family of circular proteins and have prompted us to explore the concept of acyclic permutation, i.e. opening the backbone of a cross-linked circular protein in topologically permuted ways. We have synthesized the complete suite of acyclic permutants of kalata B1 and examined the effect of acyclic permutation on structure and activity. Only two of six topologically distinct backbone loops are critical for folding into the native conformation, and these involve disruption of the embedded ring in the cystine knot. Surprisingly, it is possible to disrupt regions of the beta-sheet and still allow folding into native-like structure, provided the cystine knot is intact. Kalata B1 has mild hemolytic activity, but despite the overall structure of the native peptide being retained in all but two cases, none of the acyclic permutants displayed hemolytic activity. This loss of activity is not localized to one particular region and suggests that cyclization is critical for hemolytic activity.     

Studies of Pollen Morphology and Its Systematic Position in the Order Piperales

The pollen morphology of 25 species and 10 genera of Piperales (Chloranthaceae, Piperaceae and Saururaceae) has been examined under light microscope, of which 7 species were observed under scanning electron microscope and 1 species, Hedyosmum orentale Merr. & Chun transmision electron microseope. Three principal types of pollen were found: anasulcate (mostly) (sometime trichotomosulcate), inaperturate (partly) and multicolpoidate (partly). The present article has discussed the palynological data mainly in relation to the classification and the systematic position of Cbloranthaceae and also deals with the systematic position of the order Piperales. The present author agrees to put the family Chloranthaceae into the order Piperales. Because this family differs from Piperaceae and Saururaceae in pollen morphology, therefore, Chloranthaceae should raise to the level of suborder. Among three families of the order Piperales, the present author considers Chloranthaceae to be the most primitive family, on account of the following reasons: 1. The family Chloranthaceae shows the characteristics of primitive entomophilous plants in the sculpture of exine, while in the other two families, Piperaceae and Saururaceae, their exine is almost smooth and represents wind-pollenated plants; 2. Pollen of the family Chloranthaceae are larger than those of Piperaceae and Saururaceae; 3. The fossil pollen Clavatipollenites has been proved to be one of the most primitive angiosperms on the earth, that it is known, it occurred in the early Cretaceous, and at that time ferns and gymnosperms were predominant, while the Chloran- thaceae has already existed at that time; 4. Sarcandra of Chloranthaceae possesses the characters of a vesselless secondary xylem and a delayed development of embryo. Thus, Chloranthaceae would be considered as the most primitive family in the order Piperales. The systematic position of the order Piperales is also discussed. Itutehinson makes a point that order Ranales is more primitive than Piperales, and his system is arranged in the following order: Ranales → Piperales → to climax family Chloranthaceae. This view-point, however, is net supported by the palynological data. Pollen morphology shows that Piperales is more primitive than Ranales, because the pollen in Piperales possess the ancient aperture type of Pteridospermes, i.e., the type of anasulcate aperture is prevailing in Piperales, moreover, pollen grains of Ranales are mainly tricolpate type, and tricolpate pollen is a characteristic of typical angiosperms. In addition, the Piperales possesses a series of characters that are common among monocots, but rare among dicots. As the divergence between dicer and monocot took place in the early Cretaceous, their ancestor possesses common chararcters both of dicots and monocots while the extant Piperales still possess many characters of monocots that indicate it is much nearer to the point of divergence, and it explains that the Piperales is closely related to the ancestor of monocots and dicers Piperales, therefore, is more primitive than Ranales.