Mapping chromosomal homologies between humans and two langurs (Semnopithecus francoisi and S-Phayrei) by chromosome painting

Chromosomal homologies were established between human and two Chinese langurs (Semnopithecus francoisi, 2n=44, and S. phayrei, 2n=44) by chromosome painting with chromosome-specific DNA probes of all human chromosomes except the Y. Both langur species showed identical hybridization patterns in addition to similar G-banding patterns. In total, 23 human chromosome-specific probes detected 30 homologous chromosome segments in a haploid langur genome. Except for human chromosomes 1, 2, 6, 16 and 19 probes, which each gave signals on two non-homologous langur chromosomes respectively, all other probes each hybridized to a single chromosome. The results indicate a high degree of conservation of chromosomal synteny between human and these two Chinese langurs. The human chromosome 2 probe painted the entire euchromatic regions of langur chromosomes 14 and 19. Human chromosome 1 probe hybridized to three regions on langur autosomes, one region on langur chromosome 4 and two regions on langur chromosome 5. Human 19 probe hybridized on the same pattern to one region on chromosome 4 and to two regions on langur chromosome 5, where it alternated with the human chromosome 1 probe. Human 6 and 16 probes both hybridized to one region on each of the two langur autosomes 15 and 18. Only two langur chromosomes (12 and 21) were each labelled by probes specific for two whole human chromosomes (14 and 15 and 21 and 22 respectively). Comparison of the hybridization patterns of human painting probes on these two langurs with the data on other Old World primates suggests that reciprocal and Robertsonian translocations as will as inversions could have occurred since the divergance of human and the langurs from a common ancestor. This comparison also indicates that Asian colobines are karyotypically more closely related to each other that to African colobines.

Evolution of different oligorneric glycyl-tRNA synthetases

There are two oligomeric types of glycyl-tRNA synthetases (GlyRSs) in genome, the alpha(2)beta(2) tetramer and alpha(2) dimer. Here, we showed that the anticodon-binding domains (ABDs) of dimeric and tetrameric GlyRSs are non-homologous, although their catalytic central domains (CCDs) are homologous. The dimeric GlyRS_ABD is fused to the C-terminal of CCD in alpha-subunit, but the tetrameric GlyRS_ABD is to the C-terminal in beta-subunit during evolution. Generally, one species only contains one oligomeric type of GlyRS, but the both oligomeric GlyRSs with the multiple homologous domains can be observed in Magnetospirillum magnetotacticum genome, nevertheless, these homologous domains are probably from different genomes. (C) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Repetitive element-mediated recombination as a mechanism for new gene origination in Drosophila

Previous studies of repetitive elements (REs) have implicated a mechanistic role in generating new chimerical genes. Such examples are consistent with the classic model for exon shuffling, which relies on non-homologous recombination. However, recent data

Effects of exogenous double-stranded RNA on the basonuclin gene expression in mouse oocytes

In plants and less-advanced animal species, such as C.elegans, introduction of exogenous double-stranded RNA (dsRNA) into cells would trigger degradation of the mRNA with homologous sequence and interfere with the endogenous gene expression. It might represent an ancient anti-virus response which could prevent the mutation in the genome that was caused by virus infection or mobile DNA elements insertion. This phenomenon was named RNA interference, or RNAi. In this study, RNAi was used to investigate the function of basonuclin gene during oogenesis. Microinjection of dsRNA directed towards basonuclin into mouse germinal-vesicle-intact (GV) oocytes brought down the abundance of the cognate mRNA effectively in a time- and concentration-dependent manner. This reduction effect was sequence-specific and showed no negative effect on other non-homologous gene expression in oocytes, which indicated that dsRNA can recognize and cause the degradation of the transcriptional products of endogenous basonuclin gene in a sequence-specific manner. Immunofluorescence results showed that RNAi could reduce the concentration of basonuclin protein to some extent, but the effect was less efficient than the dsRNA targeting towards tPA and cMos which was also expressed in oocytes. This result might be due to the long half life of basonuclin protein in oocytes and the short reaction time which was posed by the limited life span of GV oocytes cultured in vitro. In summary, dsRNA could inhibit the expression of the cognate gene in oocytes at both mRNA and protein levels. The effect was similar to Knock-out technique which was based on homologous recombination. Furthermore, hairpin-style dsRNA targeting basonuclin gene could be produced by transcription from a recombinant plasmid and worked efficiently to deplete the cognate mRNA in oocytes. This finding offered a new way to study the function of basonuclin in the early stage of oogenesis by infection of primordial oocytes with the plasmid expressing hairpin-style basonuclin dsRNA.

Akrokolioplax, a new genus of Southeast Asian labeonine fishes (Teleostei : Cyprinidae)

Akrokolioplax, new genus, is erected for the reception of Epalzeorhynchos bicornis Wu, 1977. It shares with the remaining species of Epalzeorhynchos what have usually been called "rostral lateral lobes" on the snout, which are non-homologous structures used to distinguish the two genera from all other Labeoninae genera. Akrokolioplax and Epalzeorhynchos differ in the position and structure of these lobes, and also in the morphology of the oromandibular structures. A detailed redescription is also provided for the type species of this monotypic genus, A. bicornis. It is presently known from the upper Salween River (=Nu Jiang in Chinese) basin in Yunnan (South China), Myanmar and Thailand.

Synaptonemal complex analysis in spermatocytes of diploid and triploid Chinese shrimp Fenneropenaeus chinensis

A modified surface spreading technique for synaptonemal complex (SC) analysis was tested to assess the process of chromosome synapsis in spermatocytes of diploid and induced triploid Fenneropenaeus chinensis. Spermatocytes of diploid shrimp showed typical morphological characteristics of eukaryote SC, with complete synapsis of bivalents. No recognizable bivalent associated with sex chromosomes was observed in spermatocytes of diploid shrimp. However, differences in morphology of SC, including unsynapsed univalents, bivalents, totally paired trivalents with non-homologous synapsis, partnerswitches and triple synapsis were identified at early pachytene stage of triploid spermatocytes. Triple synapsis was especially common at late pachytene stage in spermatocytes of triploid shrimp. The observed abnormal synapsis behavior of chromosomes in spermatocytes indicated that triploid male shrimp may find it difficult to develop normal haploid sperm. (C) 2008 Elsevier Ltd. All rights reserved.

Donut-Shaped Fingerprint In Homologous Polypeptide Relationships-A Topological Feature Related To Pathogenic Structural Changes In Conformational Disease

Features of homologous relationship of proteins can provide us a general picture of protein universe, assist protein design and analysis, and further our comprehension of the evolution of organisms. Here we carried Out a Study of the evolution Of protein molecules by investigating homologous relationships among residue segments. The motive was to identify detailed topological features of homologous relationships for short residue segments in the whole protein universe. Based on the data of a large number of non-redundant Proteins, the universe of non-membrane polypeptide was analyzed by considering both residue mutations and structural conservation. By connecting homologous segments with edges, we obtained a homologous relationship network of the whole universe of short residue segments, which we named the graph of polypeptide relationships (GPR). Since the network is extremely complicated for topological transitions, to obtain an in-depth understanding, only subgraphs composed of vital nodes of the GPR were analyzed. Such analysis of vital subgraphs of the GPR revealed a donut-shaped fingerprint. Utilization of this topological feature revealed the switch sites (where the beginning of exposure Of previously hidden "hot spots" of fibril-forming happens, in consequence a further opportunity for protein aggregation is Provided; 188-202) of the conformational conversion of the normal alpha-helix-rich prion protein PrPC to the beta-sheet-rich PrPSc that is thought to be responsible for a group of fatal neurodegenerative diseases, transmissible spongiform encephalopathies. Efforts in analyzing other proteins related to various conformational diseases are also introduced. (C) 2009 Elsevier Ltd. All rights reserved.

Molecular evolution of connective tissue growth factor in Cyprinidae (Teleostei : Cypriniformes)

Connective tissue growth factor (CTGF) plays an important role in regulation of cell growth, differentiation, apoptosis and individual development in animals. The study of sequences variation and molecular evolution of CTGF gene across various species of the cyprinid could be helpful for understanding of speciation and gene divergence in this kind of fish. In this study, 19 novel sequences of CTGF gene were obtained from the representative species of the family Cyprinidae using PCR amplification, cloning and sequencing. Phylogenetic relationships of Cyprinidae were reconstructed by neighbor-joining (NJ), maximum parsimony (MP), maximum likelihood (ML) and Bayesian method. Oryzias latipes from the family Cyprinodontidae was assigned to be the outgroup taxon. Leuciscini and Barbini were clustered into the monophyletic lineages, respectively, with the high nodal supports. The estimation of the ratio of non-synonymous to synonymous substitution (dN/dS) for the various branches indicated that there stood the different evolution rates between the Leuciscini and the Barbini. With the ratio of dN/dS of the Leuciscini being lower than that of the Barbini, species within the Barbini were demonstrated to be subjected to the relatively less selection pressure and under the relaxable evolution background. A 6 by indel (insertion/deletion) was found at the 5' end of CTGF gene of Cyprinidae, and this 6 by deletion only appeared in the Leuciscini, which is a typical characteristic of the Leuciscini and provides evidence for the monophylogeny of the Leuciscini. For the amino acid sequences of CTGF protein, the most variations and indels were distributed in the signal region and IGFBP region of this protein, implying that these variations were correlated with the regulation of the CTGF gene expression and protein activity. (c) 2007 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.

中国松鼠科 Sciuridae (Non-flying squirrels) 动物的分类和分布及系统发育研究

松鼠科隶属于哺乳纲、啮齿目，是一类世界广布性动物，全世界共计36 属 234 种。本文通过形态分析及分子生物学方法，研究了我国松鼠科动物的分类及 系统发育关系，内容包括以下两个方面： 一、中国松鼠科动物的分类 本研究查看了中科院昆明动物研究所、中科院动物研究所、云南大学、四川 省林业科学研究院、四川大学、陕西师范大学、陕西动物研究所、西北大学、上 海自然历史博物馆、广东昆虫所馆藏该科各类群标本。同时，结合相关文献，对 各类群的外形特征进行了详细的描述和系统分类整理，我国共计10 属34 种。测 取可量性状数据共计20800 个（完整头骨共计1300 号），而且还运用多变量及单 变量分析方法进行数据分析，对部分类群的种下分类结果进行分析：1.探讨了分 布于中国境内的明纹花鼠（Tamiops mcclellandii）3 亚种的有效性。2.研究了 隐纹花鼠（Tamiops swinhoei）在中国的分化并描记了分布于四川马尔康地区的 隐纹花鼠为一新亚种（Tamiops swinhoei markamensis）。3.描记了分布于云南 省东北部昭通地区的赤腹松鼠为一新亚种：昭通亚种（Callosciurus erythraeus zhaotongensis）。4. 提出了分布于云南省无量山区的泊氏长吻松鼠为一新亚种： 无量山亚种（Dremomys pernyi wuliangshanensis）。 二、中国松鼠科动物的系统发育研究 2004－2005 年相继到滇西北高黎贡山、香格里拉，滇西南临沧地区，滇东 南马关、麻栗坡、富宁，滇东北昭通地区进行标本采集，基本收集到我国南方松 鼠科属、种样品进行分子生物学研究。 1.中国松鼠科动物各属的系统发育关系 在分析线粒体细胞色数b 基因（1040bp）序列的基础上，运用贝叶斯法 （Bayesian phylogenetic reconstruction approaches）、最简约法（Maximum parsimony method）、邻接法（Neighbor Joining method）构建中国松鼠科动物 所有属间系统发育树。结果表明：所分析的10 属分别聚集为3 群，巨松鼠属Ratufa单独成为一群，丽松鼠属Callosciurus、长吻松鼠属Dremomys、花松鼠属 Tamiops 以及线松鼠属Menetes 成为一群，松鼠属Sciurus、岩松鼠属 Sciurotamias、花鼠属Tamias、旱獭属Marmota 以及黄鼠属Spermophilus 成 为一群。在此基础上我们进一步探讨了中国松鼠科动物的分化与环境变化的关 系。 2.长吻松鼠属的系统发育关系 在分析线粒体细胞色数b 基因（378bp）序列的基础上，我们重建了长吻松 鼠属内5 个类群间的系统发育关系，结合对5 类群外部形态特征的详细比较，我 们探讨并论证了红腿长吻松鼠、橙喉长吻松鼠作为种的地位的有效性，同时论证 了该属内泊氏长吻松鼠最早分化，其次为橙腹长吻松鼠，第三是红腿长吻松鼠， 红颊长吻松鼠和橙喉长吻松鼠是最后分化的类群。

Isothermal and non-isothermal crystallization kinetics of syndiotactic polypropelene

Isothermal and non-isothermal crystallization kinetics of a syndiotactic polypropylene(sPP) sample synthesized by new metallocene catalyst at different annealing temperatures and different cooling rates have been investigated by using differential scanning calorimetry(DSC) and density analysis. The equilibrium melting temperature( T-m(0)) is 158 degrees C by Hoffman-Weeks method. The equilibrium heat of fusion(Delta H-m(0)) is 88J/g in terms of the density analysis and DSC methods. The lateral and end surface free energies derived from the Lauritzen-Hoffman spherulitic growth rate equation are sigma = 5.2erg/cm(2) and sigma(e) = 69erg/cm(2), respectively. The work of chain folding is determined to be q = 33.75kJ/mol. Modified Avrami equation and Ozawa equation can be used to describe the non-isothermal crystallization behavior. And a new and convenient approach by combining the Avrami equation and Ozawa equation in a same crystallinity is used to describe the non-isothermal behavior as well. The crystallization activation energies are evaluated to be 73.7kJ/mol and 73.1kJ/mol for isothermal crystallization and non-isothermal crystallization, respectively. The Avrami exponent n is 1.5 similar to 1.6 for isothermal crystallization procedure, while the Avrami exponent n,is 2.5 similar to 3.5 for non-isothermal crystallization procedure. This indicated the difference of nucleation and growth between the two procedures.

Synthesis and properties of two series of H-bonded and non-H-bonded thermotropic liquid crystal monomers

Two series of monomers, namely n-1-bromo-(4-(4-nitrophenylazo)phenyloxy]alkanes (Bn, n = 2, 3, 4, 5, 6, 8, 10) and N-n-[4-(4-nitrophenylazo)phenyloxy]alkyl diethanolamines (Cn, n = 3, 5, 6, 10), were synthesized and characterized. Their thermal behaviour was studied by differential scanning calorimetry (DSC), wide angle X-ray diffractometry (WAXD) and polarizing optical microscopy (POM) equipped with a hot stage. The results showed that the Bns (n greater than or equal to 6) exhibit monotropic nematic liquid crystalline behaviour; no liquid crystalline phase was found for the Bns (n < 6), while for the Cns, enantiotropic smectic liquid crystallinity for n = 5, 6, 10 was seen, and for n = 3 monotropic smectic phases were found. This different phase behaviour between Bn and Cn compounds is attributed to their different end groups. The FTIR analysis of Cn indicated that there exists an intermolecular hydrogen bond between hydroxy groups, so that more stable liquid crystalline phase are formed. The effect of the length of the flexible chain on the thermal behaviour is also discussed.

Molecular cloning and expression of a Toll receptor gene homologue from Zhikong Scallop, Chlamys farreri

Toll-like receptors (TLRs) are an ancient family of pattern recognition receptors, which show homology with the Drosophila Toll protein and play key roles in detecting various non-self substances and then initiating and activating immune system. In this report, the full length of the first bivalve TLR (named as CfToll-1) is presented. CfToll-1 was originally identified as an EST (expressed sequence tag) fragment from a cDNA library of Zhikong scallop (Chlamys farreri). Its complete sequence was obtained by the construction of Genome Walker library and 5' RACE (rapid amplification of cDNA end) techniques. The full length cDNA of CfToll-1 consisted of 4308 nucleotides with a polyA tail, encoding a putative protein of 1198 amino acids with a 5' UTR (untranslated region) of 211 bp and a 3'UTR of 500 bp. The predicted amino acid sequence comprised an extracellular domain with a potential signal peptide, nineteen leucine-rich repeats (LRR), two LRR-C-terminal (LRRCT) motifs, and a LRR-N-terminal (LRRNT), followed by a transmembrane segment of 20 amino acids, and a cytoplasmic region of 138 amino acids containing the Toll/IL-1R domain (TIR). The deduced amino acid sequence of CfToll-1 was homologous to Drosophila melanogaster Tolls (DmTolls) with 23-35% similarity in the full length amino acids sequence and 30-54% in the TIR domain. Phylogenetic analysis of CfToll-1 with other known TLRs revealed that CfToll-1 was closely related to DmTolls. An analysis of the tissue-specific expression of the CfToll-1 gene by Real-time PCR showed that the transcripts were constitutively expressed in tissues of haemocyte, muscle, mantle, heart, gonad and gill. The temporal expressions of CfToll-1 in the mixed primary cultured haemocytes were observed after the haemocytes were treated with 1 mu g ml(-1) and 100 ng ml(-1) lipopolysaccharide (LPS), respectively. The expression of CfToll-1 was up-regulated and increased about 2-fold at 6 h with the treatment of 1 mu g ml(-1) LPS. The expression of CfToll-1 was down-regulated with the treatment of 100 ng ml(-1) LPS. The results indicated that the expression of CfToll-1 could be regulated by LPS, and this regulation was dose-dependent. (c) 2006 Elsevier Ltd. All rights reserved.

The complete mitochondrial genome of the mantid shrimp Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda): Novel non-coding regions features and phylogenetic implications of the Stomatopoda

The complete mitochondrial (mt) genome sequence of Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda) was determined; a circular molecule of 15,783 bp in length. The gene content and arrangement are consistent with the pancrustacean ground pattern. The mt control region of O. oratoria is characterized by no GA-block near the 3' end and different position of [TA(A)]n-blocks compared with other reported Stomatopoda species. The sequence of the second hairpin structure is relative conserved which suggests this region may be a synapomorphic character for the Stomatopoda. In addition, a relative large intergenic spacer (101 bp) with higher A + T content than that in control region was identified between the tRNA(Glu) and tRNA(Phe) genes. Phylogenetic analyses based on the current dataset of complete mt genomes strongly support the Stomatopoda is closely related to Euphausiacea. They in turn cluster with Penaeoidea and Caridea clades while other decapods form a separate group, which rejects the monophyly of Decapoda. This challenges the suitability of Stomatopoda as an outgroup of Decapoda in phylogenetic analyses. The basal position of Stomatopoda within Eumalacostraca according to the morphological characters is also questioned. (C) 2010 Elsevier Inc. All rights reserved.