Newly discovered insect RNA viruses in China

Insects are a group of arthropods and the largest group of animals on Earth,with over one million species described to date.Like other life forms,insects suffer from viruses that cause disease and death.Viruses that are pathogenic to beneficial insects cause dramatic economic losses on agriculture.In contrast,viruses that are pathogenic to insect pests can be exploited as attractive biological control agents.All of these factors have led to an explosion in the amount of research into insect viruses in recent years,generating impressive quantities of information on the molecular and cellular biology of these viruses.Due to the wide variety of insect viruses,a better understanding of these viruses will expand our overall knowledge of their virology.Here,we review studies of several newly discovered RNA insect viruses in China.     

Newly discovered young CORE-SINEs in marsupial genomes

Although recent mammalian genome projects have uncovered a large part of genomic component of various groups, several repetitive sequences still remain to be characterized and classified for particular groups. The short interspersed repetitive elements (SINEs) distributed among marsupial genomes are one example. We have identified and characterized two new SINEs from marsupial genomes that belong to the CORE-SINE family, characterized by a highly conserved "CORE" domain. PCR and genomic dot blot analyses revealed that the distribution of each SINE shows distinct patterns among the marsupial genomes, implying different timing of their retroposition during the evolution of marsupials. The members of Mar3 (Marsupialia 3) SINE are distributed throughout the genomes of all marsupials, whereas the Mac1 (Macropodoidea 1) SINE is distributed specifically in the genomes of kangaroos. Sequence alignment of the Mar3 SINEs revealed that they can be further divided into four subgroups, each of which has diagnostic nucleotides. The insertion patterns of each SINE at particular genomic loci, together with the distribution patterns of each SINE, suggest that the Mar3 SINEs have intensively amplified after the radiation of diprotodontians, whereas the Mac1 SINE has amplified only slightly after the divergence of hypsiprimnodons from other macropods. By compiling the information of CORE-SINEs characterized to date, we propose a comprehensive picture of how SINE evolution occurred in the genomes of marsupials.     

Newly discovered orally active pure antiestrogens

In order to develop orally active pure antiestrogens, we incorporated the carboxy-containing side chains into the 7alpha-position of the steroid scaffold and found that 17-keto derivative CH4893237 (12b) functioned as a pure antiestrogen with its oral activity much superior to clinically used pure antiestrogen, ICI182,780. Results from the pharmacokinetic evaluation indicated that the potent antiestrogen activity at oral dosing in mice attributed to both improved absorption from the intestinal wall and metabolic stability in liver.     

Newly discovered functions for some myotropic neuropeptides in locusts

The field of neuropeptide research in insects during the past twenty years can be characterized by the enormous number of peptides that have been identified. In the locusts, Locusta migratoria and Schistocerca gregaria only, structural information is now available for more than 60 peptides. Quite a number of these peptides were isolated on the basis of their effect on visceral muscle contraction in vitro. A very limited number of reports describe the 'in vivo' function of a myotropic neuropeptide. Moreover, for most of the brain neuropeptides, we ignore whether they have a hormonal function. In this paper, we describe the recently discovered in vivo effects of some of the myotropic peptides, identified in locusts in the past decade. Schistocerca-neuropeptide F accelerates egg development; locustasulfakinin inhibits food intake and [His(7)]-corazonin induces body color pigmentation.     

Newly discovered polyamine, 2-hydroxyspermidine, in Pseudomonas acidovorans.

A previously unknown hydroxylated polyamine has been recovered from Pseudomonas acidovorans 29. It has been identified as 2-hydroxyspermidine, N4-(3-aminopropyl)-1,4-diaminobutane-2-ol, by its chromatographic behavior, electrophoretic mobility, and reaction with metaperiodate. It can be synthesized enzymatically from 2-hydroxyputrescine by cell-free preparations from Escherichia coli or P. acidovorans 29 which contain propylamine transferase. It is interesting to note that the naturally occurring compound is the 2-hydroxyspermidine and not the 3-hydroxyspermidine, N1-(3-aminopropyl)-1,4-diaminobutane-2-ol, indicating that the propylamine transferase reacts preferentially with the amine distal to the hydroxyl group. A mixture of 2- and 3-hydroxyspermidines and hydroxyspermine was synthesized by reacting acrylonitrile with 2-hydroxyspermidine and catalytic reduction of the products with hydrogen. N-(gamma-aminopropyl)-beta-alanine, used to help identify the hydroxyspermidines, was synthesized from N-(3-aminopropyl)-3-aminopropanenitrile by hydrolysis with 10% NaOH.     

Tethering of proteins to RNAs by bacteriophage proteins

Many steps in the control of gene expression are dependent on RNA-binding proteins, most of which are bi-functional, in as much as they both bind to RNA and interact with other protein partners in a functional complex. A powerful approach to study the functional properties of these proteins in vivo, independently of their RNA-binding ability, is to attach or tether them to specifically engineered reporter mRNAs whose fate can be easily followed. Two tethering systems have been mainly used in eukaryotic cells, namely the MS2 coat protein system and the lambda N-B box system. In this review, we firstly describe several studies in which these tethering systems have been used and provide an overview of these applications. We next describe the major features of these two systems, and, finally, we highlight a number of points that should be considered when designing experiments using this approach.     

Tethering of proteins to RNAs by bacteriophage proteins.

Many steps in the control of gene expression are dependent on RNA-binding proteins, most of which are bi-functional, in as much as they both bind to RNA and interact with other protein partners in a functional complex. A powerful approach to study the functional properties of these proteins in vivo, independently of their RNA-binding ability, is to attach or tether them to specifically engineered reporter mRNAs whose fate can be easily followed. Two tethering systems have been mainly used in eukaryotic cells, namely the MS2 coat protein system and the lambda N-B box system. In this review, we firstly describe several studies in which these tethering systems have been used and provide an overview of these applications. We next describe the major features of these two systems, and, finally, we highlight a number of points that should be considered when designing experiments using this approach.     

Not just a sponge: new functions of circular RNAs discovered

<正>One of the most exciting findings in RNA biology is the discovery of numerous circular RNAs(circ RNA)in mammalian genome.Once being considered as low abundance splicing byproducts,circ RNAs are surprisingly abundant     

Cloning of genes for bacteriophage T5 stable RNAs

One EcoRI-generated fragment (440 basepairs) and two EcoRI/HindIII fragments (220 and 960 basepairs) from the deletion region of T5 phage have been inserted into the phage λ XIII and the plasmid pBR322 as vectors. Recombinant DNA molecules were studied by hybridization with in vivo ³²P-labeled T5 4–5 S RNAs on nitrocellulose filters. Two-dimensional polyacrylamide gel electrophoretic fractionation and fingerprint analysis of the RNAs eluted from the filters were carried out to identify RNAs coded by cloned fragments. For the accurate localization of the genes for these RNAs, RNA-DNA hybrids were treated with T1 and pancreatic RNAases, and the eluted RNA fragments stable against RNAase action were electrophoresed. It was shown that the EcoRI¹440 fragment contains the gene for tRNA 10 (tRNA^Asp), the EcoRI/HindIII¹220 fragment contains the gene for RNA III (107 bases) and parts of the genes for RNA I (107 bases) and tRNA 12 (tRNA^His), and the EcoRI/HindIII¹960 fragment contains only a part of the gene for tRNA 9 (tRNA^Gln). The arrangement of these genes on the physical map of T5 phage was as follows: -tRNA^Gln-tRNA^His-RNA III-RNA I-…-tRNA^Asp.     

SRSF3: Newly discovered functions and roles in human health and diseases

The serine/arginine rich proteins (SR proteins) are members of a family of RNA binding proteins involved in regulating various features of RNA metabolism, including pre-mRNA constitutive and alternative splicing. In humans, a total of 12 SR splicing factors (SRSFs) namely SRSF1-SRSF12 have been reported. SRSF3, the smallest member of the SR family and the focus of this review, regulates critical steps in mRNA metabolism and has been shown to have mRNA-independent functions as well. Recent studies on SRSF3 have uncovered its role in a wide array of complex biological processes. We have also reviewed the involvement of SRSF3 in disease conditions like cancer, ageing, neurological and cardiac disorders. Finally, we have discussed in detail the autoregulation of SRSF3 and its implications in cancer and commented on the potential of SRSF3 as a therapeutic target, especially in the context of cancer.     

Newly discovered reproductive isolation reveals sympatric populations of Esox Indus in the Baltic

Two populations of pike Esox lucius have been identified on the eastern coast of Sweden, in the Baltic Sea. These live together, but separate into two different populations during the spawning season. One is an obligate freshwater spawner and the other not only reproduces in ambient Baltic salinities, but appears not to enter fresh water at all.     

Studies on the bacteriophage MS2: XXXIII. Comparison of the nucleotide sequences in related bacteriophage RNAs

We have recently determined the complete nucleotide sequence of the MS2 bacteriophage RNA molecule (Min Jou et al., 1972; Fiers et al., 1975,1976). Extensive segments of the sequence of the closely related phages R17 (23.9%) and f2 (11.5%) have been studied in other laboratories (Table 1). A comparison between the sequences of the phages MS2, R17 and f2 can now be given a functional significance by referring to the complete MS2 RNA sequence (Fig. 1).The estimation of the over-all degree of variation amounts to 3.9% (MS2-R17), 3.4% (MS2-f2) and 3.7% (R17-f2). All the differences observed can be accounted for by single base substitutions: transitions are highly predominant (86%). No change is found in the untranslated terminal regions and only two mutations occur in the intercistronic regions. From a total of 34 observed variable sites located in translated regions, 25 are neutral point mutations and only 9 lead to an (mostly rather conservative) amino acid change. The amount of variation in double-stranded regions (16 out of 36 cases) is much lower than the relative degree of secondary structure of the RNA (roughly two-thirds) would predict. Hence, there is clearly a selective pressure to preserve at least certain aspects of the three-dimensional conformation.     

Newly discovered mechanisms that mediate tumorigenesis and tumour progression: circRNA-encoded proteins

Proteins produced by cap-independent translation mediated by an internal ribosome entry site (IRES) in circular RNAs (circRNAs) play important roles in tumour progression. To date, numerous studies have been performed on circRNAs and the proteins they encode. In this review, we summarize the biogenesis of circRNAs and the mechanisms regulating circRNA-encoded proteins expression. We also describe relevant research methods and their applications to biological processes such as tumour cell proliferation, metastasis, epithelial-mesenchymal transition (EMT), apoptosis, autophagy and chemoresistance. This paper offers deeper insights into the roles that circRNA-encoded proteins play in tumours. It also provides a theoretical basis for the use of circRNA-encoded proteins as biomarkers of tumorigenesis and for the development of new targets for tumour therapy.     

Newly discovered penicillin acylase activity of aculeacin A acylase from Actinoplanes utahensis

Aculeacin A acylase from Actinoplanes utahensis produced by Streptomyces lividans revealed acylase activities that are able to hydrolyze penicillin V and several natural aliphatic penicillins. Penicillin K was the best substrate, showing a catalytic efficiency of 34.79 mM(-1) s(-1). Furthermore, aculeacin A acylase was highly thermostable, with a midpoint transition temperature of 81.5 degrees C.     

Newly discovered linkages between the cortical (pellicular) ridges of Opalina

Samples of Opalina ranarum have been prepared for electron microscopy by ultra-rapid cryofixation followed by substitution fixation in a solvent containing tannic acid. This technique has made it possible to see that very thin linkages exist between the pleated ridges that form the surface of the cell. Between any two adjacent cortical ridges, the linkages, which are approximately 0.1 μm long, occur as a single row, 0.1 μm below the free edge, with an impressively regular spacing of 0.1 μm. The cortical ridges of the Opalinids are spaced with remarkable uniformity, even when thrown into undulating patterns. The linkages described here will inevitably stabilize the complex architecture of the cortex. Other possible functions are discussed.     

东秦岭卢氏盆地新发现的旧石器

2019年6-8月,在秦岭东部南洛河流域河南卢氏盆地开展古人类和旧石器考古遗址调查,在南洛河不同阶地之上的黄土堆积地层中新发现旧石器地点27处,采集石制品123件。部分石制品采自于阶地顶部暴露的黄土地层剖面上。石制品包括石核、石片、断块、碎屑、石器等类型,整体属于简单的石核-石片工业。原料为取自河滩砾石堆积的石英、砂岩和石英岩等。石核为简单剥片的单台面石核和转向剥片石核。石器组合中既有手镐、砍砸器等重型类型,也有以石片为毛坯的中小型刮削器等。根据黄土-古土壤地层序列初步判断,多数地点的石制品出自黄土L1-S2地层堆积,年代范围涵盖中更新世晚期至晚更新世;西庄村南（19LS35）和九寨山（19LS27）两个地点的2件石制品则出自更早的S9和S13古土壤地层堆积中,它们的发现为进一步探寻南洛河流域最早的古人类活动提供了关键性的考古学证据。本次调查扩大了卢氏盆地旧石器时代遗存的时空分布范围,为本区域旧石器遗址的保护和制订研究计划提供了更为全面的依据。