To the knowledge of the fauna of Microlepidoptera of the “Kurshskaya Kosa” National Park: I

A list of 212 Microlepidoptera species found in the territory of the Curonian Spit (both in its Russian and Lithuanian parts) is given: Micropterigidae (1), Eriocraniidae (1), Nepticulidae (16), Opostegidae (1), Heliozelidae (1), Adelidae (3), Prodoxidae (2), Incurvariidae (2), Tineidae (8), Psychidae (1), Douglasiidae (2), Bucculatricidae (3), Gracillariidae (26), Yponomeutidae (12), Plutellidae (3), Acrolepiidae (2), Glyphipterigidae (3), Lyonetiidae (1), Ethmiidae (1), Depressariidae (12), Elachistidae (20), Chimabachidae (1), Oecophoridae (9), Stathmopodidae (1), Batrachedridae (2), Coleophoridae (25), Momphidae (3), Blastobasidae (2), Cosmopterigidae (3), Choreutidae (1), Schreckensteiniidae (1), Epermeniidae (1), Alucitidae (1), Pterophoridae (7) and Pyralidae (35 species). 113 species of 24 families have been collected in the territory of the “Kurshskaya Kosa” National Park, including 45 species new to the Curonian Spit and 32 species new to Kaliningrad Province.     

Properties of the competence-inducing factor of Bacillus subtilis 168I−

It has been shown that the competence-inducing factor of Bacillus subtilis 168I^? exhibits lytic activity toward isolated cell walls and nuclease activity toward transforming DNA. It has been shown that the competence factor covalently bound to CNBr-Sepharose exhibits the same enzymatic properties. A mechanism for the transformation process is proposed which advances the mechanism previously proposed by this laboratory.     

Alternative splicing of the neurofibromatosis type I pre-mRNA

NF1 (neurofibromatosis type?I) is a common genetic disease that affects one in 3500 individuals. The disease is completely penetrant but shows variable phenotypic expression in patients. NF1 is a large gene, and its pre-mRNA undergoes alternative splicing. The NF1 protein, neurofibromin, is involved in diverse signalling cascades. One of the best characterized functions of NF1 is its function as a Ras-GAP (GTPase-activating protein). NF1 exon 23a is an alternative exon that lies within the GAP-related domain of neurofibromin. This exon is predominantly included in most tissues, and it is skipped in CNS (central nervous system) neurons. The isoform in which exon 23a is skipped has 10?times higher Ras-GAP activity than the isoform in which exon 23a is included. Exon 23a inclusion is tightly regulated by at least three different families of RNA-binding proteins: CELF {CUG-BP (cytosine-uridine-guanine-binding protein) and ETR-3 [ELAV (embryonic lethal abnormal vision)-type RNA-binding protein]-like factor}, Hu and TIA-1 (T-cell intracellular antigen 1)/TIAR (T-cell intracellular antigen 1-related protein). The CELF and Hu proteins promote exon 23a skipping, while the TIA-1/TIAR proteins promote its inclusion. The widespread clinical variability that is observed among NF1 patients cannot be explained by NF1 mutations alone and it is believed that modifier genes may have a role in the variability. We suggest that the regulation of alternative splicing may act as a modifier to contribute to the variable expression in NF1 patients.     

Contributions to the mathematical theory of epidemics—I

(1) A mathematical investigation has been made of the progress of an epidemic in a homogeneous population. It has been assumed that complete immunity is conferred by a single attack, and that an individual is not infective at the moment at which he receives infection. With these reservations the problem has been investigated in its most general aspects, and the following conclusions have been arrived at. (2) In general a threshold density of population is found to exist, which depends upon the infectivity, recovery and death rates peculiar to the epidemic. No epidemic can occur if the population density is below this threshold value. (3) Small increases of the infectivity rate may lead to large epidemics; also, if the population density slightly exceeds its threshold value the effect of an epidemic will be to reduce the density as far below the threshold value as initially it was above it. (4) An epidemic, in general, comes to an end, before the susceptible population has been exhausted. (5) Similar results are indicated for the case in which transmission is through an intermediate host.     

Heavy chains of inter alpha inhibitor (IαI) inhibit the human complement system at early stages of the cascade

Inter alpha inhibitor (IαI) is an abundant serum protein consisting of three polypeptides: two heavy chains (HC1 and HC2) and bikunin, a broad-specificity Kunitz-type proteinase inhibitor. The complex is covalently held together by chondroitin sulfate but during inflammation IαI may interact with TNF-stimulated gene 6 protein (TSG-6), which supports transesterification of heavy chains to hyaluronan. Recently, IαI was shown to inhibit mouse complement in vivo and to protect from complement-mediated lung injury but the mechanism of such activity was not elucidated. Using human serum depleted from IαI, we found that IαI is not an essential human complement inhibitor as was reported for mice and that such serum has unaltered hemolytic activity. However, purified human IαI inhibited classical, lectin and alternative complement pathways in vitro when added in excess to human serum. The inhibitory activity was dependent on heavy chains but not bikunin and detected at the level of initiating molecules (MBL, properdin) in the lectin/alternative pathways or C4b in the classical pathway. Furthermore, IαI affected formation and assembly of the C1 complex and prevented assembly of the classical pathway C3-convertase. Presence and putative interactions with TSG-6 did not affect the ability of IαI to inhibit complement thus implicating IαI as a potentially important complement inhibitor once enriched onto hyaluronan moieties in the course of local inflammatory processes. In support of this, we found a correlation between IαI/HC-containing proteins and hemolytic activity of synovial fluid from patients suffering from rheumatoid arthritis.     

Understanding the Role of Three-Dimensional Topology in Determining the?Folding Intermediates of Group I Introns

Many RNA molecules exert their biological function only after folding to unique three-dimensional structures. For long, noncoding RNA molecules, the complexity of finding the native topology can be a major impediment to correct folding to the biologically active structure. An RNA molecule may fold to a near-native structure but not be able to continue to the correct structure due to a topological barrier such as crossed strands or incorrectly stacked helices. Achieving the native conformation thus requires unfolding and refolding, resulting in a long-lived intermediate. We investigate the role of topology in the folding of two phylogenetically related catalytic group I introns, the Twort and Azoarcus group I ribozymes. The kinetic models describing the Mg²⁺-mediated folding of these ribozymes were previously determined by time-resolved hydroxyl (⋅OH) radical footprinting. Two intermediates formed by parallel intermediates were resolved for each RNA. These data and analytical ultracentrifugation compaction analyses are used herein to constrain coarse-grained models of these folding intermediates as we investigate the role of nonnative topology in dictating the lifetime of the intermediates. Starting from an ensemble of unfolded conformations, we folded the RNA molecules by progressively adding native constraints to subdomains of the RNA defined by the ⋅OH time-progress curves to simulate folding through the different kinetic pathways. We find that nonnative topologies (arrangement of helices) occur frequently in the folding simulations despite using only native constraints to drive the reaction, and that the initial conformation, rather than the folding pathway, is the major determinant of whether the RNA adopts nonnative topology during folding. From these analyses we conclude that biases in the initial conformation likely determine the relative flux through parallel RNA folding pathways.     

Folding kinetics of the cooperatively folded subdomain of the IκBα ankyrin repeat domain

The ankyrin repeat (AR) domain of IκBα consists of a cooperative folding unit of roughly four ARs (AR1-AR4) and of two weakly folded repeats (AR5 and AR6). The kinetic folding mechanism of the cooperative subdomain, IκBα_67-206, was analyzed using rapid mixing techniques. Despite its apparent architectural simplicity, IκBα_67-206 displays complex folding kinetics, with two sequential on-pathway high-energy intermediates. The effect of mutations to or away from the consensus sequences of ARs on folding behavior was analyzed, particularly the GXTPLHLA motif, which have not been examined in detail previously. Mutations toward the consensus generally resulted in an increase in folding stability, whereas mutations away from the consensus resulted in decreased overall stability. We determined the free energy change upon mutation for three sequential transition state ensembles along the folding route for 16 mutants. We show that folding initiates with the formation of the interface of the outer helices of AR3 and AR4, and then proceeds to consolidate structure in these repeats. Subsequently, AR1 and AR2 fold in a concerted way in a single kinetic step. We show that this mechanism is robust to the presence of AR5 and AR6 as they do not strongly affect the folding kinetics. Overall, the protein appears to fold on a rather smooth energy landscape, where the folding mechanism conforms a one-dimensional approximation. However, we note that the AR does not necessarily act as a single folding element.     

Characterization of the MHC class I region of the Japanese pufferfish (Fugu rubripes)

A BAC map of the Japanese pufferfish (Fugu) MHC class I region was constructed using a mixture of sequence scanning and sequence-tagged site mapping methodologies. The Fugu MHC class Ia genes are linked to genes which are found within the human classical MHC class II and extended class II regions, a situation which has been found in the MHC of all teleosts mapped so far. The 300-kb contig comprises 24 MHC-related genes and is bounded by six non-MHC genes, which are thought to represent an evolutionary breakpoint within the region. Comparative analysis with both human and zebrafish MHC maps indicates two blocks of genes (KNSL2, ZNF297, DAXX, TAPBP, FLOTILLIN; and PSMB8, PSMB10, PSMB9, ABCB3, FABGL, BRD2, COL11A2, RXRB) which have remained linked over 400 million years and may represent an ancestral arrangement of the vertebrate MHC. Zebrafish and Fugu diverged between 100-200 million years ago and differences exist between these two fish species. The position and number of MHC class Ia genes is not conserved between species, there is an inversion of a block of nine genes centering on the PSMB cluster, and additional genes are present in zebrafish coding for a transport-associated protein and a beta proteasome subunit. The extent of these differences has implications for the extrapolation of fish model organism data to commercial aquaculture species. The data presented here represent the most extensive analysis of a fish MHC class Ia region described so far and clearly delimit the extent of this region in Fugu and, potentially, all teleosts.     

Physical mapping and evolution of the centromeric class I gene-containing region of the rat MHC

We physically mapped the centromeric part of the BN rat MHC (RT1n haplotype) in a contig of overlapping P1-derived artificial chromosome (PAC) clones encompassing about 300 kb. The following genes were identified and ordered as: (Syngap, Hset, Daxx, Bing1)-Tapbp-Rgl2-Ke2-Bing4-B3galt4- Rps18-Sacm2l-RT1-A1-RT1-A2-RT1-A3-Ring1-Ring2-++ +Ke4-Rxrb-Col11a2-RT1-Hb-Ring3-RT1-DMb. Thus, in contrast to other RT1 haplotypes, RT1n contains three class I genes, RT1-A1, RT1-A2, and RT1-A3, mapping between the Sacm2l and Ring1 genes. Comparisons of the sequences flanking the Sacm2L and Ring1 genes in rat, human, and mouse suggest that the class I gene-containing region was inserted between these genes in rat and mouse at a similar position. Thus, this insertion is likely to have occurred in a common ancestor of these rodents, although the presence of a site particularly permissive for insertions cannot be excluded.     

Respiratory complex I: 'steam engine' of the cell?

Complex I is the first enzyme of the respiratory chain and plays a central role in cellular energy production. It has been implicated in many human neurodegenerative diseases, as well as in ageing. One of the biggest membrane protein complexes, it is an L-shaped assembly consisting of hydrophilic and membrane domains. Previously, we have determined structures of the hydrophilic domain in several redox states. Last year was marked by fascinating breakthroughs in the understanding of the complete structure. We described the architecture of the membrane domain and of the entire bacterial complex I. X-ray analysis of the larger mitochondrial enzyme has also been published. The core subunits of the bacterial and mitochondrial enzymes have remarkably similar structures. The proposed mechanism of coupling between electron transfer and proton translocation involves long-range conformational changes, coordinated in part by a long α-helix, akin to the coupling rod of a steam engine.     

Ultrastructure of meiosis in the hollyhock rust fungus,Puccinia malvacearum I. Prophase I — Prometaphase I

Summary A thoroughly documented account of the ultrastructure of the meiotic spindle pole body (SPB) cycle in a rust (Basidiomycota, Uredinales) is presented for the first time. The three-dimensional structure of the SPB and spindle during meiosis in the hollyhock rust fungusPuccinia malvacearum is analyzed from serial sections of preselected stages. This paper covers prophase I to prometaphase I. At late prophase I, the nucleolus disperses and does not reappear until the end of meiosis. The SPB at late prophase I consists of two, 4-layered discs, 0.8–1.0 m in diameter, connected by a middle piece (MP). The SPB is associated with a differentiated region of the nuclear envelope and nucleoplasm. At late diplotene to diakinesis, each disc generates a half spindle as it inserts into an otherwise intact nuclear envelope. The MP connecting the interdigitating half spindles elongates and eventually splits transversely during subsequent spindle elongation. Each half MP, which is attached to a SPB disc, becomes inserted in a sheath-like extension of the nuclear envelope. The intranuclear late prometaphase I spindle always becomes oriented perpendicularly to the longitudinal axis and sagittal plane of the metabasidium. There are 200–290 spindle microtubules (MTs) at each SPB at late prometaphase. The nonkinetochore MTs form a coherent central spindle around which the kinetochore MTs and bivalents are spread. A metaphase plate is absent. The results are compared with SPB behavior and spindle structure in early meiosis of other basidiomycetes and ascomycetes.     

Indication of the metarhodopsin I–II transition by absorption-changes of eriochromblack T

The dye eriochromblack T (erio T), added to an aqueous suspension of bovine retinal outer segments solubilized by digitonin, shows a light-induced absorption-increase at =645 nm. Erio T is shown to directly interact with micellar metarhodopsm I and metarhodopsin II. The absorption-changes of erio T can be regarded as an indication of the transition from the metarhodopsin I conformation (with associated Ca²⁺) to the metarhodopsin II conformation (with associated H⁺).Thanks are due to the Deutsche Forschungsgemeinschaft for financial support (Em 18/1-4).     

Genetic studies on the deficiency of ß2-glycoprotein I of human serum

Summary ₂-glycoprotein I concentrations have been determined in human sera by the radial immunodiffusion technique. In 260 healthy individuals a bimodal distribution was observed. In 94% of sera concentrations ranged from 16 to 30 mg/100 ml with a mean value of 21.3±3.6 mg/100 ml. In 6% of sera lower concentrations were found: x=10.0±1.3 per 100 ml. The results of a study of 38 families with 79 children suggest that ₂-glycoprotein I concentrations are controlled by a pair of autosomal co-dominant alleles called Bg^N and Bg^D. Individuals homozygous for the common allele Bg^N have levels between 16 and 30 mg/100 ml, heterozygous individuals have lower concentrations of 6 to 14 mg/100 ml. Individuals homozygous for the rate allele Bg^D have deficiency of ₂-glycoprotein I. The results in one family, however, did not conform to this simple genetic hypothesis. The concentration of ₂-glycoprotein I in serum is also influenced to some extent by non-genetic factors such as sex, age, and various pathologic conditions. The biological function of this glycoprotein is still unknown.Supported by a grant from the Deutsche Forschungsgemeinschaft, Bad Godesberg, and by U.S. PHS Grant AM 11796.