Laut?u?erungen der Sommergoldh?hnchen von den Inseln Madeira und Mallorca (Regulus ignicapillus madeirensis, R. i. balearicus)

Zusammenfassung Von den Inselpopulationen des Sommergoldhähnchens auf den Balearen (Mallorca),Regulus ignicapillus balearicus, und auf Madeira,R. i. madeirensis, wird die Struktur des Reviergesanges und der Rufe dargestellt. Ssp.madeirensis weicht in beiden markant von denen der Nominatform ab, ssp.balearicus nur im Strophenaufbau geringfügig. Die intra-und interindividuelle Variabilität der Strophentypen ist bei ssp.balearicus höher als auf dem Festland. Am Strophenende treten häufig Elementgruppen auf, die in Mitteleuropa fehlen. Seltene Elementtypen der Nominatform (ssp.ignicapillus) finden sich bei ssp.balearicus gehäuft, ähnlich wie bei ssp.laeneni (Nordafrika). Drift-Effekte gelten als Ursachen für die Unterschiede zwischen Balearen/N-Afrika und Mitteleuropa. Jedes von ssp.madeirensis benutzt nur einen Strophentyp; er variiert interindividuell stark. Die Strophe ist dreiphrasig und wird von modifizierten Kampf- und Erregungsrufen dominiert. Die Erregungsrufe sind stark frequenzmoduliert und weisen Obertöne auf, die in der Gesangsstrophe fehlen können. Wahrscheinlich sind die Erregungsrufe dem Weia-Element aus dem Subsong von ssp.ignicapillus homolog. Der hohe Anteil angeborener Rufe immadeirensis-Reviergesang wird mit Lernentzug der Erstsiedler begründet. Attrappenversuche belegen die markanten akustischen Differenzen zwischen Sommergoldhähnchen von Madeira und Mitteleuropa. Reviergesang und Erregungsrufe vonR. i. madeirensis werden von der Nominatform ssp.ignicapillus in Mitteleuropa nicht als artspezifisch erkannt. Die Madeira-Goldhähnchen reagieren hingegen auf mittel- und südosteuropäische Strophentypen (ssp.ignicapillus undcaucasicus) stark territorial.

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Vocalisations of Firecrests from the islands of Madeira and Mallorca (Regulus ignicapillus madeirensis, R. i. balearicus)

Summary The vocal repertoire of two island populations of the Firecrest (R. ignicapillus) was studied. The song structure ofR. i. balearicus from Mallorca does not differ from that of nominateignicapillus, although intra- and interindividual variation of song types in Mallorca is higher than within continental populations, i.e. individual males use higher numbers of song types than nominateignicapillus in Central Europe. Several song types are terminated by distinct element groups strongly resembling song structures of North AfricanR. i. laeneni. The fixation of relatively rare element types and song patterns compared to Central EuropeanR. i. ignicapillus is explained by drift effects. The song repertoire of the individualR. i. madeirensis male is reduced to only one song type. This is divided into three phrases, two of them consisting of modified display and rage calls. While those song elements resemble innate calls, the reduction of learning opportunities which went along with the colonisation of Madeira is thought to be the main cause for the evolution of the Madeiran song type. Display calls are used in territorial contexts and differ greatly from those of other Firecrest subspecies in covering a larger frequency range and in including additional harmonics. Display calls are suspected to be a homologon of the excitement calls of nominateignicapillus, the weija note, which is also produced in subsong. Field experiments corroborate the evidence of a wide gap betweenR. i. madeirensis and nominateignicapillus song. Song and calls ofR. i. madeirensis do not evoke a notable territorial reaction in Central EuropeanR. i. ignicapillus, while the Madeiran Firecrests show strong reaction to the playback of Central and South-East European song types (ssp.ignicapillus andcaucasicus). Consequently,R. i. madeirensis is the only population of the Firecrest studied so far which differs considerably with respect to vocalisations from all four subspecies ofR. ignicapillus.

     

HSV and glycoprotein J inhibit caspase activation and apoptosis induced by granzyme B or Fas

HSV-1 inhibits apoptosis of infected cells, presumably to ensure that the infected cell survives long enough to allow completion of viral replication. Because cytotoxic lymphocytes kill their targets via the induction of apoptosis, protection from apoptosis could constitute a mechanism of immune evasion for HSV. Several HSV genes are involved in the inhibition of apoptosis, including Us5, which encodes glycoprotein J (gJ). Viruses deleted for Us5 showed defects in inhibition of caspase activation after Fas ligation or UV irradiation. Transfected cells expressing the Us5 gene product gJ were protected from Fas- or UV-induced apoptosis, as measured by morphology, caspase activation, membrane permeability changes, or mitochondrial transmembrane potential. In contrast, caspase 3 activation in mitochondria-free cell lysates by granzyme (gr)B was inhibited equivalently by Us5 deletion and rescue viruses, suggesting that gJ is not required for HSV to inhibition this process. However, mitochondria-free lysates from transfected cells expressing Us5/gJ were protected from grB-induced caspase activation, suggesting that Us5/gJ is sufficient to inhibit this process. Transfected cells expressing Us5/gJ were also protected from death induced by incubation with purified grB and perforin. These findings suggest that HSV has a comprehensive set of immune evasion functions that antagonize both Fas ligand- and grB-mediated pathways of CTL-induced apoptosis. The understanding of HSV effects on killing by CTL effector mechanisms may shed light on the incomplete control of HSV infections by the immune system and may allow more rational approaches to the development of immune modulatory treatments for HSV infection.     

New shuttle vectors for ectopic insertion of genes into Bacillus subtilis

We have constructed shuttle vectors for integration of genes via double homologous recombination into three ectopic sites on the chromosome of Bacillus subtilis. The sites of integration are the pyrD, gltA, and sacA genes located at 139 degrees, 172 degrees, and 333 degrees, respectively, on the chromosome. Integration of the vectors into the target genes leads to antibiotic resistance as well as different metabolic phenotypes. B. subtilis strains with integrations of the empty vectors were able to sporulate at rates comparable to wild type cells. Similar levels of expression were obtained from constitutive lacZ fusions integrated at the different sites.     

Combined prime-boost vaccination against tick-borne encephalitis (TBE) using a recombinant vaccinia virus and a bacterial plasmid both expressing TBE virus non-structural NS1 protein

Background  

Heterologous prime-boost immunization protocols using different gene expression systems have proven to be successful tools in protecting against various diseases in experimental animal models. The main reason for using this approach is to exploit the ability of expression cassettes to prime or boost the immune system in different ways during vaccination procedures. The purpose of the project was to study the ability of recombinant vaccinia virus (VV) and bacterial plasmid, both carrying the NS1 gene from tick-borne encephalitis (TBE) virus under the control of different promoters, to protect mice against lethal challenge using a heterologous prime-boost vaccination protocol.     

Identification of essential regions in the cytoplasmic tail of interleukin-1 receptor accessory protein critical for interleukin-1 signaling

Interleukin (IL)-1 plays an important role in inflammation and regulation of immune responses. The activated IL-1 receptor complex, which consists of the IL-1 receptor type I and the IL-1 receptor accessory protein (IL-1RAcP), generates multiple cellular responses including NF-kappaB activation, IL-2 secretion, and IL-2 promoter activation. Reconstitution experiments in EL4D6/76 cells lacking IL-1RAcP expression and IL-1 responsiveness were used to analyze structure-function relationships of the IL-1RAcP cytoplasmic tail. Mutating a potential tyrosine kinase phosphorylation motif and various conserved amino acid (aa) residues had no effect on IL-1 responsiveness. Truncation analyses revealed that box 3 of the TIR domain was required for NF-kappaB activation, IL-2 production, and c-Jun N-terminal kinase (JNK) activation, whereas IL-2 promoter activation was only partially inhibited. Surprisingly, deletion of aa 527-534 resulted in almost complete loss of all IL-1 responsiveness. Replacement of these aa with alanyl residues did not reconstitute NF-kappaB activation, IL-2 production, or JNK activation but partly restored IL-2 promoter activation. Immunoprecipitation data revealed a strong correlation between MyD88 binding with NF-kappaB activation and IL-2 production but not with IL-2 promoter activation. Taken together, our data indicate that box 3 of IL-1RAcP is critical for IL-1-dependent NF-kappaB activation and stabilization of IL-2 mRNA via JNK, whereas aa 527-534 largely contribute to IL-2 promoter activation.     

SEGMENTATION APPROACHES THAT DIFFERENTIATE CONSUMPTION FREQUENCY FROM SENSORY PREFERENCE1

People can eat a food without having a strong preference for it, and people can prefer a food without eating it. Given this seeming disconnect between attitude and behavior, which type of measure or segment can best be used to profile or identify loyal consumer segments of a food, such as soy? This research compares a usage‐based method (heavy‐light‐nonusers) with a new attitude‐based method (seeker‐neutral‐avoider), and finds that the attitude‐based method differentiates purchase‐related intentions better than the usage‐based method. Implications for profiling consumer taste patterns and consumer segments are provided.     

Characterization and molecular genetic complementation of mutants affecting dimorphism in the fungus ustilago maydis

Ustilago maydis, the causal agent of corn smut disease, displays dimorphic growth in which it alternates between a unicellular, nonpathogenic yeast-like form and a dikaryotic, pathogenic filamentous form. Previously, a constitutively filamentous haploid mutant was obtained. Complementation of this mutant led to the isolation of the gene encoding adenylate cyclase, uac1. Secondary mutagenesis of a uac1 disruption strain allowed the isolation of a large number of suppressor mutants, termed ubc, for Ustilago bypass of cyclase, lacking the filamentous phenotype. Analysis of one of these suppressor mutants previously led to the identification of the ubc1 gene, encoding the regulatory subunit of cAMP-dependent protein kinase. In this report we describe the isolation of cosmids containing three new ubc genes, termed ubc2, ubc3, and ubc4. We also describe the morphology of the ubc2, ubc3, and ubc4 mutants in a uac1- background as well as in a background with a functional uac1 gene. In addition, we describe several mutant strains not complemented with any of the genes currently in hand and that are thus presumed to possess mutations in additional ubc genes. Copyright 1998 Academic Press.     

Body size effects and rates of cytochrome b evolution in tube-nosed seabirds

Variation in rates of molecular evolution now appears to be widespread. The demonstration that body size is correlated with rates of molecular evolution suggests that physiological and ecological factors may be involved in molecular rate variation, but large-scale comparative studies are still lacking. Here, we use complete cytochrome b sequences from 85 species of tube-nosed seabirds (order Procellariiformes) and 5 outgroup species of penguins (order Sphenisciformes) to test for an association between body mass and rates of molecular evolution within the former avian order. Cladistic analysis of the 90 sequences estimates a phylogeny largely consistent with the traditional taxonomy of the Procellariiformes. The Diomedeidae, Procellariidae, and Pelecanoididae are monophyletic, while the Hydrobatidae are basal and paraphyletic. However, the two subfamilies within the Hydrobatidae (Hydrobatinae and Oceanitinae) are monophyletic. A likelihood ratio test detects significant deviation from clocklike evolution in our data. Using a sign test for an association between body mass and branch length in the seabird phylogeny, we find that larger taxa tend to have shorter terminal branch lengths than smaller taxa. This observation suggests that rates of mitochondrial DNA evolution are slower for larger taxa. Rate calibrations based on the fossil record reveal concordant body size effects. We interpret these results as evidence for a metabolic rate effect, as the species in this order exhibit large differences in metabolic rates, which are known to be highly correlated with body mass in this group. Our results support previous findings of body size effects and show that this effect can be significant even within a single avian order. This suggests that even lineage-specific molecular clocks may not be tenable if calibrations involve taxa with different metabolic rates.      

Molecular evolution of chloroplast DNA sequences

Comparative data on the evolution of chloroplast genes are reviewed. The chloroplast genome has maintained a similar structural organization over most plant taxa so far examined. Comparisons of nucleotide sequence divergence among chloroplast genes reveals marked similarity across the plant kingdom and beyond to the cyanobacteria (blue-green algae). Estimates of rates of nucleotide substitution indicate a synonymous rate of 1.1 x 10(-9) substitutions per site per year. Noncoding regions also appear to be constrained in their evolution, although addition/deletion events are common. There have also been evolutionary changes in the distribution of introns in chloroplast encoded genes. Relative to mammalian mitochondrial DNA, the chloroplast genome evolves at a conservative rate.