Beiträge zur Collembolenfauna von Höhlen der deutschen Mittelgebirge (Harz, Kyffhäuser, Thüringer Wald, Zittauer Gebirge) (Insecta: Collembola).

Im Verlaufe von vier Jahren (1988-1991) wurden in den deutschen Mittelgebirgen der Bundesländer Sachsen-Anhalt (Mittel- und Südharz), Thüringen (Kyffhäuser, Thüringer Wald) und Sachsen (Zittauer Gebirge) insgesamt 224 Höhlen und Stollen auf ihre terrestrische Arthropodenfauna untersucht. Neben den Aufsammlungen per Hand wurden in 168 Objekten über 400 Äthylenglykol-Bodenfallen für je ein Jahr aufgestellt und in dieser Zeit 3-5 mal geleert. Neben rund 40 000 anderen Arthropoden wurden 30 600 Collembolen gefangen. Diese verteilen sich auf 77 Arten aus zwölf Familien. - Neu für die deutsche Fauna sind 10 Arten: Arrhopalites boneti, A. terricola, Isotoma neglecta, I. proprinqua, Lepidocyrtus nigrescens, Neanura longiseta, Onychiurus heterodoxus, O. schoetti, Orchesella longifasciata, Paranura sexpunctata. 21 Arten wurden erstmals in Höhlen nachgewiesen: Dicyrtoma minuta, Entomobrya marginata, Folsomia manolachei, F. penicula, Hypogastrura burkilli, Isotoma neglecta, Lepidocyrtus nigrescens, Neanura conjuncta, Onychiurus absoloni, O. sublegans, O. heterodoxus, O. vanderdrifti, Orchesella flavescens, O. longifasciata, Paranura sexpunctata, Pseudachorutes asigillata, P. corticola, P. subcrassus, Sminthurinus niger, Willemia intermedia und Xenyllodes armatus. Am häufigsten vertreten waren Lepidocyrtus violaceus (5.645 Tiere/ 70 Höhlen) und Arrhopalites pygmaeus (5.137/72), gefolgt von Isotoma neglecta, Hypogastrura purpurescens, Tomocerus flavescens, Heteromurus nitidus, Onychiurus cebennarius und Lepidocyrtes curvicollis. - Der Aspekt der Höhlenbindung wird ausführlich diskutiert. 73 der 77 Arten sind zwar auch außerhalb und nur drei ausschließlich in Höhlen anzutreffen, allerdings bilden einige als trogloxen oder troglophil bekannte Arten auch stabile Höhlenpopulationen. Sie sind somit neben ihrer sonstigen trogloxenen oder troglophilen Lebensweise auch als sub- oder eutroglobiont einzustufen. - Mit Sicherheit eutroglobiont sind in den untersuchten Höhlen Arrhopalites pygmaeus, Heteromurus nitidus, Hypogastrura purpurescens, Megalothorax minimus, Onychiurus cebennarius, O. heterodoxus, Pseudosinelle alba und Schaefferia quadrioculata. Subtroglobiont sind die vier Arten I. neglecta, L. curvicollis, L. violaceus und T. minor. Sie bilden zwar auch stabile Höhlenpopulationen, haben aber kaum oder noch keine morphologischen Anpassungen an das Höhlenleben. - Nur in einzelnen Höhlen gefunden und/oder in geringer Individuenzahl nachgewiesen und darum nur als wahrscheinlich eutroglobiont bzw. wahrscheinlich subtroglobiont einzustufen sind F. candida, O. absoloni, O. armatus, O. sublegans und P. decipiens bzw. A. principalis, E. marginalis, I. tigrina, L. nigrescens, N. muscorum und T. vulgaris. - Nur vereinzelt in kleineren Höhlen nachweisen konnten wir fünf weitere, als vorwiegend in Höhlen lebend bekannte Arten: Mesogastrura ojcoviensis, Schaefferia decemoculata, Sch. emucronata, Sch. willemi, Arrhopalites boneti.StichwörterCollembola, Faunistics, Caves, Germany, Harz, Kyffhäuser, Thüringer Wald, Zittauer Gebirge.In four German highlands (Harz, Kyffhäuser, Thüringer Wald, and Zittauer Gebirge) the terrestical arthropod fauna of caves and adits was investigated over a period of 4 years. 224 out of about 250 caves and tunnels visited were selected and investigated quantitatively and qualitatively. Each object was controlled 3 to 5 times during a period of one year. The arthropods were either collected by hand or caught by pitfall traps filled with ethylene glycol. Depending on the size of the cave and adit, respectively, two to 20 of the traps were deposited in about 60% of the selected caves. The following 10 species are new for the fauna of Germany: Arrhopalites boneti, A. terricola, Isotoma neglecta, I. proprinqua, Lepidocyrtus nigrescens, Neanura longiseta, Onychiurus heterodoxus, O. schoetti, Orchesella longifasciatus, Paranura sexpunctata. - The following 21 species were found in caves for the first time: Dicyrtoma minuta, Entomobrya marginata, Folsomia manolachei, F. penicula, Hypogastrura burkilli, Isotoma neglecta, Lepidocyrtus nigrescens, Neanura conjuncta, Onychiurus absoloni, O. heterodoxus, O. vanderdrifti, Orchesella flavescens, O. longifasciata, Paranura sexpunctata, Pseudachorutes asigillatus, P. corticola, P. subcrassus, Sminthurinus niger, Willemia anophthalma, W. intermedia and Xenyllodes armatus. The most frequent species were as follows: Lepidocyrtus violaceus (5 645 specimens / 70 caves) and Arrhopalites pygmaeus (5 137/72), Isotoma neglecta (2 233/25), Hypogastrura purpurescens (2 135/28), Tomocerus flavescens (1 818/59); Heteromurus nitidus (1 708/50), Onychiurus cebennarius (1 660/25), and Lepidocyrtes curvicollis (1 162/31). - The range of adaptions to a life within caves are discussed in further detail below. 73 of the 77 species detected also occur outside caves, and only 3 species exclusively live in caves. Some of the species known as trogloxene or troglophilic, however, form permanent populations in caves. This means they can be trogloxene, troglophilic or troglobiont. - 8 species, namely Arrhopalites pygmaeus, Heteromurus nitidus, Hypogastrura purpurescens, Megalothorax minimus, Onychiurus cebennarius, O. heterodoxus, Pseudosinelle alba and Schaefferia quadrioculata have been identified as eutroglobiont in our caves. Four other species - I. neglecta, L. curvicollis, L. violaceus, and T. minor - are subtroglobiont. They form permanent populations in caves. In fact, they do not show any specific morphological adaptions to caves. - The following 11 species are probably eu- or subtroglobiont, respectively: F. candida, O. absoloni, O. armatus, O. sublegans, P. decipiens, and A. principalis, E. marginalis, I. tigrina, L. nigrescens, N. muscorum, T. vulgaris. They have been found only in single caves or/and we caught some individuals only. - Mesogastrura ojcoviensis, Schaefferia decemoculata, Sch. emucronata, Sch. willemi and Arrhopalites boneti are known as cave-living species, but in our caves we found only some speciemens in some small caves.KeywordsCollembola, Faunistics, Caves, Germany, Harz, Kyffhäuser, Thüringer Wald, Zittauer Gebirge

Discovery and overproduction of novel highly bioactive pamamycins through transcriptional engineering of the biosynthetic gene cluster

Background Pamamycins are a family of highly bioactive macrodiolide polyketides produced by Streptomyces alboniger as a complex mixture of derivatives with molecular weights ranging from 579 to 705 Daltons. The large derivatives are produced as a minor fraction, which has prevented their isolation and thus studies of chemical and biological properties. Results Herein, we describe the transcriptional engineering of the pamamycin biosynthetic gene cluster (pam BGC), which resulted in the shift in production profle toward high molecular weight derivatives. The pam BGC library was constructed by inserting randomized promoter sequences in front of key biosynthetic operons. The library was expressed in Streptomyces albus strain with improved resistance to pamamycins to overcome sensitivity-related host limitations. Clones with modifed pamamycin profles were selected and the properties of engineered pam BGC were studied in detail. The production level and composition of the mixture of pamamycins was found to depend on balance in expression of the corresponding biosynthetic genes. This approach enabled the isolation of known pamamycins and the discovery of three novel derivatives with molecular weights of 663 Da and higher. One of them, homopamamycin 677A, is the largest described representative of this family of natural products with an elucidated structure. The new pamamycin 663A shows extraordinary activity (IC50 2 nM) against hepatocyte cancer cells as well as strong activity (in the one-digit micromolar range) against a range of Gram-positive pathogenic bacteria. Conclusion By employing transcriptional gene cluster refactoring, we not only enhanced the production of known pamamycins but also discovered novel derivatives exhibiting promising biological activities. This approach has the potential for broader application in various biosynthetic gene clusters, creating a sustainable supply and discovery platform for bioactive natural products

The Electronic Structure of 2-Azapentalenes. Photoelectron Spectroscopic Investigations

The He(I) photoelectron spectra of eight 2-azapentalenes, substituted in 1,3-position by electron releasing groups (dimethylamino, ethoxy, and tert-butyl) revealed that the first four ionization energies (6.4–9.3 eV) are due to ionziation from π MO's. This assignment is based on the comparison with the PE data of 1,3-bis(dimethylamino)pentalene (10) and the results of MNDO calculations. The comparison between experiment and calculations suggests that the first two bands are due to ionizations from π MO's mainly localized in the pentalene moiety

Pediatric T-ALL type-1 and type-2 relapses develop along distinct pathways of clonal evolution

The mechanisms underlying T-ALL relapse remain essentially unknown. Multilevel-omics in 38 matched pairs of initial and relapsed T-ALL revealed 18 (47%) type-1 (defined by being derived from the major ancestral clone) and 20 (53%) type-2 relapses (derived from a minor ancestral clone). In both types of relapse, we observed known and novel drivers of multidrug resistance including MDR1 and MVP, NT5C2 and JAK-STAT activators. Patients with type-1 relapses were specifically characterized by IL7R upregulation. In remarkable contrast, type-2 relapses demonstrated (1) enrichment of constitutional cancer predisposition gene mutations, (2) divergent genetic and epigenetic remodeling, and (3) enrichment of somatic hypermutator phenotypes, related to BLM, BUB1B/PMS2 and TP53 mutations. T-ALLs that later progressed to type-2 relapses exhibited a complex subclonal architecture, unexpectedly, already at the time of initial diagnosis. Deconvolution analysis of ATAC-Seq profiles showed that T-ALLs later developing into type-1 relapses resembled a predominant immature thymic T-cell population, whereas T-ALLs developing into type-2 relapses resembled a mixture of normal T-cell precursors. In sum, our analyses revealed fundamentally different mechanisms driving either type-1 or type-2 T-ALL relapse and indicate that differential capacities of disease evolution are already inherent to the molecular setup of the initial leukemia

Frequent and sex-biased deletion of SLX4IP by illegitimate V(D)J-mediated recombination in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) accounts for ∼25% of pediatric malignancies. Of interest, the incidence of ALL is observed ∼20% higher in males relative to females. The mechanism behind the phenomenon of sex-specific differences is presently not understood. Employing genome-wide genetic aberration screening in 19 ALL samples, one of the most recurrent lesions identified was monoallelic deletion of the 5′ region of SLX4IP. We characterized this deletion by conventional molecular genetic techniques and analyzed its interrelationships with biological and clinical characteristics using specimens and data from 993 pediatric patients enrolled into trial AIEOP-BFM ALL 2000. Deletion of SLX4IP was detected in ∼30% of patients. Breakpoints within SLX4IP were defined to recurrent positions and revealed junctions with typical characteristics of illegitimate V(D)J-mediated recombination. In initial and validation analyses, SLX4IP deletions were significantly associated with male gender and ETV6/RUNX1-rearranged ALL (both overall P < 0.0001). For mechanistic validation, a second recurrent deletion affecting TAL1 and caused by the same molecular mechanism was analyzed in 1149 T-cell ALL patients. Validating a differential role by sex of illegitimate V(D)J-mediated recombination at the TAL1 locus, 128 out of 1149 T-cell ALL samples bore a deletion and males were significantly more often affected (P = 0.002). The repeatedly detected association of SLX4IP deletion with male sex and the extension of the sex bias to deletion of the TAL1 locus suggest that differential illegitimate V(D)J-mediated recombination events at specific loci may contribute to the consistent observation of higher incidence rates of childhood ALL in boys compared with girl