BILDUNG UND GEBRAUCH VON BEGRIFFEN IN DER PALÄOÖKOLOGIE

During the past 20 years, palaeoecology has established itself as a concept in palaeontology and geology. As in other interdisciplinary sciences, the interchange of methods and terminology between the branches involved has led to changes in the meaning of the terms, and changes or confusion in the corresponding scientific concepts. This calls for stricter adherence to the original definition of the terms in many cases and for their redefinition in others. Starting with a critical review of the scientific and methodological range of palaeoecology, this paper presents a reconsideration of its basic concepts, with proposals concerning the conservation or redefinition of terms and with special regard to terms coined in German literature. It is desirable that similar revisions be undertaken in other language areas in order to attain a stricter, internationalized terminology, preferably substantiated in a dictionary.     

WACHSTUMS-ÄNDERUNGEN IN DER ONTO-GENESE PALÄOZOISCHER AMMONOIDEEN

Ontogenetic allometries (heterauxesis according to Huxley) of about 50 Carboniferous goniatite species from Germany, Spain and USA have been studied by means of geometrical measurements of shell cross sections. They indicate changes of proportions during ontogeny between coiling spiral, umbilical spiral, and whorl width. The allometry constants change suddenly at defined stages. Thus the ontogenetic growth pattern is polyphase, each phase being determined by a different allometric formula.
Ontogenetische Allometrien wurden bei etwa 50 karbonischen Goniatiten-Arten aus Deutschland, Spanien und USA an Hand von Gehäuse-Querschnitten untersucht. Während der Ontogenese erfolgen mehrfach Proportionsverschie-bungen der äußeren Spirale, der Nabelspirale und der Windungsbreite, die sich durch scharfen Wechsel von Allometrie-Konstanten an definierten Stellen aus-drücken. Das Gehäusewachstum erfolgt somit in mehreren Phasen, die von unterschiedlichen Allometrieformeln bestimmt sind.     

PERNICIÖSE EPÖKIE VON PLACUNOPSIS AUF CERATITES

An adult Ceratites semipartitus encrusted by epifaunal Placunopsis ostracina is described. The epizoans are orientated in relation to the slope of the substratum and according to their time of attachment to the ammonoid shell. Geometrical analysis of the orientation leads to the following conclusions: (1) During and after the growth of the last whorl, several, probably 4, swarms of larvae of Placunopsis settled upon the Ceratites specimen. (2) The dead body was for some time kept upright, the living chamber showing upwards. During this time, larvae of Placunopsis became attached again. (3) The ammonoid shell was then laid down, its left flank in contact with the sediment. In this position it was for the last time settled upon by Placunopsis which died whilst juvenile.
Provided that the phases of attachment corresponded to annual spawning periods of Placunopsis , the last whorl of the Ceratites was formed with decreasing velocity of growth within about 4 years.
Placunopsis became attached with its right valve, the posterior end of the body showing upwards, and the direction of growth being declined from the vertical by 65°. Placunopsis either preferred to settle within a distinct zone of the living chamber of the ammonoid close to the lowermost part of the shell or was able to grow up here only. Ceratites semipartitus was therefore probably nectonic.
Both the host and the epizoan were influenced to their disadvantage by their fatal partnership. A relationship of this kind therefore should not be called a symbiosis.     

RNA-binding protein AUF1 represses Dicer expression

MicroRNA (miRNA) biogenesis is tightly regulated by numerous proteins. Among them, Dicer is required for the processing of the precursor (pre-)miRNAs into the mature miRNA. Despite its critical function, the mechanisms that regulate Dicer expression are not well understood. Here we report that the RNA-binding protein (RBP) AUF1 (AU-binding factor 1) associates with the endogenous DICER1 mRNA and can interact with several segments of DICER1 mRNA within the coding region (CR) and the 3′-untranslated region (UTR). Through these interactions, AUF1 lowered DICER1 mRNA stability, since silencing AUF1 lengthened DICER1 mRNA half-life and increased Dicer expression, while overexpressing AUF1 lowered DICER1 mRNA and Dicer protein levels. Given that Dicer is necessary for the synthesis of mature miRNAs, the lowering of Dicer levels by AUF1 diminished the levels of miRNAs tested, but not the levels of the corresponding pre-miRNAs. In summary, AUF1 suppresses miRNA production by reducing Dicer production.     

DIE WIRKUNG KOMBINIERTER ANWENDUNG INSEKTIZIDER PHOSPHORSÄUREESTER UND CARBAMATE AUF DROSOPHILA MELANOGASTER1

Zusammenfassung Die Kontaktwirkung von Phosphorestern, Carbamaten und Kombinationen beider Wirkstoffgruppen auf Drosophila melanogaster wurde untersucht.Auf Grund bestimmter Merkmale der Zeit-Wirkungskurven lassen sich drei verschiedene Typen von Phosphorestern unterscheiden.In Kombination mit subletalen Dosen des reversibel wirkenden Carbamats Isolan werden die Wirkungen der Phosphorester in unterschiedlicher Weise verändert.Die möglichen Ursachen für diese Wirkungsunterschiede und Wirkungsveräderungen werden diskutiert.

---

Summary Sixteen organic phosphorus insecticides and three insecticidal carbamates were tested per se and in combinations against Drosophila melanogaster.Sublethal doses of the carbamate at first accelerated the effect of parathion, paraoxon, chlorthion, malathion, DDVP, trichlorphon, phosphamidon, and mevinphos (type 1). However, later on the time-response curves indicated retardation of mortality and even recovery of the poisoned flies. Similar results were obtained in combinations with guthion, endothion, G 24747, G 24746, diazinon, and diazoxon (type 2), a group of phosphorus esters the timeresponse curves of which under our conditions are not sigmoidal like type 1, but broken and partly showing a tendency to recovery of the flies.The recovery phenomenon in combinations occurred only when the phosphorus ester uptake by the flies was stopped after a fixed time; thus supplies were cut off, degrading systems could inactivate free phosphorus ester and acetylcholinesterase regenerated from carbamate-blockage was not inhibited anew.The typical sigmoidal time-response curves of EPN and thiometon (type 3) were not altered by combination with carbamates; that may indicate absence of effective enzymes for degrading these compounds.

---

---

Kurzfassung der gleichnamigen Dissertation der landwirtschaftlichen Fakultät.     

14-3-3sigma is a p37 AUF1-binding protein that facilitates AUF1 transport and AU-rich mRNA decay

Short-lived cytokine mRNAs contain an AU-rich destabilizing element (ARE). AUF1 proteins bind the ARE, undergo shuttling, and promote cytoplasmic ARE-mRNA decay through a poorly understood mechanism. We therefore identified AUF1-interacting proteins that may play a role in ARE-mRNA decay. We used mass-spectrometry to identify 14-3-3sigma protein as an AUF1-interacting protein. 14-3-3sigma binds selectively and strongly to p37 AUF1 and to a lesser extent to the p40 isoform, the two isoforms most strongly associated with ARE-mRNA decay, but not to the two larger isoforms, p42 and p45. The 14-3-3sigma interaction site on p37 was mapped to a region found only in the two smaller AUF1 isoforms and which overlaps a putative nuclear localization signal (NLS). Stable overexpression of 14-3-3sigma significantly increased cytoplasmic accumulation of p37 AUF1 and reduced the steady-state level and half-life of a reporter ARE-mRNA. siRNA silencing of AUF1 eliminated the effect of 14-3-3sigma overexpression. 14-3-3sigma therefore binds to p37 AUF1, retains it in the cytoplasm probably by masking its NLS, and enhances rapid turnover of ARE-mRNAs.     

DIE WIRKUNG VERSCHIEDENER, ÜBER DIE PFLANZE ZUGEFÜHRTER ANTIBIOTICA AUF ENTWICKLUNG UND FERTILITÄT DER SCHWARZEN BOHNENBLATTLAUS APHIS FABAE

Zusammenfassung Unter dem Einfluss verschiedener Antibiotica wird die Larvalentwicklung von Bohnenblattläusen stark gehemmt. Diese Substanzen bedingen ausserdem geringere Größe und vermindertes Gewicht der Aphiden im Vergleich zu unbehandelten Kontrolltieren. Je nach Art und Konzentration des verwendeten Antibioticums bleiben die Aphiden entweder völlig steril oder ihre Reproduktionsfähigkeit wird unterschiedlich stark herabgesetzt. Bereits eine einbis zweitägige Terramycinaufnahme durch Aphiden während des ersten Larvenstadiums ist ausreichend, um beim adulten Tier völlige Sterilität hervorzurufen.

---

Summary A considerable delay in larval development of black bean aphids was observed when they were kept permanently on Vicia faba plants in solutions containing antibiotics. The reduction in the weight and size of the aphids on treated plants were also marked in comparison with those on untreated plants. Furthermore, total sterility was observed in certain cases and reduced reproductive rate in others. This effect was related to the chemical constitution, and the concentration of the antibiotics tested. The most effective substances were: terramycin, aureomycin, tetracyclin, chloramphenicol, and reverin. All other antibiotics had none or only a slight impact on reproduction. Even when young larvae fed for a short period (one or two days) on terramycin treated plants, total sterility resulted. The relation between the larval development and reproductive rate of aphids, and the destruction of their symbiotes by antibiotics is discussed.

     

Sequence requirements for RNA binding by HuR and AUF1

The stability of RNAs bearing AU-rich elements in their 3'-UTRs, and thus the level of expression of their protein products, is regulated by interactions with cytoplasmic RNA-binding proteins. Binding by HuR generally leads to mRNA stabilization and increased protein production, whereas binding by AUF1 isoforms generally lead to rapid degradation of the mRNA and reduced protein production. The exact nature of the interplay between these and other RNA-binding proteins remains unclear, although recent studies have shown close interactions between them and even suggested competition between the two for binding to their cognate recognition sequences. Other recent reports have suggested that the sequences recognized by the two proteins are different. We therefore performed a detailed in vitro analysis of the binding site(s) for HuR and AUF1 present in androgen receptor mRNA to define their exact target sequences, and show that the same sequence is contacted by both proteins. Furthermore, we analysed a proposed HuR target within the 3'-UTR of MTA1 mRNA, and show that the contacted bases lie outside of the postulated motif and are a better match to a classical ARE than the postulated motif. The defining features of these HuR binding sites are their U-richness and single strandedness.     

Linc-RoR promotes c-Myc expression through hnRNP I and AUF1

Linc-RoR was originally identified to be a regulator for induced pluripotent stem cells in humans and it has also been implicated in tumorigenesis. However, the underlying mechanism of Linc-RoR-mediated gene expression in cancer is poorly understood. The present study demonstrates that Linc-RoR plays an oncogenic role in part through regulation of c-Myc expression. Linc-RoR knockout (KO) suppresses cell proliferation and tumor growth. In particular, Linc-RoR KO causes a significant decrease in c-Myc whereas re-expression of Linc-RoR in the KO cells restores the level of c-Myc. Mechanistically, Linc-RoR interacts with heterogeneous nuclear ribonucleoprotein (hnRNP) I and AU-rich element RNA-binding protein 1 (AUF1), respectively, with an opposite consequence to their interaction with c-Myc mRNA. While Linc-RoR is required for hnRNP I to bind to c-Myc mRNA, interaction of Linc-RoR with AUF1 inhibits AUF1 to bind to c-Myc mRNA. As a result, Linc-RoR may contribute to the increased stability of c-Myc mRNA. Although hnRNP I and AUF1 can interact with many RNA species and regulate their functions, with involvement of Linc-RoR they would be able to selectively regulate mRNA stability of specific genes such as c-Myc. Together, these results support a role for Linc-RoR in c-Myc expression in part by specifically enhancing its mRNA stability, leading to cell proliferation and tumorigenesis.     

GENERAL ACCOUNTS ON THE OÖCYTE GROWTH AND THE IDENTIFICATION OF VITELLOGENIN BY MEANS OF IMMUNOSPECIFICITY IN THE COCKROACH, BLATTELLA GERMANICA (L.)

The female Blattella germanica pushes out an oötheca 11 days after adult ecdysis and carries it for about 25 days until nymphs hatch out. The terminal oöcyte begins to accumulate yolk abruptly 4 or 5 days after adult ecdysis and grows fully on day 10 when its volume reaches 180 times as compared to that at adult ecdysis.
Vitellogenin, the vitellogenic female-specific protein, was identified by immunoelectrophoresis and Ouchterlony's test. Fluctuation of vitellogenin in the blood, ovary and embryo at various stages was analyzed. Vitellogenin appears in the female blood 3 or 4 days after adult ecdysis and disappears soon after terminal oöcytes have been released to an oötheca. In the ovary, it appears 4 or 5 days after adult ecdysis and disappears when terminal oöcytes leave the ovary. It remains in embryos until shortly before hatching, but is absent in newly hatched nymphs.     

AUF1在病毒感染及相关炎症反应中的调控作用

富含AU元件的RNA结合蛋白1(AU-rich element binding factor 1,AUF1)具有剪接加工前体mRNA、转运和降解成熟mRNA的功能,同时调节带有富含AU元件(AU-rich element,ARE)的mRNA翻新。AUF1通过介导炎性细胞因子及其反应从而控制炎症进程。研究表明,AUF1与肠道病毒71型的内部核糖体进入位点(internal ribosome entry site,IRES)结合并与其交互负性调节病毒翻译与复制,它还可被募集到柯萨奇病毒B3型和肠道病毒71型诱导的应激颗粒中。