Regulation and transcript analysis of the ceroperon responsible for quorum sensing in Rhodobacter sphaeroides 2.4.1

Rhodobacter sphaeroides 2.4.1 is a Gram negative facultative photoheterotrophic bacterium that has been shown to have an N-acyl homoserine lactone-based quorum sensing system called cer for c&barbelow;ommunity e&barbelow;scape r&barbelow;esponse. The cer ORFs are cerR, the transcriptional regulator, cerI, the autoinducer synthase and cerA , whose function is unknown. The autoinducer molecule, 7,8- cis-N-(tetradecenoyl) homoserine lactone, has been characterized. The objective of this study was to identify an environmental stimulus that influences the regulation of cerRAI and, to characterize transcription of the cer operon. ^ A cerR::lacZ transcriptional fusion was made and β-Galactosidase assays were performed in R. sphaeroides 2.4.1 strains, wild type, AP3 (CerI−) and AP4 (CerR−). The cerR::lacZ β-Galactosidase assays were used as an initial survey of the mode of regulation of the Cer system. A cerA::lacZ translational fusion was created and was used to show that cerA can be translated. The presence of 7,8-cis-N-(tetradecenoyl) homoserine lactone was detected from R. sphaeroides strains wild type and AP4 (CerR−) using a lasR::lacZ translational fusion autoinducer bioassay. The cerR::lacZ transcriptional fusion in R. sphaeroides 2.4.1 wild type was tested under different environmental stimuli, such as various carbon sources, oxygen tensions, light intensities and culture media to determine if they influence transcription of the cer ORFs. Although lacZ assay data implicated high light intensity at 100 W/m2 to stimulate cer transcription, quantitative Northern RNA data of the cerR transcript showed that low light intensity at 3 W/m2 is at least one environmental stimulus that induces cer transcription. This finding was supported by DNA microarray analysis. Northern analysis of the cerRAI transcript provided evidence that the cer ORFs are co-transcribed, and that the cer operon contains two additional genes. Bioinformatics was used to identify genes that may be regulated by the Cer system by identifying putative lux box homologue sequences in the presumed promoter region of these genes. Genes that were identified were fliQ, celB and calsymin, all implicated in interacting with plants. Primer extension was used to help localize cis-elements in the promoter region. The cerR::lacZ transcriptional fusion was monitored in a subset of different global DNA binding transcriptional regulator mutant strains of R. sphaeroides 2.4.1. Those regulators involved in maintaining an anaerobic photosynthetic lifestyle appeared to have an effect. Collectively, the data imply that R. sphaeroides 2.4.1 activates the Cer system when grown anaerobic photosynthetically at low light intensity, 3 W/m2, and it may be involved in an interaction with plants. ^

Na 1 Nachlass Max Horkheimer, 606 - Vorlesung: "Einführung in die Philosophie der Gegenwart" sowie drei Vorträge (p. VIII 2, 1 - VIII 2, 2-4)

Vorlesung: "Einführung in die Philosophie der Gegenwart", SS 1926, Typoskript mit eigenhändigen Korrekturen, 185 Blatt; Vortrag: "Über Sinn und Grenze einer soziologischen Behandlungen der Philosophie", 1928 (?), Typsokript mit eigenhändigen Korrekturen, 10 Blatt (GS 11, S. 209-220); Vortrag, gehalten zu Beginn der Vorlesung: "Max Scheler (1874-1928)", "Einführung in die Geschichtsphilosophie", SS 1928, Typoskript mit eigenhändigen Korrekturen, 13 Blatt (GS 11, 145-157); Vortrag: "Über Kantische und moderne Ethik" Typsokript mit eigenhändigen Korrekturen, 6 Blatt (GS 11, S. 138-144);

Na 1 Nachlass Max Horkheimer, 682 - "Antisemitism among American Labor" (p. IX 146.2-4 - IX 146.5-23)

"Antisemitism and American Labor. A Research Project of the Institut of Social Research", Januar 1944 (revised June 1944); a) als Typoskript vervielfältigt, 14 Blatt; b) Typoskript, 14 Blatt; Institut of Social Research: "Project an Antisemitism and American Labor", Januar 1944; a) Typoskript, 18 Blatt; b) Typoskript, mit handschriftlichen Korrekturen, 17 Blatt, c) Teilstück, Typoskript mit handschriftlichen Korrekturen, 1 Blatt; d) Teilstück, Typoskript mit handschriftlichen Korrekturen, 1 Blatt; e) Teilstück, Typoskript mit handschriftlichen Korrekturen, 5 Blatt; f) Teilstück, Typoskript mit handschriftlichen Korrekturen, 4 Blatt; "Project on Antisemitism an American Labor", Dezember 1943; a) Typoskript mit handschriftlichen Korrekturen, 18 Blatt; b) Typoskript mit handschriftlichen Korrekturen von Theodor W. Adorno, 17 Blatt; c) Typoskript mit handschriftlichen Korrekturen, 12 Blatt; Memoranden 1941-1949; Adorno, Theodor W. to Löwenthal, Leo: "Supplement to the Memorandum of 7/28/49 by Pollock, Friedrich re Labor Study", 18.09.1949. Typoskript, 6 Blatt; Adorno, Theodor W.: "Memorandum re: Antisemitism among American Labor, as edited by the Bureau of Applied Social Research", 19.07.1949. Typoskript, 8 Blatt; "Expenses for Project: Antisemitism among Labor, june 1, 1944- May 31,1945". Typoskript, 1 Blatt; Institut of Social Research: "Interim Memorandum on Progress of Project on Antisemitism within Labor", 04.09.1944. Typoskript, 11 Blatt; Institut of Social Research: "Re: Project on Labor and Antisemitism. Difficulties to be expected", 21.03.1944. Typoskript, 3 Blatt; "Re: Project on Labor and Antisemitism. Plants to be Contacted", 21.03.1944. Typoskript, 2 Blatt; "Some Remarks to Dr. Gelle's Report 'Der deutsche Progrom, a, 10. November 1938'", 11.03.1944. Typoskript, 12 Blatt; Adorno, Theodor W. ?: "Adress to ameeting of the Jewish Labor Committee, January 20th, 1944, los Angeles". Typoskript mit eigenhändigen Ergänzungen, 2 Blatt; Pollock, Friedrich: "Re: Sherman", 31.12.1943, 1 Blatt; "Memorandum re: Jewish Labor Committee", 23.12.1943. Typoskript mit handschriftlichen Korrekturen, 2 Blatt; "Tentative Budget for a Trial Survey on Antisemitism among American Labor", 23.12.1943. Typoskript, 1 Blatt; "Council for Democracy. Survey on Antisemitism. Hartford, Conn., late 1941". Typoskript, 4 Blatt; "Council for Democracy. Survey on Antisemitism. Terre Haute, Ind.". Typoskript, 2 Blatt; Horkheimer, Max: Eigenhändige Notizen zum Projekt, 3 Blatt; "Some heading lind", handschriftlichen Notizen, 1 Blatt; Institut of Social research: "Instructuins", Fragebogen, als Typoskript vervielfältigt, 3 Blatt; "Instructions for Interviews on Attitudes of Workers and White Collar Workers towards Jews". Als Typoskript vervielfältigt, 1 Blatt; Horkheimer, Max: 1 Briefentwurf an Friedrich Pollock, ohne Ort, ohne Datum, 1 Blatt; Pollock, Friedrich: 3 Briefe an Max Horkheimer, ohne Ort, 1943, 3 Blatt; Sherman, Charles B.: 1 Brief mit Unterschrift an Friedrich Pollock, New York, 23.12.1943; 3 Briefe von Friedrich Pollock, New York, 1943-1944, 5 Blatt;

CaCO3, foraminifer fragmentation, benthic carbon isotopes, coarse lithic counts and radiogenic isotopes (Sr, Nd, Pb) of the Pliocene and earliest Pleistocene terrigenous component (3.3-2.4 Ma) of IODP Site 306-U1313

We present Plio-Pleistocene records of sediment color, %CaCO3, foraminifer fragmentation, benthic carbon isotopes (d13C) and radiogenic isotopes (Sr, Nd, Pb) of the terrigenous component from IODP Site U1313, a reoccupation of benchmark subtropical North Atlantic Ocean DSDP Site 607. We show that (inter)glacial cycles in sediment color and %CaCO3 pre-date major northern hemisphere glaciation and are unambiguously and consistently correlated to benthic oxygen isotopes back to 3.3 million years ago (Ma) and intermittently so probably back to the Miocene/Pliocene boundary. We show these lithological cycles to be driven by enhanced glacial fluxes of terrigenous material (eolian dust), not carbonate dissolution (the classic interpretation). Our radiogenic isotope data indicate a North American source for this dust (~3.3-2.4 Ma) in keeping with the interpreted source of terrestrial plant wax-derived biomarkers deposited at Site U1313. Yet our data indicate a mid latitude provenance regardless of (inter)glacial state, a finding that is inconsistent with the biomarker-inferred importance of glaciogenic mechanisms of dust production and transport. Moreover, we find that the relation between the biomarker and lithogenic components of dust accumulation is distinctly non-linear. Both records show a jump in glacial rates of accumulation from Marine Isotope Stage, MIS, G6 (2.72 Ma) onwards but the amplitude of this signal is about 3-8 times greater for biomarkers than for dust and particularly extreme during MIS 100 (2.52 Ma). We conclude that North America shifted abruptly to a distinctly more arid glacial regime from MIS G6, but major shifts in glacial North American vegetation biomes and regional wind fields (exacerbated by the growth of a large Laurentide Ice Sheet during MIS 100) likely explain amplification of this signal in the biomarker records. Our findings are consistent with wetter-than-modern reconstructions of North American continental climate under the warm high CO2 conditions of the Early Pliocene but contrast with most model predictions for the response of the hydrological cycle to anthropogenic warming over the coming 50 years (poleward expansion of the subtropical dry zones).

International Symposium 'Marathon, the day after'. Delfos, Grecia, 2-4 julio de 2010

Fil: Nelli, María Florencia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

International Symposium 'Marathon, the day after'. Delfos, Grecia, 2-4 julio de 2010

Fil: Nelli, María Florencia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.