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Reactivation of the inactive X chromosome is a hallmark epigenetic event during reprogramming of mouse female somatic cells to induced pluripotent stem cells (iPSCs). This involves global structural remodeling from a condensed, heterochromatic into an open, euchromatic state, thereby changing a transcriptionally inactive into an active chromosome. Despite recent advances, very little is currently known about the molecular players mediating this process and how this relates to iPSC-reprogramming in general. To gain more insight, here we perform a RNAi-based knockdown screen during iPSC-reprogramming of mouse fibroblasts. We discover factors important for X chromosome reactivation (XCR) and iPSC-reprogramming. Among those, we identify the cohesin complex member SMC1a as a key molecule with a specific function in XCR, as its knockdown greatly affects XCR without interfering with iPSC-reprogramming. Using super-resolution microscopy, we find SMC1a to be preferentially enriched on the active compared with the inactive X chromosome and that SMC1a is critical for the decompacted state of the active X. Specifically, depletion of SMC1a leads to contraction of the active X both in differentiated and in pluripotent cells, where it normally is in its most open state. In summary, we reveal cohesin as a key factor for remodeling of the X chromosome from an inactive to an active structure and that this is a critical step for XCR during iPSC-reprogramming.

The mammalian germline is characterized by extensive epigenetic reprogramming during its development into functional eggs and sperm. Specifically, the epigenome requires resetting before parental marks can be established and transmitted to the next generation. In the female germline, X-chromosome inactivation and reactivation are among the most prominent epigenetic reprogramming events, yet very little is known about their kinetics and biological function. Here, we investigate X-inactivation and reactivation dynamics using a tailor-made in vitro system of primordial germ cell-like cell (PGCLC) differentiation from mouse embryonic stem cells. We find that X-inactivation in PGCLCs in vitro and in germ cell-competent epiblast cells in vivo is moderate compared to somatic cells, and frequently characterized by escaping genes. X-inactivation is followed by step-wise X-reactivation, which is mostly completed during meiotic prophase I. Furthermore, we find that PGCLCs which fail to undergo X-inactivation or reactivate too rapidly display impaired meiotic potential. Thus, our data reveal fine-tuned X-chromosome remodelling as a critical feature of female germ cell development towards meiosis and oogenesis. This work was supported by the Spanish Ministry of Science, Innovation and Universities (BFU2014-55275-P, BFU2017-88407-P to B.P.), the Agencia Estatal de Investigación (AEI) (EUR2019-103817 to B.P.), the AXA Research Fund (to B.P.) and the Agencia de Gestio d’Ajuts Universitaris i de Recerca (AGAUR, 2017 SGR 346 to B.P.). We would like to thank the Spanish Ministry of Economy, Industry and Competitiveness (MEIC) to the EMBL partnership and to the “Centro de Excelencia Severo Ochoa.” We also acknowledge support of the CERCA Programme of the Generalitat de Catalunya. N.A. is supported by an EMBO postdoctoral fellowship (LTF 695-2019). J.S. and M.B. were supported by La Caixa International PhD Fellowships and J.S. by a travel grant from the Company of Biologists (Development Journal). P.A. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 751651

The spatial organization of genomes is becoming increasingly understood. In mammals, where it is most investigated, this organization ties in with transcription, so an important research objective is to understand whether gene activity is a cause or a consequence of genome folding in space. In this regard, the phenomena of X-chromosome inactivation and reactivation open a unique window of investigation because of the singularities of the inactive X chromosome. Here we focus on the cause-consequence nexus between genome conformation and transcription and explain how recent results about the structural changes associated with inactivation and reactivation of the X chromosome shed light on this problem. This work was supported by the Spanish Ministry of Science, Innovation and Universities and the Agencia Estatal de Investigacion (AEI, BFU2017-88407-P, EUR2019-103817 to B.P.), the AXA Research Fund (to B.P.) and the Agencia de Gestio d'Ajuts Universitaris i de Recerca (AGAUR, 2017 SGR 346 to B.P.). We would like to thank the Spanish Ministry of Economy, Industry and Competitiveness (MEIC) to the EMBL partnership and to the “Centro de Excelencia Severo Ochoa”. We also acknowledge support of the CERCA Programme of the Generalitat de Catalunya. M.B. is supported by an EMBO postdoctoral fellowship (ALTF 682–2021). G.J.F is supported by NSERC (Discovery Grant RGPIN-2020-06377).

Drei junge Forschende aus Theologie und Religionswissenschaft (ReWi) unterhalten sich ganz informell über Interdisziplinarität: über Chancen und Herausforderungen, Konkurrenz und Synergien. Die Diskutierenden befinden sich in unterschiedlichen Stadien ihrer Forschungsviten und richten ihren Blick aufs große Ganze: Wem gehört die Religionsforschung? Three young researchers from Theology and Religious Studies chat about interdisciplinarity, reflecting on its particular opportunities and challenges, competitiveness and synergies. While at different stages of their academic carreers, all three consider the bigger picture: Who owns research on religion?

Im vorliegenden Beitrag denke ich über die interdisziplinäre Zusammenarbeit von Religionswissenschaft und katholischer Theologie sowie allgemein über das Verhältnis der beiden Fächer zueinander nach. Auf Seiten der Theologie wird die Methodik der Komparativen Theologie als notwendige Querschnittsaufgabe (Klaus von Stosch) eingefordert und als Brückenschlag zur interdisziplinären Verständigung präsentiert. Zu diesem Zweck wird das Problemfeld illustriert und die Theologie wissenschaftstheoretisch eingeordnet. Geleitet werden diese Überlegungen durch diskurstheoretische Annahmen in Anschluss an Jürgen Habermas. Die zentralen Gedanken dieses Beitrags lauten: Mittels der Methode der Komparativen Theologie kommt die Theologie Wissenschaftsstandards nach. Die Komparative Theologie avanciert darüber hinaus zu einem Treffpunkt, bei dem die Zusammenarbeit mit der Religionswissenschaft möglich wird. In this article I reflect on the interdisciplinary cooperation between scientific studies of religions and (Catholic) theology as well as on the relationship between the two disciplines in general. On the part of theology, the methodology of comparative theology is called for as a necessary cross-sectional task (Klaus von Stosch) and presented as a bridge to interdisciplinary understanding. To this end, the problem area is illustrated and theology will be reflected before the backdrop of a theory of science. These considerations are guided by discourse-theoretical assumptions following Jürgen Habermas. The central ideas of this article are: By means of the method of comparative theology, theology complies with scientific standards. Furthermore, comparative theology advances to a meeting point where cooperation with religious studies becomes possible.

A hallmark of chromosome organization is the partition into transcriptionally active A and repressed B compartments, and into topologically associating domains (TADs). Both structures were regarded to be absent from the inactive mouse X chromosome, but to be re-established with transcriptional reactivation and chromatin opening during X-reactivation. Here, we combine a tailor-made mouse iPSC reprogramming system and high-resolution Hi-C to produce a time course combining gene reactivation, chromatin opening and chromosome topology during X-reactivation. Contrary to previous observations, we observe A/B-like compartments on the inactive X harbouring multiple subcompartments. While partial X-reactivation initiates within a compartment rich in X-inactivation escapees, it then occurs rapidly along the chromosome, concomitant with downregulation of Xist. Importantly, we find that TAD formation precedes transcription and initiates from Xist-poor compartments. Here, we show that TAD formation and transcriptional reactivation are causally independent during X-reactivation while establishing Xist as a common denominator., Both A/B compartments and TADs are thought to be absent from the inactive X chromosome, but to be re-established with transcriptional reactivation and chromatin opening during X-reactivation. Here, the authors characterise gene reactivation, chromatin opening and chromosome topology during X-reactivation, observe A/B-like compartments on the inactive X that guide TAD formation independently of transcription during X-reactivation.

Mt. Etna is one of the most protrusive features of the eastern coastline of Sicily, Italy. As Europe’s most active volcano it has been studied extensively to reveal its geodynamic setting, plumbing system and due to the constant monitoring of the volcano edifice the prediction of the risk future events is sophisticated at Mt. Etna.The eruptive activity has been divided according to the age into 6 stages: (1) “Tholeiitic Stage”, was active between 600-320 ka ago, (2) the “Timpe Stage” between 220 and 110 ka ago, (3) the “Ancient Alcaline Volcanism” between 110 and 65 ka ago and (4) the “Ellittico Stage” between 57 and 15 ka ago (5) the “Mongibello Stage” from 15 ka ago until 1971 and (6) the “post -1971 Stage” active since 1971 (Casetta et al., 2019).The lava propagating through the Etnean plumbing system generated a complex network consisting of sills and dykes responsible for the formation of the summit craters and a plethora of eccentric cones that cover the flanks of the volcano.We studied whole rock and mineral chemistry of the lavas from three eccentric cones (Monte Spagnolo, Monte Fiori and Monte Rossi) and the 2002/2003 southern flank lava flow. All lavas are characterized by trachytic texture with variable modal composition of olivine, clinopyroxene and plagioclase phenocrysts. Euhedral and skeletal olivine phenocrysts can be distinguished into three main groups; a) normal zoning, b) inverse zoning, and c) patchy appearance with melt inclusions of andesitic and trachytic composition. The Monte Spagnolo whole rock composition has an Mg# ranging between 52-54 and 10.7 wt% CaO , being are the most primitive lavas among the sampled outcrops whereas the Monte De Fiore lavas are the most evolved since the Mg# ranges from 48.6 to 49.2 and the CaO content from 11 to 11.2 wt%. Both, Monti Rossi and the 2002/2003 lava flow are more evolved than the Monte Spagnolo since they have Mg# ~ 50 and 49-49.3 respectively. The CaO concentration in both outcrops is relatively constant ranging around 10.5 wt%.The olivine compositions follow the same trend as their whole rocks. The most MgO-rich olivine (Fo=88.9 %) was found in the Monte Spagnolo lavas. This olivine is of magmatic origin and cannot be considered as mantle derived xenocryst since the NiO content is low (NiO=0.17 – 0.2 wt%) and the CaO-content high (CaO=0.24 – 0.26 wt%). The most evolved lavas from Monte De Fiore have the lowest Fo-content (Fo=75 - 78 %). Olivine from all samples has a characteristic inverse zonation with, at Monti Rossi and 2002/2003 lava flow, Fo-content in the core ranging from 69% to 75% and in the rim from 77% to 80% respectively.In conclusion, the studied eccentric cones show extensive magma mixing as can be inferred from the olivine inverse zoning. Monte Spagnolo lavas represent the most primitive magma formed at high temperatures (olivine skeletal growing) and the Monte De Fiore lavas the most evolved magma. Casetta et al., 2019. International Geology Review, DOI: 10.1080/00206814.2019.1610979

The streamlined catalytic access to enantiopure allylic amines as valuable precursors towards chiral β- and γ-aminoalcohols as well as α- and β-aminoacids is desirable for industrial purposes. In this article an enantioselective method is described that transforms achiral allylic alcohols and N-tosylisocyanate in a single step into highly enantioenriched N-tosyl protected allylic amines via an allylic carbamate intermediate. The latter is likely to undergo a cyclisation-induced [3,3]-rearrangement catalysed by a planar chiral pentaphenylferrocene palladacycle in cooperation with a tertiary amine base. The otherwise often indispensable activation of palladacycle catalysts by a silver salt is not required in the present case and there is also no need for an inert gas atmosphere. To further improve the synthetic value, the rearrangement was used to form dimethylaminosulfonyl-protected allylic amines, which can be deprotected under non-reductive conditions.

A long-standing mystery in the field of Polycomb and Trithorax regulation is how these proteins, which are highly conserved between flies and mammals, can regulate several hundred equally highly conserved target genes, but recognise these targets via cis-regulatory elements that appear to show no conservation in their DNA sequence. These elements, termed Polycomb/Trithorax response elements (PRE/TREs or PREs), are relatively well characterised in flies, but their mammalian counterparts have proved to be extremely difficult to identify. Recent progress in this endeavour has generated a wealth of data and raised several intriguing questions. Here, we ask why and to what extent mammalian PREs are so different to those of the fly. We review recent advances, evaluate current models and identify open questions in the quest for mammalian PREs. Electronic supplementary material The online version of this article (doi:10.1007/s00412-015-0539-4) contains supplementary material, which is available to authorized users.

A regio- and enantioselective tandem reaction is reported capable of directly transforming readily accessible achiral allylic alcohols into chiral sulfonyl-protected allylic amines. The reaction is catalyzed by the cooperative action of a chiral ferrocene palladacycle and a tertiary amine base and combines high step-economy with operational simplicity (e.g. no need for inert-gas atmosphere or catalyst activation). Mechanistic studies support a Pd(II)-catalyzed [3,3] rearrangement of allylic carbamates--generated in situ from the allylic alcohol and an isocyanate--as the key step, which is followed by a decarboxylation.

Eine regio- und enantioselektive Tandemreaktion, die leicht zugangliche achirale Allylalkohole direkt in chirale sulfonylgeschutzte Allylamine uberfuhrt, wird beschrieben. Die Reaktion wird durch Kooperation eines chiralen Ferrocen-Palladacyclus und einer tertiaren Amin-Base katalysiert und kombiniert hohe Stufenokonomie mit leichter Handhabung (ohne Inertgasatmosphare oder Katalysatoraktivierung). Mechanistische Studien stutzen eine PdII-katalysierte [3,3]-Umlagerung eines Allylcarbamats – in situ erzeugt aus einem Allylalkohol und einem Isocyanat – als Schlusselschritt, dem eine Decarboxylierung folgt.

The streamlined catalytic access to enantiopure allylic amines as valuable precursors towards chiral β- and γ-aminoalcohols as well as α- and β-aminoacids is desirable for industrial purposes. In this article an enantioselective method is described that transforms achiral allylic alcohols and N-tosylisocyanate in a single step into highly enantioenriched N-tosyl protected allylic amines via an allylic carbamate intermediate. The latter is likely to undergo a cyclisation-induced [3,3]-rearrangement catalysed by a planar chiral pentaphenylferrocene palladacycle in cooperation with a tertiary amine base. The otherwise often indispensable activation of palladacycle catalysts by a silver salt is not required in the present case and there is also no need for an inert gas atmosphere. To further improve the synthetic value, the rearrangement was used to form dimethylaminosulfonyl-protected allylic amines, which can be deprotected under non-reductive conditions.

A catalytic asymmetric method for the transformation of allylic alcohols into sulfonyl-protected chiral allylic amines is presented.

An raumliche Bezugseinheiten werden in der Regel zahlreiche und verschiedenartige Anforderungen gestellt. So sollen sie moglichst aussagekraftig, hierarchisch aufgebaut, flachendeckend vorhanden, lange gultig, vielfaltig auswertbar und interpretierbar, mithin universell anwendbar, kombinationsfahig, gleich gros und von gleicher Form, gebrauchlich bezeichnet und anschaulich sein (Sandner, 1989). Es lohnt sich, daraufhin zunachst verschiedenartige raumliche Bezugseinheiten miteinander zu vergleichen (Tabelle 1).

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