Mammalian telomeres stabilize chromosome ends as a result of their assembly into a peculiar form of chromatin comprising a complex of non-histone proteins named shelterin. TRF2, one of the shelterin components, binds to the duplex part of telomeric DNA and is essential to fold the telomeric chromatin into a protective cap. Although most of the human telomeric DNA is organized into tightly spaced nucleosomes, their role in telomere protection and how they interplay with telomere-specific factors in telomere organization is still unclear. In this study we investigated whether TRF2 can regulate nucleosome assembly at telomeres.By means of chromatin immunoprecipitation (ChIP) and Micrococcal Nuclease (MNase) mapping assay, we found that the density of telomeric nucleosomes in human cells was inversely proportional to the dosage of TRF2 at telomeres. This effect was not observed in the G1 phase of the cell cycle but appeared coincident of late or post-replicative events. Moreover, we showed that TRF2 overexpression altered nucleosome spacing at telomeres increasing internucleosomal distance. By means of an in vitro nucleosome assembly system containing purified histones and remodeling factors, we reproduced the short nucleosome spacing found in telomeric chromatin. Importantly, when in vitro assembly was performed in the presence of purified TRF2, nucleosome spacing on a telomeric DNA template increased, in agreement with in vivo MNase mapping.Our results demonstrate that TRF2 negatively regulates the number of nucleosomes at human telomeres by a cell cycle-dependent mechanism that alters internucleosomal distance. These findings raise the intriguing possibility that telomere protection is mediated, at least in part, by the TRF2-dependent regulation of nucleosome organization.

Based on uncharted evidence from Italo-Romance, we describe and discuss three types of matrix clauses, i.e. jussives, concessives and optatives, which reveal a certain degree of consistency but also display different patterns of microvariation. We show how such clauses may be introduced by complementizers, whose insertion is strictly dependent on the utterance of speech-act material at the outset of the sentence. The variation in the overt realization of the complementizers and the utterance of initial interjections conveys different pragmatic information. We finally interpret the morpho-syntactic behaviour of jussive, concessive and optative matrix clauses through the interplay of three semantico-syntactic variables, i.e. beyond-Force, Mood and Modality.

This paper explores a novel case of contact-induced change due to micro-contact within Italy, where various Italo-Romance languages coexist (Standard Italian, Italiano Regionale ‘regional Italian’, and numerous local languages). Although morphosyntactic change due to micro-contact is probably widespread across Italy, it has received almost no attention in the literature. This case study involves the complementizer system of the local language Ferentinese (Southern Lazio), which underwent restructuring over a very brief period. I claim that this change is a case of downward reanalysis from Force to Fin within the split CP, triggered by the regression of the subjunctive and its subsequent replacement by a new complementation strategy. In turn, I argue that this change was the by-product of an increase in the number of complementizers in the language, from two to three, due to micro-contact between Ferentinese and Italiano Regionale. Crucially, the latter furnished a complementizer form (che) identical to one already present in the Ferentinese system, leading to reanalysis. Thus, in addition to reporting on a novel case of micro-contact in Italy, this paper illustrates one pathway to the genesis of a rare three-way complementizer system and sketches an initial typology of how related complementizer systems have changed in diachrony.

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