102 research outputs found

    Induction of neural crest stem cells from Bardet–Biedl syndrome patient derived hiPSCs

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    Neural crest cells arise in the embryo from the neural plate border and migrate throughout the body, giving rise to many different tissue types such as bones and cartilage of the face, smooth muscles, neurons, and melanocytes. While studied extensively in animal models, neural crest development and disease have been poorly described in humans due to the challenges in accessing embryonic tissues. In recent years, patient-derived human induced pluripotent stem cells (hiPSCs) have become easier to generate, and several streamlined protocols have enabled robust differentiation of hiPSCs to the neural crest lineage. Thus, a unique opportunity is offered for modeling neurocristopathies using patient specific stem cell lines. In this work, we make use of hiPSCs derived from patients affected by the Bardet–Biedl Syndrome (BBS) ciliopathy. BBS patients often exhibit subclinical craniofacial dysmorphisms that are likely to be associated with the neural crest-derived facial skeleton. We focus on hiPSCs carrying variants in the BBS10 gene, which encodes a protein forming part of a chaperonin-like complex associated with the cilium. Here, we establish a pipeline for profiling hiPSCs during differentiation toward the neural crest stem cell fate. This can be used to characterize the differentiation properties of the neural crest-like cells. Two different BBS10 mutant lines showed a reduction in expression of the characteristic neural crest gene expression profile. Further analysis of both BBS10 mutant lines highlighted the inability of these mutant lines to differentiate toward a neural crest fate, which was also characterized by a decreased WNT and BMP response. Altogether, our study suggests a requirement for wild-type BBS10 in human neural crest development. In the long term, approaches such as the one we describe will allow direct comparison of disease-specific cell lines. This will provide valuable insights into the relationships between genetic background and heterogeneity in cellular models. The possibility of integrating laboratory data with clinical phenotypes will move us toward precision medicine approaches

    'Hail England old England my country & home': Englishness and the Local in John Clare’s Writings

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    This article rethinks John Clare's connection to place, as well as the concepts of ‘place’ and ‘the local’ themselves. It argues that the localism of his work was enabled by potential alienation and displacement and was connected to a sense of wider national community. Clare's writings attempt to think of England in two related ways: as a political community brought together at times of threat, and as a community of taste brought together by a way of apprehending the natural world. His early patriotic verse is often strained and unconvincing, but poems such as ‘The Flitting’ present an idea of ‘native poesy’ that embodies the local and the national through careful description of the natural world. However, this idea was itself mediated through metropolitan attempts to reclaim the customs and literature of ‘merry England’. Thus Clare's localism and nationalism are shown to be ambivalent and uncanny

    Genome Analysis Reveals Interplay between 5′UTR Introns and Nuclear mRNA Export for Secretory and Mitochondrial Genes

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    In higher eukaryotes, messenger RNAs (mRNAs) are exported from the nucleus to the cytoplasm via factors deposited near the 5′ end of the transcript during splicing. The signal sequence coding region (SSCR) can support an alternative mRNA export (ALREX) pathway that does not require splicing. However, most SSCR–containing genes also have introns, so the interplay between these export mechanisms remains unclear. Here we support a model in which the furthest upstream element in a given transcript, be it an intron or an ALREX–promoting SSCR, dictates the mRNA export pathway used. We also experimentally demonstrate that nuclear-encoded mitochondrial genes can use the ALREX pathway. Thus, ALREX can also be supported by nucleotide signals within mitochondrial-targeting sequence coding regions (MSCRs). Finally, we identified and experimentally verified novel motifs associated with the ALREX pathway that are shared by both SSCRs and MSCRs. Our results show strong correlation between 5′ untranslated region (5′UTR) intron presence/absence and sequence features at the beginning of the coding region. They also suggest that genes encoding secretory and mitochondrial proteins share a common regulatory mechanism at the level of mRNA export

    Surface rupture of multiple crustal faults in the 2016 Mw 7.8 Kaikōura, New Zealand, earthquake

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    Multiple (>20 >20 ) crustal faults ruptured to the ground surface and seafloor in the 14 November 2016 M w Mw 7.8 Kaikōura earthquake, and many have been documented in detail, providing an opportunity to understand the factors controlling multifault ruptures, including the role of the subduction interface. We present a summary of the surface ruptures, as well as previous knowledge including paleoseismic data, and use these data and a 3D geological model to calculate cumulative geological moment magnitudes (M G w MwG ) and seismic moments for comparison with those from geophysical datasets. The earthquake ruptured faults with a wide range of orientations, sense of movement, slip rates, and recurrence intervals, and crossed a tectonic domain boundary, the Hope fault. The maximum net surface displacement was ∼12  m ∼12  m on the Kekerengu and the Papatea faults, and average displacements for the major faults were 0.7–1.5 m south of the Hope fault, and 5.5–6.4 m to the north. M G w MwG using two different methods are M G w MwG 7.7 +0.3 −0.2 7.7−0.2+0.3 and the seismic moment is 33%–67% of geophysical datasets. However, these are minimum values and a best estimate M G w MwG incorporating probable larger slip at depth, a 20 km seismogenic depth, and likely listric geometry is M G w MwG 7.8±0.2 7.8±0.2 , suggests ≤32% ≤32% of the moment may be attributed to slip on the subduction interface and/or a midcrustal detachment. Likely factors contributing to multifault rupture in the Kaikōura earthquake include (1) the presence of the subduction interface, (2) physical linkages between faults, (3) rupture of geologically immature faults in the south, and (4) inherited geological structure. The estimated recurrence interval for the Kaikōura earthquake is ≥5,000–10,000  yrs ≥5,000–10,000  yrs , and so it is a relatively rare event. Nevertheless, these findings support the need for continued advances in seismic hazard modeling to ensure that they incorporate multifault ruptures that cross tectonic domain boundaries

    John Clare and place

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    This chapter tackles issues of place in the self-presentation and critical reception of John Clare, and pursues it across a number of axes. The argument centres on the placing of Clare both socio-economically and ‘naturally’, and limitations exerted upon perceptions of his work. Interrogating criticism this chapter finds a pervasive awkwardness especially in relation to issues of class and labour. It assesses the contemporary ‘placing’ of Clare, and seemingly unavoidable insensitivities to labour and poverty in the history industry, place-naming, and polemical ecocriticism. It assesses the ways Clare represents place – in poverty, in buildings, in nature – and, drawing on Michel de Certeau, considers the tactics Clare uses to negotiate his place. It pursues trajectories to ‘un-place’ Clare: the flight of fame in Clare’s response to Byron; and the flight of an early poem in songbooks and beyond, across the nineteenth century
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