The transition from proliferating precursor cells to post-mitotic differentiated cells is crucial for development, tissue homeostasis, and tumor suppression. To study cell-cycle exit during differentiation in vivo, we developed a conditional knockout and lineage-tracing system for Caenorhabditis elegans. Combined lineage-specific gene inactivation and genetic screening revealed extensive redund...

To investigate the function of SWI/SNF in site-specific chromatin remodeling at promoters, we have used a purified system to analyze its distribution, function, and retention following recruitment by a sequence-specific transcription activator. Activator recruitment of SWI/SNF bound the complex to promoter proximal nucleosomes and led to localized nucleosome disruption. However, retention of SW...

The Saccharomyces cerevisiae SWI1, SWI2 (SNF2), SWI3, SNF5, and SNF6 gene products play a crucial role in the regulation of transcription. We provide here direct biochemical evidence that all five SWI/SNF polypeptides are components of a large multisubunit complex. These five polypeptides coelute from a gel-filtration column with an apparent molecular mass of approximately 2 MDa. The five SWI/S...

Susceptibility weighted imaging (SWI) combined with the FLAIR sequence provides the ability to depict in vivo the perivenous location of inflammatory demyelinating lesions - one of the most specific pathologic features of multiple sclerosis (MS). In addition, in MS white matter (WM) lesions, gadolinium-based contrast media (CM) can increase vein signal loss on SWI. This report focuses on two ca...

Alterations in chromatin play an important role in oncogenic transformation, although the underlying mechanisms are often poorly understood. The SWI/SNF complex contributes to epigenetic regulation by using the energy of ATP hydrolysis to remodel chromatin and thus regulate transcription of target genes. SNF5, a core subunit of the SWI/SNF complex, is a potent tumor suppressor that is specifica...

BACKGROUND Susceptibility-weighted imaging (SWI) has been proven to be superior to T2*-weighted imaging and also other existing magnetic resonance imaging (MRI) techniques for the detection of iron content and hemorrhage in the brain. The purpose of this study was to compare SWI with T1WI, T2WI and T2*WI in detecting splenic siderotic lesions. METHODOLOGY/PRINCIPAL FINDINGS Twenty-two patient...

Susceptibility-weighted imaging (SWI) is a new neuroimaging technique, which uses tissue magnetic susceptibility differences to generate a unique contrast, different from that of spin density, T1, T2, and T2*. In this review (the first of 2 parts), we present the technical background for SWI. We discuss the concept of gradient-echo images and how we can measure local changes in susceptibility. ...

INTRODUCTION: It has been shown that iron content measuring [1,2] and susceptibility weighted imaging (SWI) [3,4] are sensitive to the characteristics of multiple sclerosis (MS) lesions, in particular iron content. Based on the observation that SWI can detect lesions not apparent on conventional MS lesion screening protocols, it has been suggested that there may be additional clinical utility i...