Role for hACF1 in the G2/M damage checkpoint.

Active chromatin remodelling is integral to the DNA damage response in eukaryotes, as damage sensors, signalling molecules and repair enzymes gain access to lesions. A variety of nucleosome remodelling complexes is known to promote different stages of DNA repair. The nucleosome sliding factors CHRAC/ACF of Drosophila are involved in chromatin organization during development. Involvement of corresponding hACF1-containing mammalian nucleosome sliding factors in replication, transcription and very recently also non-homologous end-joining of DNA breaks have been suggested. We now found that hACF1-containing factors are more generally involved in the DNA damage response. hACF1 depletion increases apoptosis, sensitivity to radiation and compromises the G2/M arrest that is activated in response to UV- and X-rays. In the absence of hACF1, γH2AX and CHK2ph signals are diminished. hACF1 and its ATPase partner SNF2H rapidly accumulate at sites of laser-induced DNA damage. hACF1 is also required for a tight checkpoint that is induced upon replication fork collapse. ACF1-depleted cells that are challenged with aphidicolin enter mitosis despite persistence of lesions and accumulate breaks in metaphase chromosomes. hACF1-containing remodellers emerge as global facilitators of the cellular response to a variety of different types of DNA damage.

The 100-year old collection of wax moulages at the Department of Dermatology of the University of Bonn.

The tradition of wax models in Dermatology, also named moulages, is about 200 years old. Dermatology departments all over the world created wax moulages collections to teach students and doctors as well as to document research. In 1910 Erich Hoffmann, who discovered Spirochaeta pallida together with Fritz Schaudinn, became head of the department of dermatology in Bonn. He founded one of the largest moulage collections in Germany. This almost unknown collection consists of more than 1,000 delicate and well conserved wax models. Two excellent wax moulage makers, Auguste Kaltschmidt and Hermann Hessling, produced most of these masterpieces between 1913 and 1937. Until recently, A. Kaltschmidt has only been known to have worked as moulage maker in Rostock, while the biographic details of both her and H. Hessling remained obscure. This paper aims (i) to outline Erich Hoffmann's role for and his contribution to the moulage collection and (ii) to give the first biographic details about the two outstanding dermatologic moulage makers of the collection of Bonn.