Complete mitochondrial genomes of representatives of two endemic sculpin families (Perciformes: Cottoidei) from Baikal - the world's largest and deepest lake.

In this study, five new mitogenomes from four endemic Lake Baikal sculpins were determined: Cottocomephorus grewingkii (Dybowski, 1874) (GB#MW732165), Cottocomephorus inermis (Yakovlev, 1890) (GB#MW732163), and Paracottus knerii (Dybowski, 1874) (GB#MW732164) (Family Cottocomephoridae - Bighead sculpins), and from two specimens of Procottus major Taliev, 1949 (GB##MW732166, MW732167) from Family Abyssocottidae (Deep-water sculpins). Together with recently published mitogenomes of Baikal Oilfishes (Sandel et al. 2017), the first mitogenome-based phylogenetic tree for all three endemic Baikal sculpin families is presented. Complete mitogenome phylogeny supports the monophyletic origin of the lake Baikal sculpins species flock, but does not support the monophyly of the family Cottocomephoridae (Bighead sculpins).

Uncovering molecular mechanisms of regulated cell death in the naked mole rat.

The naked mole rat (NMR), Heterocephalus glaber, is the longest-living rodent species, and is extraordinarily resistant to cancer and aging-related diseases. The molecular basis for these unique phenotypic traits of the NMR is under extensive research. However, the role of regulated cell death (RCD) in the longevity and the protection from cancer in the NMR is still largely unknown. RCD is a mechanism restricting the proliferation of damaged or premalignant cells, which counteracts aging and oncotransformation. In this study, DNA damage-induced cell death in NMR fibroblasts was investigated in comparison to RCD in fibroblasts from Mus musculus. The effects of methyl methanesulfonate, 5-fluorouracil, and etoposide in both cell types were examined using contemporary cell death analyses. Skin fibroblasts from Heterocephalus glaber were found to be more resistant to the action of DNA damaging agents compared to fibroblasts from Mus musculus. Strikingly, our results revealed that NMR cells also exhibit a limited apoptotic response and seem to undergo regulated necrosis. Taken together, this study provides new insights into the mechanisms of cell death in NMR expanding our understanding of longevity, and it paves the way towards the development of innovative therapeutic approaches.

Simulation of high-resolution x-ray zone plates.

A full-wave approach to quantitative characterization of x-ray zone plate lenses is proposed. Distributed focusing efficiency eta(z) of a multifocus optical element is defined as the energy flux through the Airy disk of a reference perfect lens with variable focal length z. Maxima of this function characterize diffraction efficiencies and spatial resolution of the zone plate foci. The parabolic wave equation is used to take into account diffraction effects inside the optical element. Rough and fuzzy interface models are introduced to describe realistic zone profiles. Numerical simulation reveals the limited capability of zone width reduction to improve the zone plate imaging performance. The possibilities of second-order focus enhancement by optimization of the zone plate thickness, line-to-space ratio, and zone tilt are studied numerically.