Discharge in a Subthreshold Microwave Beam as an Unusual Type of Ionization Wave

Plasma Physics Reports - Ionization−overheating instability of a non-self-sustained discharge in air in a subthreshold microwave field creates a self-sustained discharge with a fine cellular...     

DNA polymerase η mutational signatures are found in a variety of different types of cancer

DNA polymerase (pol) η is a specialized error-prone polymerase with at least two quite different and contrasting cellular roles: to mitigate the genetic consequences of solar UV irradiation, and promote somatic hypermutation in the variable regions of immunoglobulin genes. Misregulation and mistargeting of pol η can compromise genome integrity. We explored whether the mutational signature of pol η could be found in datasets of human somatic mutations derived from normal and cancer cells. A substantial excess of single and tandem somatic mutations within known pol η mutable motifs was noted in skin cancer as well as in many other types of human cancer, suggesting that somatic mutations in A:T bases generated by DNA polymerase η are a common feature of tumorigenesis. Another peculiarity of pol ηmutational signatures, mutations in YCG motifs, led us to speculate that error-prone DNA synthesis opposite methylated CpG dinucleotides by misregulated pol η in tumors might constitute an additional mechanism of cytosine demethylation in this hypermutable dinucleotide.     

An underground burst of diversity – a new look at the phylogeny and taxonomy of the genus Talpa Linnaeus, 1758 (Mammalia: Talpidae) as revealed by nuclear and mitochondrial genes

Using both nuclear and mitochondrial sequences, we demonstrate high genetic differentiation in the genus Talpa and confirm the existence of cryptic species in the Caucasus and Anatolia, namely, T. talyschensis Vereschagin, 1945, T. ognevi Stroganov, 1948, and Talpa ex gr. levantis. Our data support four clades in the genus Talpa that showed strong geographical associations. The ‘europaea’ group includes six species from the western portion of the genus' range (T. europaea, T. occidentalis, T. romana, T. caeca, T. stankovici, and T. levantis s.l.); another three groups are distributed further east: the ‘caucasica’ group (Caucasus), the ‘davidiana’ group (eastern Anatolia and Elburz) and T. altaica (Siberia). The phylogenetic position of T. davidiana was highlighted for the first time. The order of basal branching remains controversial, which can be attributed to rapid diversification events. The molecular time estimates based on nuclear concatenation estimated the basal divergence of the crown Talpa during the latest Miocene. A putative scenario of Talpa radiation and issues of species delimitation are discussed. © 2015 The Linnean Society of London