DNA repair is an active cellular process to respond to constant DNA damage caused by metabolic processes and environmental factors. Since the outcome of DNA damage is generally adverse and long term effects may contribute to oncogenesis, cells have developed a variety of DNA repair mechanisms, which operate depending on the type of DNA damage inflicted. At least 15 Fanconi anemia (FA) proteins interact in a common pathway involved in homologous recombination. Inherited homozygous mutations in any of these FA genes cause a rare disease, Fanconi anemia, characterized by congenit al abnormalities, progressive bone-marrow failure and cancer susceptibility. Heterozygous germline FA mutations predispose to various types of cancer. In addition, somatic FA mutations ha ve been identified in diverse cancer types. Evidence exists that cells deficient in the FA pathway become dependent on alternative pathways for survival. Additional inhibition of such alternative pathways is thus expected to result in cell death, creating a relationship of synthetic lethality. Identifying these relationships can reveal yet unknown mechanisms of DNA repair and new targets for therapy., T. Hucl, E. Gallmeier., and Obsahuje bibliografii a bibliografické odkazy
Torotrogla merulae Skoracki, Dabert et Ehrnsberger, 2000 and T. rubeculi Skoracki, 2004 have been considered as distinct steno- and monoxenous quill mite species (Acari: Prostigmata: Syringophilidae) parasitizing the thrushes of the genus Turdus Linnaeus and the European robin Erithacus rubecula (Linnaeus), respectively. Morphological and molecular studies on the taxonomical status of these two species provided contradictory results. Well defined differences in morphology were not supported by substantial genetic distance in nucleotide sequences of the DNA barcode (mitochondrial cytochrome c oxidase subunit I, COI, and D2 domain of the nuclear 28S rRNA gene), by the topology of the phylogenetic trees (neighbor-joining, maximum parsimony, maximum likelihood) and the network analyses of the COI haplotype genealogy (median-joining, statistical parsimony) that reveal rubeculi populations nested within merulae haplotypes. Since detected differences between T. merulae and T. rubeculi populations (1.6-2.4% for COI and 0.1% for D2) are comparable to the intraspecific level observed in majority of currently recognized European Torotrogla species and are much lower than the interspecific distances observed in the genus, we postulate their conspecificity. Because main morphological distinctions concern the structures used for feeding, we hypothesize that they are the result of phenotypic plasticity evoked by specific and different environmental conditions prevailing on the host bodies (thickness of the feather quill wall).