Poster (download) Kitill Ustyantsev1, Valeriya Vavilova2, Mikhail Biryukov3, Eugene Berezikov41Sector of molecular-genetic mechanisms of regeneration ICG SB RAS Novosibirsk, Russia, firstname.lastname@example.orgSector of molecular-genetic mechanisms of regeneration ICG SB RAS Novosibirsk, Russia, email@example.comInterinstitutional laboratory of molecular paleogenetics and paleogenomics ICG SB RAS Novosibirsk, Russia, firstname.lastname@example.orgSector of molecular-genetic mechanisms of regeneration ICG SB RAS Novosibirsk, Russia European Research Institute for the Biology of Ageing Groningen, The Netherlands, email@example.com В Free-living flatworm Macrostomum lignano is a novel model organism that provides a genetically tractable experimental system to specifically study the interplay between regulation of regeneration and cancer. Here, we tested two chemical carcinogens (MMS and CsA) and short wavelength ultraviolet irradiation (UVC) in M. lignano in order to identify genes and molecular pathways underlying carcinogenic response in this flatworms. For the first time, sensitivity of M. lignano to hard UV was evaluated, and it was shown that the worm can easily tolerate sterilization-level doses of higher than 100 mJ/cm2. Using differential gene expression analysis based on generated RNA-Seq data, common and individual patterns of M. lignano transcriptional response to the induced carcinogenesis by the tested stimuli were determined. This allowed us to select promising candidate genes for functional studies using RNAi knock-down screens and for determination of their role in stem cells regulation under regeneration and homeostasis in M. lignano.
Poster (download) Kira Zadesenets1, Nikita Ershov2, Dmitry Oshchepkov3, Eugene Berezikov4, Lukas SchГ¤rer5, Nikolay B. Rubtsov61ICG SB RAS, firstname.lastname@example.orgICG SB RAS, email@example.comICG SB RAS, firstname.lastname@example.orgERIBA, Groningen, The Netherlands, email@example.comEvolutionary Biology, Zoological Institute, University of Basel, Basel, Switzerland, firstname.lastname@example.orgICG SB RAS, email@example.com Whole genome duplication (WGD) is a large-scale evolutionary transformation that took place in genome evolution in many taxa of existing animal species. However, the mechanisms underlying the early stages of genome evolution after a WGD event in animals has remained unclear. The study of genome organization of neopolyploid species may shed light on the processes of genome reorganization leading to its re-diploidization after a recent round of WGD. Earlier we uncovered a group of free-living flatworms in which genomes have likely undergone a recent WGD. We found out that karyotype instability was linked to hidden polyploidy in both species M. lignano (2n = 8) and its sibling species M. janickei (2n = 10). Additional studies of other species of the genus Macrostomum revealed a new species (further called M. mirumnovem) with a highly unstable karyotype. The detailed cytogenetic analyses using a set of different DNA probes (microdissected region- and chromosome specific DNA probes, DNA repeats, unique DNA fragments) revealed the peculiarities of karyotype and genome organization in three Macrostomum species with unstable karyotypes. Similar to M. lignano and M. janickei, our findings suggest that M. mirumnovem arose via whole genome duplication (WGD) followed by considerable reshuffling of its chromosomes. The combined approach allowed us to explore the peculiarity of the M. lignano genome organization, the strategy included bioinformatics analysis of the existed genome assemblies of M. lignano and NGS data for its separate chromosomes. Based on the obtained results, we suggest possible evolutionary scenarios for the emergence and reorganization of the karyotypes and genomes of the post-WGD Macrostomum species.