TY  - GEN
N2  - Mild replication stress in neural stem and progenitor cells leads to the formation of recurrent DNA break clusters (RDC). Genes containing these RDCs (RDC-genes) play important roles in brain functions such as synaptogenesis and cell-cell-adhesion. Most RDC-genes do not harbor break clusters in cell types in which the RDC-genes are not being actively transcribed, but the link between transcription activity and the formation of DNA breaks in RDC-genes has not been investigated before. 

To examine whether transcription is the licensing factor for RDC formation, the promoters of two robust RDC-genes, Catenin Alpha 2 (Ctnna2) and Neurexin 1 (Nrxn1), have been independently successfully deleted in multiple ESC-NPC cell lines in vitro. In these cell lines, the transcription of Ctnna2 and Nrxn1 genes was abolished. Moreover, the number of DNA double-strand breaks was reduced in the gene-of-interest while the amount of DNA breaks in other RDC-genes remained unaffected. Additionally, also the replication timing did not change significantly when comparing the cells. Using the same unbiased genome-wide nucleotide resolution assay to detect the recurrent DNA break clusters, I was able to detect the movement of stalled/collapsed replication forks across increasing levels of replication stress and identify the observed breaks as single-ended double-strand breaks. Taking these findings together with transcription and replication directionality, it is evident that there is a bias towards head-on collision (40% more DNA double-strand breaks) versus co-directional collision of the replication fork and transcription machinery. These data fit to the hypothesized transcription/replication conflict, which is believed to play an essential role in the formation of the recurrent DNA break clusters. All things considered, my project illuminates the relationship between transcription, replication, and DNA damage in the form of double strand breaks in replication stress conditions, which can be translated to influences on the developing brain and its genome.
A1  - Ionasz, Vivien-Sandra
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/33930/
ID  - heidok33930
CY  - Heidelberg
AV  - public
Y1  - 2023///
TI  - Elucidating the role of transcription in recurrent DNA break formation
ER  -