RT Journal Article SR Electronic T1 Transcription activity contributes to the firing of non-constitutive origins in Trypanosoma brucei JF bioRxiv FD Cold Spring Harbor Laboratory SP 398016 DO 10.1101/398016 A1 Marcelo S. da Silva A1 Gustavo R. Cayres-Silva A1 Marcela O. Vitarelli A1 Paula A. Marin A1 Priscila M. Hiraiwa A1 Christiane B. Araújo A1 Andrea R. Ávila A1 Marcelo S. Reis A1 Maria Carolina Elias YR 2018 UL http://biorxiv.org/content/early/2018/09/03/398016.abstract AB The cosynthesis of DNA and RNA potentially generates conflicts between replication and transcription, which can lead to genomic instability. In trypanosomatids, eukaryotic parasites that perform polycistronic transcription, this phenomenon and its consequences have not yet been investigated. Here, using equations and computational analysis we demonstrated that the number of constitutive origins mapped in the Trypanosoma brucei genome is close to the minimum required to complete replication within S phase duration. However, taking into account the location of these origins in the genome, the replication in due time becomes virtually impossible, making it necessary to activate non-constitutive origins. Moreover, computational and biological assays pointed to transcription being responsible for activating non-constitutive origins. Together, our results suggest that transcription action through conflicts with replication contributes to the firing of non-constitutive origins, maintaining the robustness of S phase duration. The usage of this entire pool of origins seems to be of paramount importance for the survival of this parasite that infects million people around the world since it contributes to the maintenance of the replication of its DNA.