PT - JOURNAL ARTICLE AU - Mota, Ignacio Prusén AU - Galova, Marta AU - Schleiffer, Alexander AU - Nguyen, Tan-Trung AU - Kovacikova, Ines AU - Nishiyama, Tomoko AU - Gregan, Juraj AU - Peters, Jan-Michael AU - Schlögelhofer, Peter TI - SORORIN is an evolutionary conserved antagonist of WAPL AID - 10.1101/2022.10.24.513534 DP - 2022 Jan 01 TA - bioRxiv PG - 2022.10.24.513534 4099 - http://biorxiv.org/content/early/2022/10/24/2022.10.24.513534.short 4100 - http://biorxiv.org/content/early/2022/10/24/2022.10.24.513534.full AB - Cohesin mediates sister chromatid cohesion to enable chromosome segregation and DNA damage repair. To perform these functions, cohesin needs to be protected from WAPL, which otherwise releases cohesin from DNA. It has been proposed that cohesin is protected from WAPL by SORORIN. However, in vivo evidence for this antagonism is missing and SORORIN is only known to exist in vertebrates and insects. It is therefore unknown how important and widespread SORORIN’s functions are. Here we report the identification of SORORIN orthologs in Schizosaccharomyces pombe (Sor1) and Arabidopsis thaliana (AtSORORIN). sor1Δ mutants display cohesion defects, which are partially alleviated by wpl1Δ. Atsororin mutant plants display dwarfism, tissue specific cohesion defects and chromosome mis-segregation. Furthermore, Atsororin mutant plants are sterile and separate sister chromatids prematurely at anaphase I. The somatic, but not the meiotic deficiencies can be alleviated by loss of WAPL. These results provide in vivo evidence for SORORIN antagonizing WAPL, reveal that SORORIN is present in organisms beyond the animal kingdom and indicate that it has acquired tissue specific functions in plants.Competing Interest StatementThe authors have declared no competing interest.