Functional analyses of homoeologous pericentromeric cohesion protective genes TaSGO1s during meiosis in Triticum aestivum

The precise separation of chromosomes during meiosis is critical for maintaining genetic stability, a process intricately orchestrated by Shugoshin (SGO) proteins. SGO plays a pivotal role in protecting the centromere cohesion protein, preventing its premature dissociation during metaphase in meiosis I. This safeguarding function persists until metaphase in meiosis II, thereby preventing early sister chromatid separation. However, the function of SGO1 in wheat (Triticum aestivum) has not been thoroughly investigated. In this study, we characterized the homoeologous copies of the SGO1 protein in hexaploid bread wheat. We found that the sequence identity among the three homoeologous TaSGO1 genes exceeds 93%, demonstrating conservation with their diploid and tetraploid ancestral SGO1 homologs. These genes also share a common C-terminal 'sgo' conserved domain. Heterologous complementation experiments in Arabidopsis demonstrated that all three TaSGO1 homoeologs can functionally substitute for AtSGO1 in protecting centromeric cohesion during meiosis, suggesting that they possess the conserved molecular activity required for this function in wheat. All three TaSGO1 homoeologs partially restored fertility and normal chromosome segregation in the Arabidopsis sgo1 mutant, demonstrating conserved function in protecting centromeric cohesion during meiosis. In summary, this study offers significant insights into the homoeologous copies of TaSGO1 in wheat, highlighting their integral role in the complex process of meiotic chromosome separation.