Yanas Tigan was a Trill female who lived during the 24th century. She was the mother of Janel Tigan, Ezri Dax and Norvo Tigan. Tigan owned and operated a pergium mine on the planet Sappora VII that she established herself. Yanas and her husband were estranged.
Nearly, six months Ezri asked Yanas to use her influence to help find Miles O'Brien, who had gone missing on New Sydney. Yanas was furious that Janel and Norvo had turned to the Orion Syndicate when the company was in financial difficulty. After it was revealed Norvo had killed Morica Bilby, Yanas wondered if she was responsible for his actions. (DS9 episode: "Prodigal Daughter")
In 2376, Ezri experienced a different reality, due to the cathedral artifact, where she had left Starfleet and returned home. In this reality, her mother was pleased that she had done so. (DS9 - Mission Gamma novel: Cathedral)