BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Talks.cam//talks.cam.ac.uk// X-WR-CALNAME:Talks.cam BEGIN:VEVENT SUMMARY:Duy-Chi Trinh-How do flowers close themselves: the story from Arab idopsis\; Liyuan Sui-Cell tilting: A novel mechanism driving three-dimensi onal epithelial morphogenesis - Duy-Chi Trinh-ENS de Lyon\, France\; Univ ersity of Science and Technology of Hanoi\, Vietnam &\; Liyuan Sui-Post doc from Christian Dahmann’s Lab School of Science\, Technische Universi tät Dresden DTSTART:20241028T143000Z DTEND:20241028T153000Z UID:TALK220213@talks.cam.ac.uk CONTACT:Jia CHEN DESCRIPTION:How do flowers close themselves: the story from Arabidopsis \ n\nDr Duy-Chi Trinh \n\nAffiliations: ENS de Lyon\, France\; University o f Science and Technology of Hanoi\, Vietnam \n\nAbstract: Plant reproduct ion is crucial for plants as well as for humans\, as it provides us with f lowers\, fruits and seeds. The reproductive organs (stamens and pistils) a re generally fragile and need to be well protected during their developmen t. The flower bud can close to protect themselves in several ways\, for ex ample\, by twisting or simply inward curving of sepals or petals. How the floral bud becomes sealed is largely unknown. In this study\, we attempt t o understand the mechanics of flower closure using the plant Arabidopsis t haliana as the model. In Arabidopsis\, the flower is closed thanks to the inward curving of the four sepals. In the outermost sepal\, we identified a small region at the sepal tip that is markedly curved inward early on an d remains curved even after anthesis. Through modelling and quantitative g rowth analysis\, we find that this hook emerges from growth arrest at the tip at a stage when cortical microtubules align with growth-derived tensil e stress. Depolymerizing microtubules specifically at young sepal tips hin dered hook formation and resulted in open floral buds. Mutants with defect ive growth patterns at the tip failed to curve inwards\, whereas mutants w ith enhanced alignment of cortical microtubules at the tip exhibited a str onger hook. We propose that floral buds are locked due to a stress-derived growth arrest event curving the sepal tip and forming a rigid hook early on during flower development. \n\n\nCell tilting: A novel mechanism drivin g three-dimensional epithelial morphogenesis \n\nDr. Liyuan Sui \nAbstrac t\nDynamic changes in three-dimensional cell shape and arrangement are cru cial for tissue form and function. However\, most studies on cell behavior have primarily focused on the apical surface of tissues. Investigating ti ssue morphogenesis in three dimensions within living tissue presents signi ficant challenges. In our latest research\, we explore the developing Dros ophila eye\, where the progression of an epithelial fold\, known as the mo rphogenetic furrow\, drives photoreceptor differentiation. This process in volves a series of three-dimensional changes in cell shape and arrangement as the morphogenetic furrow advances from the posterior to the anterior o f the eye-antennal disc. \n\nIn this study\, we employed live imaging of e x vivo cultured eye-antennal discs and quantitative image analysis to demo nstrate how the morphogenetic furrow progresses through a series of comple x three-dimensional changes in cell shape and arrangement. Ultimately\, we identified a cellular tilting mechanism that drives columnar cells to rep osition within the epithelium to promote morphogenetic furrow progression and cell differentiation. Given the conservation of morphogenetic processe s\, we anticipate that similar cell-tilting mechanisms occur in other tiss ues and organisms. \n\nJoin the Zoom with the link: \nhttps://cam-ac-uk.zo om.us/j/87503254733\nMeeting ID: 875 0325 4733 LOCATION:Online END:VEVENT END:VCALENDAR