You are invited to attend this virtual seminar hosted by the Institute of Molecular and Cell Biology:
Date: Wednesday, 6 March 2024
Time: 10.00AM – 11.00AM
Zoom: https://zoom.us/j/97930378409?pwd=S1R5TXpadTZEUnlqbStmMDFySysvdz09 Meeting ID: 979 3037 8409
Passcode: 899434
Speaker: Dr. Kehui Xiang, Whitehead Institute
Host: Dr. Leslie Beh, IMCB
Control of Poly(A)-tail Length and Translational Efficiency in Vertebrate Oocytes and Early Embryos
Abstract
During oocyte maturation and early embryogenesis, changes in mRNA poly(A)-tail lengths strongly influence translation, but how these tail-length changes are orchestrated has been unclear. Here, we performed tail-length and translational profiling of mRNA reporter libraries (each with millions of 3ʹ-UTR sequence variants) in frog oocytes and embryos, and fish embryos. Contrasting to previously proposed cytoplasmic polyadenylation elements, we found that a shorter element, UUUUA, together with the polyadenylation signal, specifies cytoplasmic polyadenylation, and identified contextual features that modulate the activity of both elements. In maturing oocytes, this tail lengthening occurs against a backdrop of global deadenylation and the action of C-rich elements that specify tail-length-independent translational repression. In embryos, cytoplasmic polyadenylation becomes more permissive, and additional elements specify waves of stage-specific deadenylation. Together, these findings largely explain the complex tapestry of tail-length changes observed in early frog and fish development, and neural network models indicate that many findings extend to humans, with implications for fertility and health.
Biography
Dr. Xiang earned his bachelor’s degree in Mathematics and Physics from Tsinghua University, China and completed his Ph.D. in Biological Sciences at Columbia University, USA. Presently, he is working in Dr. David Bartel’s lab as a postdoctoral associate at the Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, USA. Dr. Xiang's research has been centered on RNA biology and post-transcriptional gene regulation during vertebrate early development. Employing a multidisciplinary approach, he integrates high-throughput system methodologies, RNA and protein biochemistry, functional genomic screens, and machine learning to unravel gene-regulatory mechanisms governing developmental transitions. His contributions have been published in Nature, eLife, Developmental Cell, and many other journals. Dr. Xiang has received Chinese Government Award for outstanding self-financed students abroad and CRI Irvington Postdoctoral Fellowship from Cancer Research Institute.
ALL ARE WELCOME (No registration required)
