Ovarian Club X and CoGEN in Asia

SpeakerS

Sunney Xiaoliang XIE (USA)

Xiaoliang Sunney Xie received a B.S. from Peking University (1984), and Ph.D. from the University of California San Diego (1990), did a postdoctorate at University of Chicago. In 1992, joined Pacific Northwest National Laboratory, where he became Chief Scientist. In 1999, he was appointed Professor of Chemistry at Harvard University, the first full professor at Harvard from the People's Republic of China since China's reform in 1978. He is currently the Mallinckrodt Professor of Chemistry and Chemical Biology at Harvard, the Cheung Kong Visiting Professor at Peking University, Director of Beijing Advanced Innovation Center for Genomics and Director of Biodynamics Optical Imaging Center (BIOPIC), both at Peking University.

Xie is among the first doing fluorescence studies of single-molecules at room temperature in early 1990s. He has made major contributions to the emergence of single-molecule biophysical chemistry and its applications to biology and medicine.

His honors include Albany Prize in Medicine and Biomedical Research, U. S. Department of Energy Lawrence Award, Biophysical Society’s Founders Award, National Institute of Health Director’s Pioneer Award, Sackler Prize for Physical Sciences, American Chemical Society’s Peter Debye Award, fellow of the American Academy of Arts and Sciences, member of the National Academies of Sciences and Medicine.

Abstract

Single Cell Whole Genome Amplification Technologies and the Future of Chromosome Screening

Single-cell whole-genome amplification is critical for preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). However, current whole-genome amplification (WGA) methods are limited by low accuracy of copy- number variation (CNV) detection and low amplification fidelity. We have developed a much improved single-cell WGA method, Linear Amplification via Transposon Insertion (LIANTI), which outperforms existing methods, enabling micro-CNV detection with kilobase resolution. This makes it possible to screen embryos with micro deletions in the range of 100k-10M bases, some of which are known to cause genetic disorders.

Balanced Translocations (BT) and Robertsonian Translocations (RT) are among the most common chromosomal diseases that cause infertility and birth defects. Preimplantation genetic diagnosis (PGD) of in vitro fertilized (IVF) embryos enables embryo selection with balanced chromosomal ploidy, but is normally unable to resolve the translocation carrier state. We have developed a method that enables the selection of translocation-free embryos from patients carrying chromosomal translocations. Preimplantation genetic screening (PGS) has been widely used to select in vitro fertilized embryos free of chromosomal abnormalities and to improve the clinical outcome of in vitro fertilization (IVF). A disadvantage of PGS is that it requires biopsy of the preimplantation human embryo, which can limit the clinical applicability of PGS due to the invasiveness and complexity of the process. We have developed a noninvasive chromosome screening (NICS) method based on sequencing the genomic DNA secreted into the culture medium from the human blastocyst. The NICS method offers the potential of much wider chromosome screening applicability in clinical IVF, due to its high accuracy and noninvasiveness.