Discovered in 2006 by Dr. Eran Segal of the Computer Science and Applied Mathematics Department and his group, this code appears at intervals of 10 base pairs (the “letters” of the genetic code) in certain DNA sequences. It facilitates the bending of segments of about 150 base pairs into protein-DNA complexes called nucleosomes – neat, spherical beads strung on the DNA strand.
Two new studies by his group, which appeared recently in Nature and Nature Genetics, provide evidence that this code is universal, from yeast to humans, and that it helps to shape those organisms and streamline the process of gene expression. The group, including research students Noam Kaplan and Yair Field, along with Yaniv Lubling, carried out this research in collaboration with the groups of Jonathan Widom at Northwestern University in Evanston, Illinois, Jason Lieb at the University of North Carolina in Chapel Hill, North Carolina, and Tim Hughes at the University of Toronto. “In the 2006 study, we worked with several hundred DNA sequences. Today, with new advances in technology, we can test something like 10 million,” says Segal.
In the second study, Segal and his team revisited previous Institute research from the group of Prof. Naama Barkai of the Molecular Genetics Department. They discovered that differences in gene expression are tied to changes in the placement of nucleosomes, which, in turn, might constitute a previously unidentified genetic mechanism for achieving change across evolution.
Dr. Eran Segal’s research is supported by the Chais Family Fellows Program for New Scientists; the Hana and Julius Rosen Fund; and the Cecil and Hilda Lewis Charitable Trust.
Life-Giving Research
In 2006, Prof. Nava Dekel of the Biological Regulation Department, together with doctors in the IVF unit of Kaplan Medical Center, made the surprising discovery that performing a uterine biopsy – causing a slight injury to the lining of the uterus – just before a woman undergoes in vitro fertilization (IVF) doubles the chances of a successful pregnancy. The injury apparently provokes a response that makes the uterus more receptive to the embryo's implantation.
The next year, Dekel was in Toronto, Canada, giving a lecture in the framework of the Weizmann Women and Science series, organized by Weizmann Canada. That lecture was reported in a local Jewish newspaper, where it caught the attention of Howard and Roslyn Kaman. After years of unsuccessful fertility treatments, failed IVF and miscarriages, the couple gained new hope. They contacted Dekel, and she referred them to Drs. Amichai Barash and Irit Granot, who had participated in the original research along with Drs. Yael Kalma and Yulia Gnainsky of the Weizmann Institute.
The Rehovot doctors provided a detailed description of the procedure, which was then performed in a fertility clinic in Toronto. The result: A healthy baby girl, Hannah Esther Angel Kaman, was born this past October.
Prof. Nava Dekel's research is supported by the Dwek Family Biomedical Research Fund; the Kirk Center for Childhood Cancer and Immunological Disorders; and the Dr. Pearl H. Levine Foundation for Research in the Neurosciences. Prof. Dekel is the incumbent of the Philip M. Klutznick Professorial Chair of Developmental Biology.