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Nir YAKOBY

Department of Chemical Engineering
Lewis-Sigler Institute for Integrative Genomics
Princeton University
Princeton, NJ 08544
Phone: 609-258-7254
nyakoby@Princeton.EDU

EDUCATION:

Ph.D., Hebrew University, Israel.
1994, B.Sc. Hebrew University, Israel

PROFESSIONAL EXPERIENCE:

2004 to current, Post-doctoral Associate, Lewis-Sigler Institute for Integrative Genomics, Princeton University.
2000-2004 Post-doctoral Associate, BioTech Center, Rutgers University

RESEARCH INTERESTS:

Axis formation during Drosophila melanogaster egg development is controlled mainly by the joint action of two signaling molecules (morphogens), Dpp on the AP axis and Grk on the DV axis, activating the BMP and the EGF signaling pathways, respectively. Importantly, although the two morphogens amending from two discrete tissues, Dpp is secreted by the stretched cells and Grk from the cortex of the oocyte, both are perceived by the follicular epithelium, a tissue engulfing the growing oocyte.

A screen for common targets of EGFR and Dpp signaling pathways

My research raises several questions in follicular cells patterning, signal integration and cell fate determination. Specifically, I would like to assess the number of downstream targets of both the EGF and Dpp signaling pathways, to determine their spatiotemporal expression pattern and to understand the underling mechanisms by which their action is coordinated and perceived by the tissue. In order to achieve this goal, we carried out a genome wide screen for genes that are common targets of EGF and Dpp signaling in the follicular epithelium. In a follow up experiments, a large scale in situ hybridization analysis was pursued for the common genes, and in the wild type, about 20% were found to be expressed in a pattern. In order to relate their spatiotemporal pattern to the EGF and Dpp signaling pathways, we analyzed their spatial transitions in EGF and BMP perturbed tissues.

Late Dpp signaling acquires DV polarity

In addition, we found that Dpp signaling acquires a clear DV polarity from mid-oogenesis that depends on EGFR signaling. Initially, as previously reported, it has only AP polarity but we found that from mid-oogenesis the Dpp signaling pattern remains a single cell stripe on the ventral anterior and about five on the dorsal anterior. Later, the pattern splits into two separated domains on both sides of the dorsal midline. Also, we established that these transitions depend on the spatial expression of the BMP type I receptor Tkv. We demonstrated that a target gene such as the appendage-roof marker br, which is expressed in a pulse-like pattern, is regulated positively by EGFR signaling and in a negative feedback fashion by Dpp signaling. Initially, EGFR signaling induces high levels of Br at the dorsolateral patches that subsequently induces tkv, and in combination with Dpp downregulate br expression. Interestingly, several of the new patterns found in our genome wide screen presented dynamic transitions that reflected the spatiotemporal changes in the Dpp signaling.

HONORS AND AWARDS:

2007    Postdocs. poster award, Genetics Society of America, 48th Drosophila Annual Meeting.
2000    Vaadia-BARD Post-doctoral fellowship, number FI-302-2000.
1999   “Outstanding Student Lecture” at Israel Phytopathological Society 20th Convention.
1998   “Future Leadership in Orchards” from The Fruit Board of Israel and Agricultural Ministry.
1998   “Avigad and his daughter Dovrat”, from The Association of Trustees and Friends of Agricultural Research at the Volcani Center.
1996   “Yehuda Horin” from The Association of Trustees and Friends of Agricultural Research at the Volcani Center.
1995    The Fruit Board of Israel.

PUBLICATIONS

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