Steward Lab

Research Overview

The Steward lab has research interests in the Toll-Dorsal (NF-kB/Rel) pathway functioning in establishing dorsal-ventral polarity in the early Drosophila embryo, in the humoral and cellular immune response, and in hematopoiesis.  The pathway is conserved in flies and vertebrates. In mammals it controls the immune and inflammatory responses and is critical for cell growth and survival. A large number of mammalian tumors are associated with mis-regulation of the NF-kB/Rel proteins.  We are also working on histone methylation and its effect on chromatin organization in Drosophila.

Contact Information

Steward Lab
Waksman Institute
190 Frelinghuysen Road, Office 252
Piscataway, NJ 08854
United States

(848) 445-3917
steward@waksman.rutgers.edu

Selected Publications

Complete list of publications: [Pubmed]

Stem cells, Hematopoiesis, and Epigenetic Control of Chromatin Integrity in Drosophila

Zfrp8, a new gene functioning in stem cells and hematopoiesis in Drosophila

We have identified a new gene, Zfrp8 (PDCD2 in vertebrates) that regulates hematopoiesis in Drosophila. The Drosophila and human proteins are 38% identical. Several loss-of-function alleles of Zfrp8 cause enormous hyperplasia of the hematopoietic organs, the lymph glands, abnormal differentiation of immature blood cells, and severe growth delay in other tissues. The size of the lymph gland is already double that of wild type in late embryos. We have shown that the gene has a function in the regulation of the cell cycle, rather than apoptosis, as proposed by others.

We find that normal lymph gland development is more closely related to hematopoiesis in vertebrates than previously thought and hence represents an excellent model to study differentiation of blood cells. Using clonal analysis we determined that lymph glands contain stem cells at the top of a lineage ultimately giving rise to the three distinct hemocytes. With the same approach we showed that Zfrp8/PDCD2 is essential for the maintenance of the stem cells. We have also established that Zfrp8/PDCD2 function is required in all stem cells investigated so far, namely ovary germline and somatic stem cells, as well as gut stem cells.

Zfrp8 function in germline
Zfrp8 function in germline

Current Lab Members

Principal Investigator
  • Dr. Ruth Steward
    Dr. Ruth Steward

    steward@waksman.rutgers.edu

    Dr. Ruth Steward is Principal Investigator at the Waksman Institute of Microbiology and a Professor of Honors Molecular Biology and Biochemistry courses at Rutgers University — New Brunswick.

    Dr. Steward has research interests in the Toll-Dorsal (NF-kB/Rel) pathway functioning in establishing dorsal-ventral polarity in the early Drosophila embryo, in the humoral and cellular immune response, and in hematopoiesis.  The pathway is conserved in flies and vertebrates. In mammals it controls the immune and inflammatory responses and is critical for cell growth and survival. A large number of mammalian tumors are associated with mis-regulation of the NF-kB/Rel proteins.  She is also working on histone methylation and its effect on chromatin organization in Drosophila.

Graduate Students
  • Waksman Person
    Hiep Tran