Research Summary

Intermediate Fellowship research summary

Hematopoietic stem cells (HSCs), like other adult stem cells, reside in special microenvironments known as niches. Cues from the niche cells maintain an intricate balance between proliferation-inhibiting and proliferation-promoting signals that regulates stem cell maintenance versus tissue regeneration. Maintenance of hematopoetic niches is therefore very critical for HSC state and fate.

Although much attention is being paid to understand the role of niche cells in regulating the HSCs, very limited information is available about the mechanism that controls the niche cells. We are employing Drosophila as a model system to address this issue. In our previous studies we established Drosophila as a model for hematopoiesis. Drosophila lymph gland, the site of larval hematopoiesis, harbors the hematopoietic progenitor cells (Medullary Zone cells) that like their mammalian counterparts have the ability to self-renew/expand in number, and give rise to a diverse array of mature blood cells. More importantly, like mammalian HSCs the cells in the Drosophila hematopoietic precursors are also niche dependent. Using this amenable system we intend to study the signaling pathways involved in niche cell maintenance.

Drosophila Hematopoietic Organ: the Lymph Gland. The differentiating hemocytes populating the peripheral regions (Green and Blue) arise from the pluripotent stem like precursors (red), which forms the inner core of the gland.