Similarity in early blood cell development between fruitfly and mammals


01 Nov 2016

Similarity in early blood cell development between fruitfly and mammals

Similarity in early blood cell development between fruitfly and mammals

Dr Lolitika Mandal, Intermediate Fellow

IISER Mohali

The development of blood cells (or hematopoiesis) in humans is directly linked to many diseases, including leukemia or blood cancer. Studies in last decade have demonstrated that hematopoiesis in the fruitfly Drosophila bears remarkable similarity to that in vertebrate, including humans, making the former a good model system to understand the latter.

The blood-forming organ (lymph gland) of Drosophila larvae has specialized progenitor cells that share several similarities with stem cells. Just like stem cells, these groups of cells gives rise to mature blood cells, which depends on the niche in which these cells develop and the signals/cues they receive. Our recently published work in eLife describes the signals that are required for the maintenance, quiescence and differentiation of these specialized progenitor cells into blood cells.

Here, we questioned the identity of the founder cell for these progenitors and discovered hematopoitic (blood) stem cells (or HSCs) in Drosophila. Using lineage tracing and genetic ablation they show the presence of a transient, hitherto unknown multipotent cell in the early larval stages of Drosophila. Like many other stem cells, these cells also depend on a niche for their maintenance. We identified Dpp/BMP as a niche signal for these HSCs, extending the similarity across divergent taxa.

This work demonstrates that early HSC development in fruitfly is similar to that in mammals, and brings about a paradigm shift in our understanding of hematopoiesis. This has far-reaching implications for stem cell based therapies, wherein it is imperative to know how tissue specific stem cells are specified in development. 

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Dpp dependent Hematopoietic stem cells give rise to Hh dependent blood progenitors in larval lymph gland of Drosophila. Nidhi Sharma Dey, Parvathy Ramesh, Mayank Chugh, Sudip Mandal, Lolitika Mandal. eLifeOctober 26, 2016