Using vertebrate model to study diseases: Indian scientists discover hematopoietic stem cells in fruit fly

Kolkata: For the first time, Indian researchers have hunted down the elusive hematopoietic stem cells in fruit flies. Hematopoietic stem cells are the stem cells that give rise to all the other blood cells and are generally found in the peripheral blood and the bone marrow.

They said the discovery in fruit fly has far-reaching implications for stem cell-based therapies for humans.

"We have unveiled and reported affirmatively, the existence of true hematopoietic stem cells (HSCs) in Drosophila (fruit fly), which have long eluded scientists," Lolitika Mandal from the Developmental Genetics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Mohali, told IANS in an email.

The research thus paves the way for understanding mechanisms of many diseases in humans linked to the development of blood cells.

The discovery in fruit fly (invertebrate) model-which shares several similarities with humans at the molecular level-offers a platform to study and answer several questions pertinent to vertebrate blood development, the researchers said.

"For example, one of the aspects that has drawn much attention is to understand the mechanisms regulating self-renewal of early HSCs. Understanding the mechanism will help us in developing methods for early HSCs expansion important for regenerative medicine," said Mandal, a Wellcome Trust/DBT India Alliance Intermediate Fellow.

Drosophila hematopoiesis (the process by which blood cells are formed) mirrors striking resemblance with that of vertebrates, both at the level of signalling molecules and the phase of development.

But why can not we use the vertebrate model?

"These early HSCs appear 11.5 days post conception in mouse and approximately 32-33 post-ovulatory days in human. Thus, due to technical limitations and rarity of vertebrate early HSCs we still have little understanding about the nature of division that the cells undergo or the complex transcriptional network that controls the HSC fate," Mandal explained.

So, the fruit fly model can plug in the gap "to identify and elucidate not only normal development but also several uncharacterised early pathological events linked with embryonic HSC related disorders."

Leukemia, Amyeloproliferative or myledisplastic syndromes and several types of anaemia can be associated with blood development, Mandal added.

The outcome of this study holds the promise of opening new avenues to better understand developmental hematopoiesis, Mandal said.

"This has a far-reaching implication spilling into stem cell based therapies, wherein it is pertinent to know how tissue specific stem cells are specified in development," she added.

The co-authors of the paper are Nidhi Sharma Dey, Parvathy Ramesh, Mayank Chugh, Sudip Mandal.

The research has been published recently in the journal eLife.