Context-specific functions of Notch in Drosophila blood cell progenitors

Abstract

Notch signaling regulates differently distinct populations of blood cell progenitors of the Drosophila larval hematopoietic organ..

Integrated Transcriptome and Proteome Analyses Reveal the Regulatory Role of miR-146a in Human Limbal Epithelium via Notch Signaling

“…It is well established that Notch signaling plays a pivotal role in cellular communication, regulating stem cell maintenance, proliferation, and differentiation during embryonic development, as well as tissue homeostasis and stem cell self-renewal in multiple adult organ systems [ 55 , 56 , 57 ]. The role of Notch in controlling stem cell population and differentiation decisions is considered to be cell context specific [ 55 , 58 , 59 ]. There have been some conflicting reports regarding the regulatory role of Notch signaling in the corneal epithelium.…”

Regulation of Drosophila Hematopoiesis in Lymph Gland: From a Developmental Signaling Point of View

“…Recently, different subpopulations of Dome+ progenitors in the MZ were precisely defined with distinct markers. The most central progenitors that express Tep4 or collier ( col , also known as knot ) are defined as the Core progenitors [ 35 ], and the neighboring progenitors that lack Tep4 or col expression are named Distal progenitors [ 36 ].…”

“…However, the requirement of PSC cells as well as the role of col in the PSC for progenitor maintenance have been challenged by recent studies [ 35 , 43 ], in which the genetic ablation of the PSC did not cause a loss of prohemocyte population. Later, additional studies repeatedly demonstrated that the signaling molecules sent out from the PSC, such as Hh and Ser, are indeed required to restrain hemocyte differentiation and maintain the MZ progenitors in an undifferentiated state [ 35 , 36 , 44 ], further supporting the critical role of the PSC as a hematopoietic niche. However, the role of col in the PSC has to be reconsidered.…”

“…In contrast to PSC-expressing col , the col in the MZ has been revealed to act as an intrinsic regulator that controls the maintenance of prohemocytes, as knocking down col expression in the MZ led to a significant loss of prohemocytes and massive hemocyte differentiation [ 35 , 43 ], resembling the phenotype of a col mutant. In addition, it has been found that the MZ prohemocyte population is heterogeneous, containing both Col-positive and Col-negative cells [ 36 , 44 ]. The number of the Col-negative prohemocyte subpopulation is significantly reduced after PSC ablation, whereas the number of Col-positive prohemocytes is not affected by PSC manipulation [ 44 ].…”

“…The best characterized function of Notch signaling during larval hematopoiesis is to determine the crystal cell fate. Notch expression is ubiquitous throughout the third-instar lymph gland primary lobe [ 36 , 49 ]. Loss-of-function mutations in Notch result in a drastically decreased number of crystal cells [ 24 , 49 , 50 ], suggesting that Notch signaling is required for crystal cell differentiation.…”