Taken together, these observations are consistent with functionally and argue that in the developing pancreas, a spatially restricted positioning and/or activation of M2 macrophages must be present to allow for their anti-proliferative effects to take place on progenitors delaminating from the ductal compartment, but not on their islet cell progeny. Collectively, our studies uncover a novel role of Dasatinib macrophages in their M2 state of activation as positive regulators of pancreatic progenitors recruitment and differentiation toward the islet cell lineage, as well as modulators of islet cell cycle progression. Although the molecular effectors of these macrophage-driven functions remain to be identified, our findings point to a cellular mechanism that could be exploited in pancreatic tissue regeneration. Hence, in light of these results it may be important to test whether brakes on islet regenerative responses in vivo following injury and/or degeneration may be modulated by targeting the anti-proliferative effects of M2 macrophages. In addition, the functional properties of macrophages identified here may be harnessed for the development of improved protocols of in vitro directed differentiation of islet cells from either ESC or iPSC preparations. Hence, macrophages with distinct states of functional activation may be exploited to promote either expansion or differentiation of stem cell/progenitor cell populations. The grains of rice grow on the spikelets, which can be classified as SS or IS according to their location on a branch and the time of flowering. In general, SS are on the apical primary branches, while IS on the proximal secondary branches on a rice plant. By comparison, SS flower earlier and fill faster with larger and heavier grains than IS. The poor grain-filling of IS on rice cultivars, especially for the ‘‘super’’ EX 527 varieties developed recently that bear numerous spikelets per panicle, has become a subject for study, as it not only negatively affects the final yield but also the milling and quality of the rice. The grain-filling of rice is largely a process of starch accumulation, since the starch contributes 90% of the dry weight of an unpolished mature grain. However, it has been reported that the carbohydrates may not be the only limiting factor. Low activities of the enzymes that convert sucrose to starch, such as sucrose synthase, adenosine diphosphateglucose pyrophosphorylase, starch synthase, and starch branching enzyme, might also contribute to the low filling rate and weight of the grains on IS. In addition, a low abscisic acid /ethylene ratio and cytokinins and indole acetic acid contents were also considered important in this regard. Exogenously applied ABA or mild water stress, which resulted in a significant increase of grain ABA content at the early grain-filling stage, significantly stimulated the grain-filling of IS. A complex biological process, filling of a rice grain involves 21,000 genes including 269 that are closely related to various physiological and biochemical pathways. Thus, to understand the process thoroughly, not only the conventional physiological and biochemical means, but also the molecular methods, must be applied.