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Fig. 6.2 Asymmetric stem cell division regulated by extrinsic/intrinsic fate determinants.
a Asymmetric stem cell division regulated by extrinsic fate determinants. The extrinsic fate
determinants (brown) are short ranged and localized within the stem cell niche, promoting self-
renewal and/or repressing differentiation. Stem cells (blue) are located inside the niche, receiving
fate determinants and maintaining stem cell function. Upon stem cell division, the mitotic spindle
is stereotypically positioned so that the two daughters will be placed either inside or outside the
stem cell niche, becoming either stem cell or differentiating cell. b Asymmetric stem cell division
regulated by intrinsic fate determinants. The polarity of the stem cell is established by intrinsic
fate determinants (brown) preferentially localized on the apical end of the cell. Upon cell
division, self-renewal and differentiating factors are segregated so that self-renewal factors are
concentrated at the apical end and differentiating factors are localized at the basal end. After cell
division, one daughter cell receiving self-renewal factors maintains self-renewal ability while the
other daughter cell acquiring differentiating factors differentiates
6.2.2 Asymmetric Stem Cell Division Regulated
by Intrinsic Fate Determinants
Asymmetric stem cell division can also be achieved through the asymmetric
segregation of intrinsic fate determinants (Knoblich
2008
; Yamashita et al.
2010
).
Before/during cell division, intrinsic fate determinants are asymmetrically local-
ized in the stem cell, and then unequally segregated into two daughter cells after
the completion of mitosis, leading to the asymmetric fates of the two daughter cells
(Fig.
6.2
b). Drosophila neural stem cells, also known as neuroblasts (NB), provide
one of the best-studied examples of the regulation of asymmetric stem cell division
by intrinsic fate determinants (Knoblich
2008
; Prehoda
2009
). In NBs, apical-basal
