|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 7. Alternative deployment of the micromere-PMC GRN. (A) In
undisturbed embryos, only micromeres (red cells in the early embryo), or more
precisely, their large daughter cells, give rise to PMCs (red cells at the
blastula stage) and the embryonic skeleton (red rods in the early larva).
(B,C) Removal of micromeres or PMCs leads to deployment of the
skeletogenic GRN by NSM cells, which are derived from macromeres (yellow)
(Hörstadius, 1939;
Ettensohn, 1992). (D-F)
Animal cells, derived from mesomeres (blue), can be induced to activate the
skeletogenic GRN by LiCl treatment
(Livingston and Wilt, 1989),
by the mis-expression of Delta (Sweet et
al., 2002) or of Pmar1
(Oliveri et al., 2002), or by
inductive signals from micromeres
(Minokawa et al., 1997).
|
