Fig. 5. Structure-function analysis of the Dome receptor. The migratory phenotype of BCs after overexpression of the JAK/STAT pathway components is analysed using slbo-lacZ as a reporter, which is expressed primarily in the BCs (arrowhead) at stages 9 and 10. (A) At stage 10, slbo-lacZ is also expressed in centripetal and posterior polar cells. (B-L) Overexpression, using a slbo-GAL4 line (Rorth, 1998), of Hop (B), Stat92E (C) or Upd (M) leads to aberrant BC migration. To test the domain requirements of Dome, several different constructs have been expressed (D) and the resulting phenotypes analysed (E-L, arrowheads indicate BCs). Overexpression of a wild-type Dome or of a Dome-GFP fusion protein leads to an absence of migration of BCs (E-H). Expression of truncated forms (DomeCYT or DomeEXT) blocks the recruitment of BCs, and only polar cells express slbo-lacZ (I-L). Note that even in late stage egg chambers (L; stage 11) polar cells are still present at the anterior pole. Co-expression of Upd and the dominant negative DomeCYT proteins in BCs completely suppresses the gain-of-function phenotypes associated with Upd overexpression (compare M and N). The frequency of BC migratory defects is indicated in the lower right corner of each panel. Anterior is to the left.

Return to article