|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 4. Core polarity gene function in the polar follicle cells affects border
cell migration. (A) Chart showing the extent of border cell
migration for clusters in which either fz, dsh or stbm
transcripts have been knocked-down by UAS-RNAi constructs under the
control of the polar follicle cell-specific upd-GAL4 driver at
29°C (Tsai and Sun, 2004).
Knockdown of fz transcripts causes a significant increase in the
number of clusters `behind' (see Fig.
1), whereas knockdown of dsh causes no delay in
migration. Knockdown of stbm in flies carrying two copies of the
endogenous stbm locus causes a mild delay in border cell migration,
which is greatly enhanced by the removal of one copy of the endogenous locus.
(B) Chart showing the proportions of genetically mosaic clusters
recovered for the strong alleles fz15 and
stbm6 with both polar follicle cells lacking gene
function, and either wild-type border cells leading (pink bars) or mutant
border cells leading (blue bars). Mutant cells in the cartoons are represented
by grey shading, with leading cells to the right and lagging cells to the
left. In the small number of fz mosaic clusters recovered
(n=6), we saw no clusters with a wild-type border cell leading, which
only deviates from the null hypothesis that border cell position is random at
a significance level of P=0.034. In the stbm mosaic clusters
recovered (n=10), both wild-type and mutant border cells are seen
leading, and the result fits the null hypothesis that border cell position is
random (P=0.5). (C) Chart showing the proportions of
genetically mosaic clusters recovered for the strong fz15
allele with only one polar follicle cell lacking gene function. Two classes of
clusters were recovered (n=15); both had the non-mutant polar
follicle cell touching the leading border cell, with the genotype of this
leading border cell approximately equally distributed between wild type and
mutant. The leading position of the polar follicle cells strongly deviates
from the null hypothesis that polar cell position is random
(P=0.0003), whereas the position of the border cells fits the
hypothesis that this is random with respect to the genotype of the border cell
(P=0.71). The data suggest that border cell position is determined by
the genotype of the polar follicle cell with which they make junctional
contact, regardless of the genotype of the border cell. (D) Chart
showing the proportions of genetically mosaic clusters recovered for the
strong stbm6 allele with only one polar follicle cell
lacking gene function. Two classes of clusters were recovered (n=9);
both had non-mutant border cells leading the cluster, with the genotype of the
polar follicle cell touching the leading border cell being either mutant or
non-mutant. The leading position of wild-type border cells does not fit the
null hypothesis that position is random (P=0.018). The position of
the wild-type polar cells fits the hypothesis that this is randomly determined
(P=0.51).
|
