|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 6. smedbmp4-1 is expressed in the pre-existing tissue of
asymmetric fragments lacking a midline and expands towards wound sites in
asymmetric fragments containing a midline. (A-D) Diagrams show a
model of the smedbmp4-1-expressing midline, with black and red lines
indicating the sites of amputation or injury. Arrows indicate new
smedbmp4-1 expression. In situ hybridizations were performed with the
smedbmp4-1 riboprobe. (A,B) Anterior, left. Thin, lateral wild-type
fragments were generated that lacked a pre-existing midline. New
smedbmp4-1 expression was detected in these fragments by in situ
hybridization. (B) Animals were irradiated with 6,000 Rad prior to amputation.
New smedbmp4-1 expression was detected 48 hours later (left), which
failed to resolve to a midline pattern (right). (C) Representative animals
(thick fragments) fixed and labeled using the smedbmp4-1 riboprobe, 0
and 48 hours following amputation. `0' hours refers to all animals fixed
shortly (between 0 and 3 hours) after surgery. The pre-existing midline of
animals is defined as a line connecting the tip of the head through the
photoreceptors and the middle of the pharynx, to the tip of the tail. The left
(L) and right (R) regions of smedbmp4-1 expression were determined by
measuring the distance from the pre-existing midline to the end of the field
of expression just above and below the pharynx. Means were taken per animal
from these two measurements for both the left and right sides (red lines), and
at least eight animals were scored for each time point. The graph indicates
the mean ratios and standard deviations of measurements taken from wild-type
animals and from animals fixed shortly after amputation (0 h), 24 hours after
amputation, or 48 hours after amputation. Only animals missing their right
sides were scored. The ratio of the right distance to the left distance
indicated expansion towards the right, and was at each time point
significantly different from the controls (P<0.0001,
t-test). Furthermore, 66/73 fragments that were either in the 0 h or
a 24 h or later group could be identified correctly in blind scoring. (D)
Left, a wild-type animal was cut with a side nick perpendicular to the midline
(red line in diagram). The nick was allowed to seal and animals were fixed 26
hours later; no obvious change in smedbmp4-1 expression was detected
(n=24). Middle, a wild-type animal was cut with an internal nick
parallel to the midline (red line in diagram). The nick was allowed to seal
and was fixed 48 hours later; no obvious change in smedbmp4-1
expression was detected (n=15). Right, a wild-type animal was cut
longitudinally (red line in diagram). 48 hours later no obvious change in
smedbmp4-1 expression was detected (n=11). Scale bars: 0.1
mm. h, hours; d, day.
|
