Biology Reference
In-Depth Information
FIGURE 10.6
Vibrating probe apparatus used to measure embryo-scale electric fields.
least 50 percent of which is carried by sodium ions.
29
Currents therefore flow in the same
direction in the blastopore as they do in a corneal wound, and any tangential field will be
in the same direction, the pore appearing as a cathode (sink for positive ions) from the point
of view of cells on the inside and appearing as an anode (source of positive ions) from the
outside. This highlights an important difference between the systems; in corneal wound heal-
ing, cells migrate towards the cathode whereas in
X. laevis
they are travelling towards an
effective anode when moving towards the pore on the outside, when they move through it
FIGURE 10.7
The blastopore in embryos of
X. laevis
.
