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Fig. 1. KATP channels are involved in hatching gland function. A,B:
Immunohistochemistry using an antibody to Kir6.1 reveals the presence
of KATP channels in the Y-shaped tissue of the hatching gland. C: SUR1
protein is strongly expressed in the head but is strikingly absent from the
hatching gland cells, the cement gland, and the tissue between the two
frontal arms of the hatching gland Y shape. D: SUR2 is present in the
hatching gland. E: Control embryos hatch by stage 29. F: In contrast,
embryos exposed to Nicorandil, an opener of KATP channels, remain in
the vitelline membrane and are unable to hatch. G: Individual embryo
showing morphology at stage 38. H: Individual embryo manually freed
from the membrane shows normal development to this late stage, despite
confinement to the vitelline membrane. I: Connexin30 is normally strongly
expressed in the hatching gland. J: Embryos exposed to Nicorandil show
a much reduced expression of Cx30 in the same tissue (white arrow).
Compared with control embryos (K), the expression of the hatching
enzyme is equally strong in Nicorandil-exposed embryos (L), showing
that the tissue is alive and that the cells maintain hatching gland identity.
Red arrows indicate expression. Green arrows indicate lack of expression |
