This material has been published in Developmental Biology 162(2):394-401, the only definitive repository of the content that has been certified and accepted after peer review. Copyright and all rights therein are retained by Academic Press. This material may not be copied or reposted without explicit permission. Copyright © 1994 by Academic Press)

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Developmental Biology 1994 Apr;162(2):394-401

Effects of localized application of retinoic acid on Xenopus laevis development.

Drysdale TA, Crawford MJ

Department of Zoology, University of Toronto, Ontario, Canada.

In order to more accurately determine the mechanism by which retinoic acid
causes embryonic defects, we have developed a simple method of locally applying
retinoic acid rather than immersing the whole embryo in retinoic acid solutions.
Retinoic acid was suspended in corn oil and then injected between the surface
and the deep ectodermal layers of an early gastrula Xenopus embryo. When
droplets containing retinoic acid were injected into the presumptive head
region, the embryos exhibited inhibited development of anterior structures near
the injection site. Development of the eye, cement gland, hatching gland,
olfactory pits, and expression of engrailed protein were all disrupted near the
injection site. Inhibited development of anterior structures was far greater on
the injected side of the embryo than on the uninjected side. The retinoic acid
droplet did not cause an anterior shift of structures on the injected side
relative to the uninjected side. These experiments suggest that retinoic acid
does not cause global respecification of axial level in the head, but rather
suppresses development of anterior structures. Retinoic acid injected into
presumptive trunk regions had no discernible effect.

PMID: 8150203, UI: 94200510
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