published_or_final_version / Zoology / Doctoral / Doctor of Philosophy

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

The splotch (sp) mutation has been identified as a mutation in the paired box gene, Pax-3. Heterozygous mice carrying this mutation are phenotypically normal, with the exception of a white spot on their bellies. Homozygous embryos do not live to birth, and suffer from a wide range of developmental defects, all of which result from delayed neural tube closure, or inadequate neural crest cell migration. Most notably, homozygotes have an increased rate of spina bifida with or without exencephaly. Retinoic acid (RA), which has been shown to be very important in the development of a number of systems, was shown to cause a selective mortality of the homozygous splotch embryos when administered maternally at day 9 p.c. (Moase and Trasler, 1987). Since cellular retinoic acid binding protein (CRABP) is localized to the tissues which are affected by both the splotch gene, and retinoic acid teratogenesis, its expression patterns in the developing splotch embryo were examined. It was found that the distribution of CRABP mRNA is normal, but its expression levels are excessive in splotch homozygous day 9 mouse embryos.

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Graduation date: 1993