Daniel L. Weeks
Professor of BiochemistryDept. of Biochemistry
Univ. of Iowa
Iowa City, Iowa
319 335 7918
The developmental control of embryogenesis among organisms is highly conserved. We study the function of genes involved in congenital defects in humans by doing experiments with the frog Xenopus laevis. We take advantage of the relative ease of introduction of biomolecules like antisense oligonucleotides to reduce mRNA levels, or mRNA itself to make altered or increased levels of specific protein in live embryos. We then look for morphological and molecular changes in organs like the heart, ears and gut. One of the techniques we use is whole mount inmmunohistochemistry coupled to confocal microscopy. Xenopus embryos develop rapidly and are small enough to use for confocal microscopic analysis that allows both the exterior and the interior of developing organ system to be viewed. An example of these studies on the heart can be seen in images we have provided to the Xenopus web based resource, Xenbase (see http://www.xenbase.org/atlas/organs/heart/heart-confocal.html). We are developing and testing novel modifications of oligonucleotides to provide new ways to interfere with gene transcription and also to promote site directed mutations. We design, synthesize and use chemically modified cationic oligonucleotides that enhance oligonucleotide mediated alterations of gene expression. In addition, we are exploring methods that allow the introduction of new genetic material into embryonic genomes creating transgenic tadpoles. These methods will have applications in promoter analysis, studies on gene function and lineage tracing.
Lab MembershipsWeeks Laboratory (Principal Investigator/Director)