Stead Family Department of Pediatrics

Daniel Weeks, PhD


Professor of Biochemistry
Professor of Pediatrics

Contact Information

Primary Office: 4-710 BSB
Iowa City, IA 52242
Phone: 319-335-7918

Web: Weeks Laboratory


BS, Biological Sciences, Microbiology, Purdue University
PhD, Biological Sciences, Purdue University

Post Doctorate, Dept of Biochemistry and Molecular Biology, Harvard University

Education/Training Program Affiliations

Department of Biochemistry PhD
Interdisciplinary Graduate Program in Molecular and Cellular Biology
Interdisciplinary Graduate Program in Translational Biomedicine
Medical Scientist Training Program

Research Summary

We take advantage of the conservation of developmental control of embryogenesis among organisms, to 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 that result. One of the techniques we use is whole mount immunohistochemistry 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. Our most current studies look at how amyloids are used as part of normal development. The extracellular formation of amyloid particles is part of the pathogenesis that accompanies devastating diseases like Alzheimer’s and Huntington’s disease. However, it is increasingly clear that the formation of amyloids, most commonly the formation of proteins into cross-beta strand structures rather than their active, native three-dimensional structure, may be non-pathogenic and even advantageous. The best current examples of the formation of advantageous amyloid-like structures come from studies in yeast, where stress responsiveness and the ability to adapt to changing nutritional conditions are mediated thought the assembly and disassembly of amyloid-like structures. The formation of amyloid-like structures were also critical for long-term memory in studies using snails and fruit flies. As the features that allow a protein to form an amyloid as an alternative to it’s active structure become better understood the surprising result is that at least 5% of known proteins meet the requirements. We now know that in oocytes the nuclear particles where transcription and RNA processing occurs contain amyloids, and amyloids can be found in the nucleus and cytosol of the dividing cells of the early embryo. We are investigating what proteins are forming amyloids and how they are assembled and disassembled as part of normal development.

Selected Publications

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Li Y, Manaligod J, Weeks D.  EYA1 mutations associated with the branchio-oto-renal syndrome result in defective otic development in Xenopus laevis.  Biology of the cell / under the auspices of the European Cell Biology Organization.  2010 May. 102(5):277-92.

Bartlett H, Veenstra G, Weeks D.  Examining the cardiac NK-2 genes in early heart development.  Pediatric cardiology.  2010 April. 31(3):335-41.

Allen B, Weeks D.  Bacteriophage phiC31 integrase mediated transgenesis in Xenopus laevis for protein expression at endogenous levels.  Methods in molecular biology (Clifton, N.J.).  2009. 518:113-22.

Chesneau A, Sachs L, Chai N, Chen Y, Du Pasquier L, Loeber J, Pollet N, Reilly M, Weeks D, Bronchain O.  Transgenesis procedures in Xenopus.  Biology of the cell / under the auspices of the European Cell Biology Organization.  2008 September. 100(9):503-21.

Bartlett H, Weeks D.  Lessons from the lily pad: Using Xenopus to understand heart disease.  Drug discovery today. Disease models.  2008. 5(3):141-146.

Jacobi U, Akkers R, Pierson E, Weeks D, Dagle J, Veenstra G.  TBP paralogs accommodate metazoan- and vertebrate-specific developmental gene regulation.  The EMBO journal.  2007 September. 26(17):3900-9.

Bartlett H, Sutherland L, Kolker S, Welp C, Tajchman U, Desmarais V, Weeks D.  Transient early embryonic expression of Nkx2-5 mutations linked to congenital heart defects in human causes heart defects in Xenopus laevis.  Developmental dynamics : an official publication of the American Association of Anatomists.  2007 September. 236(9):2475-84.

Mitchell T, Jones E, Weeks D, Sheets M.  Chordin affects pronephros development in Xenopus embryos by anteriorizing presomitic mesoderm.  Developmental dynamics : an official publication of the American Association of Anatomists.  2007 January. 236(1):251-61.

Allen B, Allen-Brady K, Weeks D.  Reduction of XNkx2-10 expression leads to anterior defects and malformation of the embryonic heart.  Mechanisms of development.  2006 October. 123(10):719-29.

Collop A, Broomfield J, Chandraratna R, Yong Z, Deimling S, Kolker S, Weeks D, Drysdale T.  Retinoic acid signaling is essential for formation of the heart tube in Xenopus.  Developmental biology.  2006 March. 291(1):96-109.

Date Last Modified: 06/06/2016 - 13:17:48