Thesis (Ph.D.)--University of California, San Francisco, 2008. / Source: Dissertation Abstracts International, Volume: 69-09, Section: B, page: 5304. Adviser: Susan J. Fisher.

Thesis (Ph.D.)--University of California, San Francisco, 2009. / Source: Dissertation Abstracts International, Volume: 71-02, Section: B, page: . Adviser: Geeta J. Narlikar.

<p> Polymerase Chain Reaction (PCR) was developed for a broad range of purposes. As part of developing a very sensitive Immuno-quantitative PCR (iqPCR) assay, we attempted to reproduce two of the published papers, almost always experienced false-positive amplification. Based on personal communication from one of the authors, we suspected that impure reagents were responsible for the false-positive amplification. However, PCR can amplify a small number of DNA into enormous numbers of copies and the possibility of environmental contamination cannot be excluded. In this paper we show that our primers appeared to amplify residual DNA in the <i>Taq</i> DNA polymerase, and induced false-positive results. This finding is not in the published methods papers for iqPCR.</p>

<p> Cellular DNA is condensed and stored with the help of proteins, especially histones. This mix of DNA and proteins is termed chromatin. Manipulations of chromatin include post-translational modifications (PTMs) of histone proteins, such as the addition of methyl or acetyl groups, and the movement of histones by chromatin remodeling complexes to control how tightly or which regions of DNA are condensed or exposed. These actions can impact gene expression and thus influence the differentiation of tissues during development. I investigated if the enzyme protein arginine methyltransferase 5 (PRMT5), which mono- or symmetrically dimethylates arginine, is acting on histones during early development in Xenopus laevis. I also investigated if Williams syndrome transcription factor (WSTF) occurs within chromatin remodeling complexes during early development in X. laevis. WSTF interacts with the protein ISWI in early embryos, indicating it is part of a chromatin remodeling complex during this period of development. </p>