Sonja Vernes

Graduate Research Prize Winners 2008

In 2004 I was fortunate to be awarded a full scholarship by the Clarendon Fund and was later awarded the prestigious Christopher Welch Award in Biological Science, enabling me to begin my D.Phil. at the University of Oxford. Before this, I was an undergraduate at the University of Melbourne, Australia. As part of Dr. Simon Fisher's group at the Wellcome Trust Centre for Human Genetics (and co-supervised by Prof. K.E. Davies), my D.Phil. project focused on a particularly fascinating human gene, called FOXP2. This is the first gene to have been implicated in inherited speech and language disorders, a discovery that made a major impact on diverse research fields. FOXP2 encodes a type of regulatory protein that modifies the expression of other genes (a transcription factor). The aim of my project was to use this gene as a molecular window into neurogenetic mechanisms that are important for speech and language. The initial stage of work assessed the properties of the FOXP2 protein in human neuronal cell models, examining the functional consequences of causative point mutations found in families with severe speech and language problems. Mutations affected multiple aspects of FOXP2 function including nuclear localisation (see Figure), DNA binding and ability to regulate target gene expression.

My next step was to exploit FOXP2's role as a transcription factor to discover other genes involved in speech/language pathways, taking advantage of the latest developments in functional genomics. I was able to identify the first downstream neural targets regulated by FOXP2, employing a special technique to recover the parts of the genome bound by FOXP2 in living cells, followed by analyses with DNA-chips (microarrays) or sequencing to determine the identity of these genomic fragments. This strategy uncovered several key functional pathways that appear to be regulated by FOXP2, including synaptic plasticity, neurotransmission and axon guidance. Perhaps the most exciting finding from my DPhil research has been the discovery of functional genetic links between different types of language disorder. In collaboration with other research teams at the Wellcome Trust Centre, we have shown that, although mutations of FOXP2 itself are rare, the targets that it regulates may be more broadly implicated in common forms of language impairment.

Throughout my D.Phil I have been grateful for the opportunities afforded by studying at the University of Oxford. The Wellcome Trust Centre for Human Genetics (WTCHG) in addition to providing excellent facilities has allowed me to pursue my research goals in an atmosphere of collaboration and cooperation. The state of the art technology available at the WTCHG has allowed me to employ cutting edge techniques to address research questions and helped me to publish my work in high impact journals. A definite advantage of studying in Oxford is the large scientific community that is present, with world-renowned experts in a range of disciplines. Thus the opportunity for collaboration is vast and I have benefited greatly from interactions with many scientists from other labs. Furthermore my supervisors challenged and encouraged me throughout my D.Phil, helping me to develop my skills as an independent scientist. I was encouraged to attend international meetings and visit collaborators labs giving me the confidence to present and discuss my research in front of my peers. My time in Oxford has also been enriched by my membership of University College, which has given me the opportunity to meet people from a range of fields and backgrounds as well as try new sports and activities. I have recently been awarded a V.I.P award from the Wellcome Trust that allowed me to remain in the Fisher lab after the completion of my D.Phil to continue my research into FOXP2.

Figure legend. Intracellular localisation of mutant FOXP2 proteins. (A) Immunofluorescence of transiently transfected SH-SY5Y cells. Wild-type FOXP2 displays predominantly nuclear localisation. R553H shows both nuclear and cytoplasmic localisation and in a small number of cases R553H could be seen to form small aggregates. Q17L staining is nuclear and indistinguishable from the wild-type protein, whereas R328X consistently shows weaker staining which is largely cytoplasmic. Recombinant FOXP2 was detected using a FITC conjugated antibody to the N-terminal Xpress TM tag (green). DAPI counterstain (blue) indicates the location of nuclei. (Scale bar, 10 mM) (B) Western blot analysis of recombinant proteins transiently expressed in HEK293T cells. Cells were fractionated into nuclear and cytoplasmic compartments prior to SDS PAGE and Western blotting. Proteins were detected using an N-terminal FOXP2 Antibody (Santa Cruz Biotechnology) and equivalent loading was confirmed using the b-Tubulin internal loading control. The R328X protein could only be detected following extended exposure (overexposed panel).

Figure legend. Intracellular localisation of mutant FOXP2 proteins. (A) Immunofluorescence of transiently transfected SH-SY5Y cells. Wild-type FOXP2 displays predominantly nuclear localisation. R553H shows both nuclear and cytoplasmic localisation and in a small number of cases R553H could be seen to form small aggregates. Q17L staining is nuclear and indistinguishable from the wild-type protein, whereas R328X consistently shows weaker staining which is largely cytoplasmic. Recombinant FOXP2 was detected using a FITC conjugated antibody to the N-terminal XpressTM tag (green). DAPI counterstain (blue) indicates the location of nuclei. (Scale bar, 10 mM) (B) Western blot analysis of recombinant proteins transiently expressed in HEK293T cells. Cells were fractionated into nuclear and cytoplasmic compartments prior to SDS PAGE and Western blotting. Proteins were detected using an N-terminal FOXP2 Antibody (Santa Cruz Biotechnology) and equivalent loading was confirmed using the b-Tubulin internal loading control. The R328X protein could only be detected following extended exposure (overexposed panel).

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