[BBC] PhD defense Morgane Thomas-Chollier

[Morgane THOMAS-CHOLLIER]

PhD Public defense - Morgane Thomas-Chollier

Title: "Evolutionary study of the Hox gene family with matrix-based
bioinformatics approaches"

joint PhD supervision between the Vrije Universiteit Brussel (Prof. L.
Leyns - Laboratory of Cell Genetics) and
the Université Libre de Bruxelles (Prof J. van Helden - Service de
Bioinformatique des Génomes et des réseaux (BiGRe))


June 27, 2008, at 16:00
Vrije Universiteit Brussel - Campus Etterbeek
Pleinlaan 2, 1050 Brussels
Building D, room D2.01 « promotiezaal »
Access : http://www.vub.ac.be/image/3brussel_large.jpg


Hox genes belong to the family of homeobox transcription factors
characterised by a 60 amino acids region called homeodomain. These genes
are evolutionary conserved and play crucial roles in the development of
animals. In vertebrates, this family of genes can be divided into 14
groups of homology. The first goal of this thesis was to design an
automated approach to assign the growing number of Hox sequences into
their groups of homology. The resulting program, HoxPred, classifies Hox
sequences on the basis of their scores for a combination of protein
generalised profiles. This program was applied to clarify the
evolutionary history of the HoxC1a genes in teleost fish.
As transcription factors, Hox proteins regulate target genes by
specifically binding DNA on cis-regulatory elements. Only a few of these
target genes have been identified so far. The second goal of this work
was to evaluate whether it is possible to apply computational approaches
to detect Hox cis-regulatory elements in genomic sequences. For this, we
participated to the development of matrix-based pattern matching
approaches in the Regulatory Sequence Analysis Tools. After having
performed a statistical validation of the pattern-matching scores, we
focused on a study case based on the vertebrate HoxB1 protein, which
binds DNA with its cofactors Pbx and Meis. The study aimed at predicting
combinations of cis-regulatory elements for these three transcription
factors.

Contact person : morgane at bigre.ulb.ac.be