Verena Koelsch, Thomas Seher, Maria Leptin.
University of Cologne, Institute for Genetics, Cologne, Germany.
Gastrulation in Drosophila is controlled by the transcription
factors twist and snail. In mutants for these genes
the mesoderm does not invaginate. The known targets of Twist and
Snail such as folded gastrulation cannot be the only genes
required for ventral furrow formation, because their phenotypes are
less severe: gastrulation is delayed but eventually the mesoderm
invaginates. We have screened a collection of deficiencies for other
genes that contribute to ventral furrow formation. We found that
embryos lacking region 97A-98A show a clear gastrulation phenotype:
the invagination of the mesoderm is delayed but not completely
blocked. We have identified the gene T48 responsible for the
phenotype. T48 is expressed in the early mesoderm and is
regulated by Twist. It encodes for a transmembrane protein and has a
PDZ-binding motif at the C-terminal end. We are currently analysing
the role of T48 and its potential interaction partners during
ventral furrow formation.