The main interest of our laboratory
is concerned with the molecular mechanism
that leads to the two-fold up regulaton
of all X-linked genes in males (Dosage
compensation). Five genes involved
in this process have been characterized
both at the genetic and molecular level.
They are collectively called the "male-specific
lethal" (msl) genes, since mutations
in each of them cause male-specific
lethality. All encode nuclear proteins
that associate specifically with the
single X chromosome of male cells.
It is thought that this association
leads to a modification of X chromatin,
resulting in increased and more efficient
transcription of X-linked genes, but
the mechanism of how this is achieved
remains unknown. Recently, others and
we have shown that the Msl association
with the male X chromosome is accompanied
with the simultaneous association of
two RNAs, roX1 and roX2, both of which
are encoded by genes that map on the
X-chromosome. We are interested if
and how these RNAs mediate the Msl-
X-chromosome interaction and we use
both genetic and molecular strategies
to address this question. A second
interest of the laboratory is concerned
with olfactory perception of the fruit
fly. Olfaction in Drosophila is mediated
through a large family of sixty-seven
transmembrane proteins that are expressed
in the antenna (the 'fly nose') and
are thought to mediate specific behaviors
of the fly in response to different
odorants. We are employing a molecular
genetic strategy to generate flies
that can only express one functional
receptor to determine ligand specificity
of such receptors. Furthermore, we
are interested in systematic changes
that take place during development.
The larval olfactory system is replaced
by the adult olfactory system during
metamorphosis. Interestingly, the odorant
receptors that are expressed in the
adult are not expressed in the larval
olfactory system. Thus, another yet
unknown class of receptors must mediate
larval olfactory behavior and we employ
a molecular analysis of candidate genes
obtained from the Drosophila Genome
Sequence to identify these larval olfactory
receptor genes. Trainees are able to
participate in this research by being
involved in the various aspects of
all the experiments for these projects.
