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.
See a picture of Dr. Amrein's research
in our Gallery.
