Genetic studies showed that a single hierarchy of sex-specific regulatory genes controls all aspects of somatic sexual
differentiation in flies. Most of the laboratory's current work on sex determination is focused on the molecular analysis
of these regulatory genes with the aim of elucidating their biochemical functions. These studies have shown that the
sex-specific functions of these genes are the consequences of the alternative splicing of their primary transcripts in
females and males to produce messenger RNAs with different coding potentials in the two sexes. Moreover, the genes
at one level in the hierarchy encode proteins that regulate the processing of the pre-mRNAs of the genes in the next
level in the hierarchy. One area of current research is using this system to elucidate the molecular mechanisms by
which proteins regulate alternative pre-mRNA processing. Other research is directed at understanding how the final
genes in this hierarchy regulate the activities of the genes that encode the terminal differentiation products that produce
sex-specific biochemical, behavioral, and morphological characters.
Dosage compensation in flies is achieved by the doubling of the transcription rate of the genes on the single X
chromosome of the male so that it produces as much product as the two X chromosomes of the female. Research is
focused on how the five genes implicated in this process function to increase the transcription rate of the male's X
chromosome. Molecular and genetic analyses of these genes suggest that they encode products that assemble into a
complex which then binds to the male's X chromosome and increases its transcription rate. The mechanism by which
this occurs is being studied.
The genital imaginal disc gives rise to the internal and external genitalia of the adult and thus
shows substantial dimorphism in its development and differentiation. Research in the lab is directed at (1)
understanding at the genetic and molecular levels how the genital disc cells are initially specified in the
embryo; (2) how pattern formation occurs in this disc; and (3) the processes that drive the morphogenesis
of this disc.
This section will be updated (hopefully). See also recent publications.
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