Our ability to discriminate different smells depends on the systematic organization of olfactory sensory inputs, or glomeruli, in the olfactory bulb. This stereotyped arrangement of glomeruli is also called the olfactory map. Understanding how the map forms during embryogenesis is therefore critical for understanding how our sense of smell develops. However, little is known about how the pattern of glomeruli is organized. We recently found that the Wnt5 protein is expressed in restricted domains in the developing Drosophila olfactory bulb, and may act as a prepattern for the fly olfactory map. Indeed, loss of the wnt5 gene severely disrupted the patterning of the glomeruli. We propose that novel Wnt5-expressing “guidepost” cells create the pattern of the Wnt5 protein. To characterize these guidepost cells we have begun the process of placing the Gal4 gene under the control of the wnt5 promoter and identifying the Gal4 gene expression pattern. To target the wnt5 promoter with the Gal4 gene, we used the technique of gene targeting by homologous recombination. We screened total of 306,200 flies and found mobilization of the Gal4 gene in 320 animals (158 males and 162 females) with a mobilization frequency of 1 in 1,000 animals screened. Of these, we mapped the Gal4 gene to the X chromosome in 18 animals with an X chromosome frequency of 1 in 17,000, which are potentially the results of homologous recombination in the wnt5 gene. The expression pattern of the Gal4 gene has been visualized using UAS-mGFP at different stages of Drosophila development.
|Presenter:||Jay-Christian Helt (SUNY Brockport) -- email@example.com
|Topic:||Biology - Panel|
|Time:||11:10 am (Session II)|