You work in Marc Tessier-Lavigne's lab, and you are studying axon guidance. Please answer the following questions about guidance of axons in embryos. You are reviewing previous axon guidance experiments. Your Ph.D. thesis work involves a set of cells in the ventral spinal cord that normally migrate dorsally. In netrin-1 KO mouse, axons should stray towards ventral region of the spinal cord 7.
Transcriptional regulators influence a wide variety of developmental processes in Drosophila .
Bicoid is a transcriptional regulator of zygotic hunchback expression in the early embryo. Describe what happens to levels of hunchback mRNA in the following situations. Another well-studied example of transcriptional regulation in embryos is the way in which gap gene products regulate the expression of pair rule genes in Drosophila . The overlap of domains of expression of gap proteins determines where stripes of pair rule expression will appear. The regulatory region of each pair rule gene is sensitive to local combinations of transcriptional activators and repressors.