Function and regulation of wishful thinking, a BMP type II receptor

Development is controlled by a surprisingly small number of genetic pathways. One such pathway is called the bone morphogenetic protein (BMP) pathway, similar from flies to humans. We used the common fruit fly, Drosophila melanogaster, to study the BMP pathway during Drosophila oogenesis, the formation of the egg. While the pathway is relatively simple, there exist combinations between the three different ligands, and four different receptors. My work focused largely on the two type II receptor, specifically on Wishful thinking (WIT). Much is known about the dynamic expression of the type I receptor during oogenesis, Thickveins. However, the pathway requires action of both type I and type II receptors. We found that WIT performs a necessary role during oogenesis and is regulated, indirectly, by BMP signaling. WIT is required for proper patterning of pathway target genes and necessary for proper formation of the eggshell. We also used a new technology, CRISPR/Cas9, to specifically remove the WIT locus from its endogenous location in the genome. This allowed for introduction of new alleles, including a tagged variant and conditional null, for future study of this gene. In the future, this may be applied to other genes in Drosophila oogenesis. Since gene patterning is crucial to development, we also worked in a collaborative effort to describe other complex gene patterns during Drosophila oogenesis. The Chorion proteins (CPs) are constituents of the eggshell and are expressed in a highly complex and dynamic fashion. We developed a system to computationally analyze gene pattering, dynamics, and conservation by utilizing a simple binary matrix. This matrix was then able to be used to predict the origin of a new domain in a related species of Drosophilid, the dorsal ridge of D. nebulosa and D. willistoni. This work served as a jumping point for multiple lab projects to study the patterning of this domain by another signaling pathway, the epidermal growth factor receptor (EGFR).Ph.D.Includes bibliographical referencesIncludes vitaby Robert Marmio