Comprehending the mechanisms behind gene expression and its regulation plays a vital role in unraveling the intricate processes occurring within living organisms. Drosophila melanogaster's genome has been extensively studied through a multitude of transgenesis experiments made possible by the introduction of transgenes. Swoosh (SW) is a novel expression pattern of a white+ (w+) transgene in Drosophila melanogaster being studied in the Marcey laboratory. The SW phenotype displays w+ low-level expression throughout the eye with a band of high-level expression along the D-V equator, with adjacent curving. This expression pattern suggests that the transgene has fallen under the transcriptional control of a nearby important developmental gene that is expressed equatorially. The equator is an important signaling center during eye development. We are molecularly mapping the insertion site of the w+ transgene in order to search for this putative developmental regulator in nearby genomic sequences. Our objective is to isolate and determine the precise genomic coordinates of the SW, w+ transgene, along with its surrounding DNA, in order to comprehend its potential interaction with a gene of developmental importance indicated by the transgene's equatorial expression. To explore genes that may influence the expression of the SW transgene, bioinformatic analysis of SW will be performed, using w+ primers and PCR with genomic DNA obtained from genetic lines containing SW. The aim of this research is to further enhance our understanding of epigenetic control, the molecular mechanisms involved in development, and the modification of gene expression in genetically engineered organisms.

Polymerization of the cytoskeletal protein actin into branched filament networks generates forces that power cell movement. These branched networks sense and respond to external forces and adapt by altering the branch density. The Arp2/3 complex is a complex of 7 proteins including 2 actin-related proteins that bind and hydrolyze ATP (Arp2 and Arp3) that nucleate new branches (referred to as “daughter” filaments) on existing “mother” filaments. Abnormal expression of Arp2/3 subunits has been linked to the proliferation and pathology of various cancers and neurological dysfunctions. It is crucial to comprehend Arp2/3's structural and functional characteristics as well as the molecular processes that control its activity if we are to understand the molecular origins of these disorders and develop novel treatment approaches. Of particular relevance is how the stability of these branched networks responds and adapts to force. Past research in this lab has shown that the Arp2/3 complex from fission yeast “ages” and debranches more easily under force (applied with hydrodynamic flow) when it hydrolyzes and subsequently releases the gamma phosphate from ATP. We are currently investigating if the human Arp2/3 complex also “ages” the same way and identifying if Arp 2 and/or Arp 3 are responsible for this “aging” effect with hydrolysis inactive Arp2 and/or Arp3 mutants.

Understanding gene expression and its regulation is crucial for unraveling the complexities of biological processes in organisms. The genome of Drosophila melanogaster has been the target of a multitude of transgenesis experiments since transformation via transgenes became available. The white+ (w+) transgene has commonly served as a reporter due to its ability to facilitate the identification of transformed organisms. In a genetic background where individuals exhibit a white-eye phenotype (white-), the expression of the w+ transgene allows for the quick identification of transformed organisms, which display a red pigment phenotype in the eye. Interestingly, the expression of the transgene is variable in transformed flies, with expression patterns being affected by genomic location, epigenetic status, and regulation by genes in the area of insertion. Our transgene of interest, deemed Racing Stripe (RS), is expressed along the dorsal ventral midline, “equator” region and important developmental signaling center of the Drosophila eye. Our objective is to isolate and determine the precise genomic coordinates of the RS, w+ transgene and its flanking DNA, to understand its potential interaction with a developmentally important gene indicated by RS's equatorial expression. We will conduct bioinformatic analysis to explore genes that influence RS transgene expression. A forensic analysis of RS will be conducted using w+ primers and PCR with genomic DNA from RS-containing genetic lines. The work aims to further elucidate the nature of epigenetic control, molecular mechanisms of development, and gene expression modification in genetically engineered organisms.