The suppressor of Hairy‐wing [su(Hw)] protein mediates the mutagenic effects of the gypsy retrotransposon by blocking enhancer activity. These repressive effects are general, can occur over long distances and require that the su(Hw) protein is bound between the affected enhancer and promoter. The effects of the su(Hw) binding region on yolk protein (yp) gene expression were determined. These genes are regulated by shared enhancers in the intergenic region, which provided a method to examine whether an enhancer blocked by the su(Hw) protein remained functional. We demonstrate that a blocked enhancer is completely active, supporting the proposal that the su(Hw) protein is an insulator protein that acts by forming a new boundary in a pre‐existing chromatin domain, thereby preventing the interaction of regulatory elements located upstream of the insertion site with the promoter. In addition, we found that yp promoter function is not diminished by sharing enhancers, suggesting that these enhancers are not rate limiting for transcriptional activation. Lastly, our data indicate that yp promoter activity is interdependent, such that transcription from one promoter influences the level of activity of the linked promoter.

In recent decades, biologists have sought to tag animals with various sensors to study aspects of their behavior otherwise inaccessible from controlled laboratory experiments. Despite this, chemical information, both environmental and physiological, remains challenging to collect despite its tremendous potential to elucidate a wide range of animal behaviors. In this work, we explore the design, feasibility, and data collection constraints of implantable, near-infrared fluorescent nanosensors based on DNA-wrapped single-wall carbon nanotubes (SWNT) embedded within a biocompatible poly(ethylene glycol) diacrylate (PEGDA) hydrogel. These sensors are enabled by Corona Phase Molecular Recognition (CoPhMoRe) to provide selective chemical detection for marine organism biologging. Riboflavin, a key nutrient in oxidative phosphorylation, is utilized as a model analyte in in vitro and ex vivo tissue measurements. Nine species of bony fish, sharks, eels, and turtles were utilized on site atOceanografc in Valencia, Spain to investigate sensor design parameters, including implantation depth, sensor imaging and detection limits, fluence, and stability, as well as acute and long-term biocompatibility. Hydrogels were implanted subcutaneously and imaged using a customized, field-portable Raspberry Pi camera system. Hydrogels could be detected up to depths of 7 mm in the skin and muscle tissue of deceased teleost fish (Sparus aurata and Stenotomus chrysops) and a deceased catshark (Galeus melastomus). The