UC San Diego

The sea urchin faces a variety of environmental factors in the ocean, including small molecules. These small molecules can enter the cell and affect development, homeostasis, immunity, and cellular functions. Transcription factors play many roles, including the regulation of how these molecules enter and exit cells by altering expression of membrane proteins. Nuclear receptors (NRs) that aid in responding to small molecules by binding to these ligands, causing a downstream effect of altering the gene expression of target genes. In this thesis, I study a particular group of NRs, the Hepatocyte Nuclear Factors (HNF), which have been shown to play a role in responding to stimuli and to maintain metabolism and regulate development. Sea urchins need to adapt to dynamic environmental conditions by responding to specific stimuli. HNFs have been well studied in mammalian models, but there is a lack of a full description of HNFs within echinoderms. This is particularly useful to further understand these transcription factors in small molecules transport in a genetically enabled species. Here, I have identified and localized the four major types of HNFs - HNF1, HNF3, HNF4, and HNF6 within the sea urchin, Lytechinus pictus during early development.