During his summer with BSURF, Zach is working with the McClay lab (which actually shares a space with the Wray Lab where I am working this summer). Dr. McClay is known for dedicating his career to mapping the gene regulatory network (GRN) of the model organism sea urchins. GRNs are very complex, specific, and intricate; many genes may be influencing the expression of one gene, and one gene may be influencing the expression of many genes. Zach is taking up a small part of the sea urchin embryo GRN, specifically looking at the gene Astacin-4, expressed in immune cells in the sea urchin. Very little is known about Astacin-4, but Zach is dedicated towards figuring it out – asking questions such as what genes are upstream, what genes are downstream, when it is activated, how long it takes to become activated, and what its primary function is. What is known about Astacin-4 is that it is expressed in cells known as blastocoels, located on the left side of the early developing sea urchin embryo. Establishing a GRN is a long and tedious process that includes continuously conducting a protocol known as in situ hybridizations. In simple terms, in-situs are conducted by throwing a cocktail of antibodies and G markers together with the developing embryo to see where and when Astacin-4 is expressed. By manipulating the system through gene inhibition or upregulation, the GRN of Astacin-4 can slowly be uncovered and mapped. Once the GRN for Astacin-4 has been defined, it may have applications in all types of other organisms, such as humans.