Quantifying the spatial relationship between PORCN and JAG1 in the Mouse Cochlea


Emily Burt

Document Type


Publication Date

Summer 2022



JAX Location

In: Student Reports, Summer 2022, The Jackson Laboratory


The mammalian cochlea has a very highly specialized organization that is essential for auditory function. The molecular players on how this organization is attained is still unclear; however, the Wnt pathway has been shown to be essential for influencing patterning programs. Porcupine (PORCN), an O- acyl transferase that is required for WNT secretion, is found throughout the medial compartment of the cochlea on embryonic day (E) 14.5, when the sound-detecting inner hair cells (IHCs) are born. Jag1, an important prosensory gene, is regulated by the Wnt pathway during a specific stage of development when prosensory cells are specified. In this study, I characterize the spatiotemporal expression pattern of Jag1 relative to PORCN to determine whether the refinement of Jag1 is also driven by the Wnt pathway. Based on our findings, we predict that Jag1 is spatially repressed in one of two medial domains where PORCN is highly enriched in the cochlea. We hypothesize that Mybl2, a novel candidate Wnt target gene in the cochlea, spatially inhibits Jag1 expression leading to its refinement. Our long-term objective is to investigate a potential incoherent feed-forward gene regulatory circuit in which the Wnt pathway regulates both Jag1 and Mybl2.

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