Jumping Translocation Breakpoint Expression in Midgestation Mouse Embryos.

Jumping translocations (JTs) can lead to partial trisomies. A breakpoint within the gene known as Jumping Translocation Breakpoint (JTB) has previously been associated with JTs involving the long arm of human chromosome 1 (1q). These 1q+ amplifications are frequently observed in cancer. JTB was initially mapped to the Epidermal Differentiation Complex (EDC) at 1q21, and earlier studies primarily focused on its role in malignant or adult tissues. Using updated genomic data, we refined the mapping of JTB. We employed RNA in situ hybridization (RISH) to visualize Jtb expression with organ, tissue, and cell-level resolution. We demonstrate that human JTB and murine Jtb are located outside the EDC. In midgestational wild-type mouse embryos, Jtb is expressed in multiple tissues, including the developing heart and vertebral column, and shows partial overlap with the expression of early markers of the neural crest cell lineage. Our findings suggest that the oncogenic potential associated with human JTB translocations is likely unrelated to its previously assumed location within the EDC.