The endogenous promoter of ZK813.1 (1046 bp) was replaced with the fln-1 promoter (947 bp) to limit the expression of ZK813.1 to the spermatheca and allow analysis of RNA transfer from soma to oocytes. Reference: Trimmer KA, et al. Cell Rep. 2023 May 23;42(6):112544. doi: 10.1016/j.celrep.2023.112544. PMID: 37227820. .