<i>p18ahub</i> affects the Integrator Complex Subunit 6 (Ints6).

(A) p18ahub was narrowed to an approximately 1.35 Mb interval between SSLP marker z7120 and an SSLP marker that we generated in BAC CR545476.14 (Zv9) (right marker) by examining meiotic recombination between markers flanking the mutation. The recombinants found in the number of meioses examined at each marker is shown and the positions of markers are approximate. (B) p18ahub is a T to A transition in an exon of ints6 that converts valine 375 to an aspartate. An alignment of several Ints6 proteins was generated using ClustalW and reveals that V375 is nearly invariant among widely divergent species. (C and D) In situ hybridization for ints6 transcripts on WT embryos at (C) 128-cell (n = 8) and (D) late blastula stage (n = 19); lateral views, animal to top. (E–G) Rescue experiments: pie charts show fractions of embryos evaluated at 1 dpf with indicated phenotypes. Numbers of embryos are shown in the center of each chart. (H) Uninjected p18ahub mutant embryos and (I) mutant embryos rescued by injection of 50 pg ints6 mRNA, shown at 1 dpf.