Fig. 6. The QA motif is preferentially required for A1 tergite formation. Deletion of the QA motif had a strong effect similar to that of removing one dose of Ubx. Genotypic series of A1 tergite formation as assessed by number of rows of bristles: (A) Ubx⁺/Ubx⁺ > (B) Ubx^–/Ubx⁺ (C) Ubx^QA/Ubx^QA > (D) Ubx^QA/Ubx^–. Pooling all data, Ubx⁺/Ubx⁺ A1 tergites had 5.32±0.49 rows of bristles, Ubx^–/Ubx⁺ A1 tergites had 4.44±0.44 rows of bristles, while Ubx^QA/Ubx^QA A1 tergites had 4.26±0.49 rows of bristles (for either comparison to Ubx⁺/Ubx⁺, P<10^–22; Ubx^–/Ubx⁺>Ubx^QA/Ubx^QA, P=10^–2; n=80, 120, and 180; respectively). In the WI129 background (shown above), Ubx^–/Ubx⁺ A1 tergites (B) had 4.68±0.39 rows of bristles, while Ubx^QA/Ubx^QA A1 tergites (C) had 4.28±0.59 rows of bristles (P=10^–4; n=60 and 90, respectively). In the Oregon-R background (not shown), Ubx^–/Ubx⁺ A1 tergites had 4.20±0.36 rows of bristles, while Ubx^QA/Ubx^QA A1 tergites had 4.23±0.51 rows of bristles (P=0.7; n=60 and 90, respectively). Anterior is upwards.