Fig. 3. uif^2B7 mutant animals fail to establish fully inflated tracheae during embryogenesis.

Selected brightfield photomicrographs from a time-lapse series of an uif^2B7 mutant embryo showing a rapid period of tracheal inflation (A–E), followed by more than two hours with no additional inflation (F–I). Times given are relative to the start of observation which occurred in mid stage 17 of embryogenesis. The full time series can be seen in Supplemental movie 1. Note that the inflation phase lasts for seven minutes and results in fully inflated dorsal trunks with little inflation distal to the transverse connectives in each metamere. Arrows indicate the extent of inflation of the dorsal trunk during the initial inflation phase. Arrowheads in D and H indicate the extent of inflation in three adjacent metameres and show that there is no additional inflation of these segments over a 166 minute period. Even though the animal has not completed tracheal inflation, it hatches and crawls away (J).