btlH82Δ11 embryos show reduced tracheal branch outgrowth compared to wild-type embryos but show no defects in branch integrity.
In btlH82Δ11 embryos, the migration of all primary tracheal branches is affected. Some branches, such as the dorsal trunk, ganglionic and visceral branches initiate but do not complete their migration. In btl95/btlH82Δ11 embryos, migration of all primary tracheal branches is affected to varying degrees.
Tracheal pits form, but tracheal cells undergo only limited migration.