Amino acid replacement: R402term.
Nucleotide substitution: C?T.
C14080815T
C?T
R402term | btl-PA; R402term | btl-PB
R402term
btl1684 mutants do not exhibit tracheal terminal cells.
Mosaic tracheal branches (containing wild-type, heterozygous and homozygous cells) are grossly normal, but homozygous mutant clones rarely, if ever, include terminal cells.