Nucleotide substitution: G?A.
Amino acid replacement: R863H.
G14082284A
G?A
R863H | btl-PA; R863H | btl-PB
R863H
btl1118 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.