Splice acceptor site mutation in intron 3; truncation in T-box domain.
G5465893A
G4255A
Nucleotide substitution: AG changed to AA in the splice acceptor.
midS0021 mutant embryos show cardioblast (CB) patterning defects and a lower generic CBs:ostial CBs ratio than the typical 4:2 ratio.
Chromosome also carries a second site mutation in bib.