Small deletion in the exon that encodes the signal peptide sequence of secreted forms of Treh. The deletion present in the progenitor Trehc1 allele (which is in the first exon present in the major cytoplasmic isoforms) is also still present.
lethal - all die during P-stage
Trehc1+s3/Trehc1+s3 mutants exhibit lethality during pupal stage.