trxJY16 is associated with a chromosomal break in the region encoding exon 3. The resulting fusion gene can express unaltered TRXI isoform and perhaps a form of TRXII isoform with novel N-terminal residues.
Breakpoint lies within the region encoding amino acids 172-276
19.9% of heterozygous adults show at least one transformation phenotype. trxJY16 die as small, lethargic third instar larvae. They do not have obvious segmental transformations, but their trachea are convoluted and may be disjointed.
Partial complementation between hypomorphs produced phenotypes that were weaker than either of the hemizygous or homozygous phenotypes, either rescuing lethality or producing a weaker homeotic transformation phenotype. Transformations range from an average of 1.86 to 17.50 transformations/fly (males were scored for a possible 29 transformations, females were scored for a possible 26 transformations) in different allelic combinations.
The following alleles form a series of progressively increasing penetrance and expressivity of phenotype when in transheterozygous combination with trx1 : trxM17 > trxZ32 > trxZ16 > trxZ11 > trxM18 = trxJY16 > trxE3.