Remobilizing P elements out of the stambh A locus of Drosophila melanogaster

P elements from two P-tagged alleles, stm A(P1) and stm A(P4), of the tempe rature-sensitive paralytic mutant stambh A (stm A) were remobilized to deri ve wild-type revertants and P excision lethals. stm Apt remutated to lethal ity, while stm A(P4) reverted to the wild type. The P excision lethals are not amorphic mutations, since they were weaker in paralytic phenotype (i) t han the parental P-tagged allele and (ii) for deficiencies for stm A. The l ethals collectively affected all stages of the life cycle, demonstrating th at stm A(+) is needed throughout fly development.