Handler A M, Gomez S P, O'Brochta D A
Insect Attractants, Behavior and Basic Biology Research Laboratory Agricultural Research Service, U.S. Department of Agriculture, Gainesville, Florida 32608.
Mol Gen Genet. 1993 Feb;237(1-2):145-51. doi: 10.1007/BF00282795.
A transient in vivo P element excision assay was used to test the regulatory properties of putative repressor-encoding plasmids in Drosophila melanogaster embryos. The somatic expression of an unmodified transposase transcription unit under the control of a heat shock gene promoter (phs pi) effectively repressed P excision in a dose-dependent manner at very low concentrations relative to somatically active transposase (encoded by the hs pi delta 2-3 gene). Maximum repression required transcription of the complete transposase gene. Dose-dependent repression of P excision was also observed in the presence of a vector plasmid (pCarnegie4) having only the terminal sequences, including transposase binding sites, of the P element. However, repression required considerably higher concentrations of pCarnegie4 than phs pi, and elimination of P excision was not observed.
采用瞬时体内P因子切除试验来检测黑腹果蝇胚胎中假定的阻遏物编码质粒的调控特性。在热休克基因启动子（phs pi）控制下的未修饰转座酶转录单位的体细胞表达，相对于体细胞活性转座酶（由hs pi delta 2-3基因编码），在非常低的浓度下以剂量依赖的方式有效地抑制了P因子切除。最大抑制需要完整转座酶基因的转录。在仅具有P因子末端序列（包括转座酶结合位点）的载体质粒（pCarnegie4）存在的情况下，也观察到了P因子切除的剂量依赖性抑制。然而，抑制所需的pCarnegie4浓度比phs pi高得多，并且未观察到P因子切除的消除。
