Muzhizha ra1944, paCold Spring Harbor Laboratory, McClintock akatanga zvidzidzo zvakarongeka pamusoro pemitemo yemhando yemhando yemhando yemhando yembeu yechibage uye nhaka isingagumi yeiyi mosaicism. Akaziva maviri matsva makuru uye anobatana majini loci ayo aakatumidza Dissociation (Ds) uye Activator (Ac). Akawana kuti Dissociation haina kungoparadzanisa kana kukonzera kuti chromosome iputswe, yakanga inewo migumisiro yakasiyana-siyana pamagenes akavakidzana apo Activator yaivepowo, iyo yaisanganisira kuita kuti zvimwe zvigadziriswe zvigadziriswe zvisingaiti. Mukutanga kwa1948, akawana kushamisika kuti zvose zviri zviviri kushamwaridzana uye Activator zvaigona kumira, kana kuti nzvimbo, pane chromosome. Akacherechedza migumisiro yekushandurwa kweAclin uye Ds nekushandurwa kwemavara emhando yemhando yemhando yemhando yemhando yemhando yechibage pamusoro pemhando dzechibage, uye kusagadzikana kwemhando iyi yakasiyana.
Suppressor-mutator