The independent regulatory element responsible for the control of mutability at vp-m451 (derived from a Mutator source) was tested against receptor elements of known systems (Scheffler and Peterson, MGN 59:4). The test demonstrated that the unknown regulatory element activated bz-rcy (a tester for the regulatory element Cy) and the unknown element did not activate receptor testers for Ac, Bg, Dt, En, Mrh, Mut or Uq. Due to the relationship tests, the receptor element of vp-m451was designated as the Cy receptor element vp-rcy, derived from a Mutator source. The design of the test also allowed for the detection of any known regulatory elements in a Mutator-derived line that carried vp-m451. Active regulatory elements Ac, Bg, Dt, En, Mrh, Mut, and Uq were not found in the line, only active Cy was present.

In order to confirm the relationship of vp-m451 to the Cy system, tests have been conducted to see if vp-rcy can be activated by any of the known regulatory elements. The relationship of vp-m451 to the Cy system was confirmed, in that vp-rcy was only activated in the presence of Cy. The relationship of Cy to Robertson's Mutator system (Schnable and Peterson, MGN 59:4-5 and 60) and the confirmation that the receptor element vp-rcy responds to Cy demonstrates that genetically defined receptor elements (rcy) can be derived from Mutator lines. These genetic data indicate that Robertson's Mutator is no longer unique, in that a mutant derived from it can be defined in the terms of a classical two-element system.

Brian E. Scheffler and Peter A. Peterson
 
 

Return to the MNL 60 On-Line Index
Return to the Maize Newsletter Index
Return to the MaizeGDB Homepage