ISOLATION OF MAIZE NUCLEAR MALE STERILE GENES BY TRANSPOSON-TAGGING

WE PROPOSE TO USE TRANSPOSON-TAGGING TO ISOLATE A NUCLEAR MALE STERILE (MS) GENE FROM MAIZE. WE HAVE GENERATED EIGHT NEW MALE STERILE MUTANTS IN STOCKS CARRYING THE TRANSPOSABLEELEMENT ACTIVATOR (AC) AND WE ARE CURRENTLY ANALYZING DNA FROM THESE MUTANTS FOR THE PRESENCE OF NOVEL RESTRICTION FRAGMENTS CARRYING AC HOMOLOGOUS SEQUENCES. PRELIMINARY ANALYSIS HAS ALLOWED US TO IDENTIFY SEVERAL UNIQUE RESTRICTION FRAGMENTS WHICH ARE PRESENT IN MS MUTANTS BUT NOT IN SIB PLANTS; THESE NEW RESTRICTION FRAGMENTS MOST LIKELY AROSE AS THE RESULT OF TRANSPOSITIONAL EVENTS. DURING PHASE I PROGENY OF THESE MUTANTS WILL BE ANALYZED TO DETERMINE WHETHER THESE RESTRICTION FRAGMENTS CO-SEGREGATE WITH MALE STERILITY. ONCE A CO-SEGREGATING FRAGMENT IS IDENTIFIED, DNA FROM THAT MUTANT WILL BE SIZE-FRACTIONATED AND CLONED INTO THE APPROPRIATE LAMBDA VECTOR. IN ADDITION, DURING THE SUMMER MONTHS OF PHASE I A SCREEN FOR NEW TRANSPOSON-INDUCED MS MUTANTS WILL BE SET UP USING TRANSLOCATION STOCKS IN WHICH AC HAS BEEN POSITIONED CLOSE TO THE MS LOCUS BEING TARGETED.