Combination with one or two copies of Mms19EGFP rescues the lethality of Mms19EY00797/Df(3R)ED5147 mutants. Expression of Mms19EGFP in Mms19EY00797 germline mutant females (created using the OvoD technique) at least partially rescues all of the various cell cycle defects (spindle defects, kinked axis of division, many missing nuclei, elongated spindle in metaphase, chromosome segregation defects, and centrosomal defects) observed in their progeny at embryonic division cycle 10-13.