P{lacW} inseted into large, second, intron of Trl, within 500bp of the P{bluetail} insertion in Trl13C.
Mutant for female meiotic segregation: 3.6% X chromosome exceptions from X/X females. 1.5% 4th chromosome exceptions from X/X females. 32.2% X chromosome exceptions from X/Bal females. 2.7% 4th chromosome exceptions from X/Bal females. Shows high levels of X nondisjunction but low levels of 4th chromosome nondisjunction. Primarily affects achiasmate chromosome segregation.