TABLE 6

Dominant-lethal synergism with mutations in dl and twi as a test for the involvement of sc in mesoderm formation

% viabilityb relative to the Cy male “no transgene” reference class (n)
scx/sc+ femalessc+/Y males
Cy+: all twi/+Cy: 50:50 +/+ and twi/+Cy+: all twi/+Cy: 50:50 +/+ and twi/+
CrossaTemperatureNo transgene (%)P(sisB+)/+ (%)No transgene (%)P(sisB+)/+ (%)No transgene (%)P(sisB+)/+ (%)No transgene (n)P(sisB+)/+ (%)
1. scx = scM625°0.90.7578376(843)101
22°101982893846(324)114
18°677398965583(225)91
2. scx = sc+25°0.60.3838747(696)104
22°264195913954(265)98
18°951271271399189(150)116
  • a wL118;dl1cn sca/CyO virgins × males: (1) scM6 w/Y; cn twi1bw sp/CyO; P(sisB+w+mC}B5#10/+ or (2) w/Y; cn twi1bw sp/CyO; P{sisB+w+mC}B5#10/+. The sisB+ transgene is described in Erickson and Cline (1991). Males for these two crosses were brothers from a stock that had been maintained with scM6/sc+ mothers for four generations to randomize genetic background.

  • b For Cy classes, the full Cy reference number is used for the calculation, while for the Cy+ flies, the 100% value is calculated as 50% of the reference Cy class. Since that reference class includes both +/+ and twi/+, this viability estimate will be approximately double the true value when the viability of twi/+ flies is low relative to their +/+ sibs; as viability increases, the estimate will more closely reflect the true relative viability value.