Eye colour: w gene is active in anterior cells of the eye.
wtsh-J834 has abnormal eye color phenotype, enhanceable by GugS2/Gug[+]
wtsh-J834 has pigment cell phenotype, enhanceable by GugS2/Gug[+]
GugS2 dominantly suppresses expression of the w gene in the P{lacW}J834 line.