Genomic fragment containing endos.
endos+tRa/endos[+] is an enhancer | maternal effect of female semi-sterile | dominant phenotype of gwlscant, polo[+]/polo1
endos+tRa/endos[+], gwlscant, polo[+]/polo1 has female sterile | dominant phenotype
endos+tRa enhances the reduced fertility phenotype of polo1/+ gwlscant/+ double heterozygous females, such that in each case the triple heterozygotes are completely sterile.