hypermorphic allele - molecular evidence

Associated with: CG13102⁰⁷⁷¹⁷. Associated with: ms(2)29F⁰⁷⁷¹⁷. It is not known whether the homozygous male sterile phenotype caused by the P{PZ}ms(2)29F⁰⁷⁷¹⁷ insertion is due to an effect on CG13102 or CG9573 (or both).

P{PZ}Rcd-1r⁰⁷⁷¹⁷ is inserted in the 5' UTR of Rcd-1r. It is associated with a recessive male sterility phenotype (associated with allele ms(2)29F⁰⁷⁷¹⁷), and affects the transcription of both Rcd-1r (associated with allele Rcd-1r⁰⁷⁷¹⁷) and the neighbouring gene CG13102 (associated with allele CG13102⁰⁷⁷¹⁷). Male flies heterozygous for P{PZ}Rcd-1r⁰⁷⁷¹⁷ and a deficiency uncovering the insertion site (Df(2L)N22-14 or Df(2L)Exel6021) are fertile, suggesting that the male sterility is not caused by the P{PZ} insertion. However, homozygosity for P{PZ}Rcd-1r⁰⁷⁷¹⁷ causes mis-expression of the testis-specific Rcd-1r gene and the production of dsRNA corresponding to the overlapping region of Rcd-1r and CG13102 which may have an RNAi effect on either mRNA. Thus, mis-expression of Rcd-1r and/or RNAi-mediated knock-down of Rcd-1r/CG13102 at sufficient levels (ie. in homozygotes) could be the basis for the recessive male sterility. In summary, it is currently unclear whether or not the P{PZ}Rcd-1r⁰⁷⁷¹⁷ insertion is the cause of the male sterility associated with the chromosome.