Selumetinib Deception You Have Been Assured Around

Матеріал з HistoryPedia
Перейти до: навігація, пошук

Posterior localization of both proteins is disrupted in uap56sz15��/uap5628 mutants ( Meignin and Davis, 2008) ( Figures S3B and S3C). Posterior localization?of click here Aub was restored in mutants expressing the wild-type UAP56-Venus transgene but not in mutants expressing the sz-Venus fusion ( Figure?S3C). We did not assay Vas localization in these transgenic ovaries, but Aub localization to pole plasm requires Vas ( Harris and Macdonald, 2001), suggesting that Vas localization is also restored. The E245K substitution thus disrupts the organization of nuclear and cytoplasmic components of the piRNA biogenesis machinery. piRNA pathway mutations lead to germline DNA damage, which is proposed to result from transposon mobilization (reviewed by Klattenhoff and Theurkauf, 2008). ��H2Av is a phosphorylated histone variant that accumulates at DNA break sites (Madigan et?al., 2002). In wild-type egg chambers, ��H2Av foci are present in region 2 of the germarium, where meiotic breaks form, and in later nurse cell nuclei undergoing NAD endoreduplication (Jang et?al., 2003). Stage 2 and later oocyte nuclei, by contrast, are consistently negative for ��H2Av foci. In uap56sz15��/uap5628 mutants, ��H2Av foci persist in oocyte nuclei and appear to be enhanced in the nurse cells ( Figure?S4A). In uap56sz15��/uap5628 mutants expressing the wild-type UAP56-Venus transgene, by contrast, ��H2Av foci were not detected in later stage oocytes ( Figure?S4A). UAP56 is therefore required to maintain germline genome integrity. UAP56 is required for splicing and export of a broad spectrum of mRNAs (Gatfield et?al., 2001; Shen, 2009) but our phenotypic and localization data raised the possibility that UAP56 also functions with Selumetinib ic50 Vas and Rhi to control transposon activity. We therefore used whole-genome tiling arrays to assay gene and transposon expression in uap56sz15��/uap5628 and vas mutant ovaries and compared these data with an earlier analysis of rhi mutants ( Klattenhoff et?al., 2009). The vasa intronic gene (vig) is contained in a vas intron, and Vig copurifies with FMRP and components of the siRNA machinery ( Caudy et?al., 2002), suggesting that it functions in RNA silencing. To specifically disrupt vas, we therefore analyzed a null deletion allele that removes both vas and vig in trans to a point mutation in vas that does not disrupt vig. The Genome Brower screen shot in Figure?4 shows expression of the retrotransposon Blood and neighboring Ent1 gene, which contains three introns in control and uap56, rhi, and vas mutants. In all three mutants, Blood is overexpressed and Ent1 is expressed at levels comparable to the control ( Figure?4A). This pattern extends across the genome because no protein-coding gene showed a statistically significant difference from wild-type in uap56, vas, or rhi mutants (FDR?