Table 1 The details of RNAi accessory genes duplicated in the obscura group as reported by Palmer et al. [23]
Gene | Involvement in piRNA pathway | Function of the protein product | Tissue expression in Dmel | Reference |
|---|---|---|---|---|
armitage (armi) | piRNA biogenesis | A RNA helicase which unwinds the piRNA intermediates before loading into Piwi | ubiquitously expressed, highest in ovary | [30] |
[31] | ||||
asterix (arx) | TGS (Transcriptional Gene Silencing) | A zinc-finger protein which directly interacts with Piwi to scan and identify the transposon transcriptions as target for histone modifications | ubiquitously expressed, highest in ovary | [32] |
[33] | ||||
cutoff (cuff) | piRNA transcription | Forms a complex with Rhino-Deadlock-Cutoff (Rhi-Del-Cuff) to protect uncapped non-canonical (dual-strand cluster) piRNA transcript from degradation, splicing and transcription termination | testis | [34] |
maelstrom (mael) | TGS | Act downstream of Piwi to establish histone modification and prevent the spreading of the silencing marker to the surrounding genes | brain, testis, adult female salivary gland, ovary | [35] |
tejas (tej) | Secondary piRNA production (Ping-pong cycle) | A Tudor-domain protein which physically interact with Vas, Spn-E and Aub for a proper ping-pong cycle in the nuage | testis, accessory glands, adult female salivary gland, ovary | [36] |
vreteno (vret) | piRNA biogenesis | A Tudor-domain protein which essential for an early primary piRNA processing | larval brain, adult female salivary gland, ovary, testis | [37] |