From: An old weapon with a new function: PIWI-interacting RNAs in neurodegenerative diseases
 | C. elegans | Drosophila | Mouse | Human | Reference |
---|---|---|---|---|---|
Size | 21 nt | 23-29 nt | 24-30 nt | 26-32 nt | |
Structure | 5′ Uridine 3′ 2′-O-methylation | 5′ Uridine 3′ 2′-O-methylation | 5′ Uridine 3′ 2′-O-methylation | 5′ Uridine | |
PIWI proteins | PRG-1 | Piwi Aub Ago3 | MIWI (PIWIL1) MILI (PIWIL2) MIWI2 (PIWIL4) | HIWI (PIWIL1) HILI (PIWIL2) HIWI3 (PIWIL3) HIWI2 (PIWIL4) | |
Transcription loci | Type I loci, Type II loci, mainly from chromosome IV | flamenco loci, 42AB loci, distributed across all chromosomes | Distinct intergenic loci, distributed across all chromosomes | Distributed across 22 autosomal chromosomes and X chromosome | |
Amplification | RdRp | Ping-pong cycle | Ping-pong cycle | Ping-pong cycle | |
Biogenesis factor | FKH transcription factors, TOFU genes, PRG-1, EGO-1 | RDC complex, MitoPLD/Zuc, TDRD proteins, PIWI proteins | A-MYB transcription factor, MitoPLD/Zuc, TDRD proteins, PIWI proteins | PIWI proteins | |
Downstream effects | RNA degradation, histone modification, 22G-RNA biogenesis | RNA degradation, histone modification | RNA degradation, histone modification, DNA methylation | RNA degradation, histone modification, DNA methylation |