TABLE 2.
Survey of piRNA Sequencing and Mapping Data Across Animal Phylogeny
| Organism and Tissue |
% Repetetive Sequence in Genome |
Sequenced piRNAs |
% piRNAs mapping to transposons* |
% mapping to coding genes |
Ping pong signature |
References |
|---|---|---|---|---|---|---|
| Fly Ovary | 10% Sela et al., 2010 |
Piwi | 77% | ~5% | Yes | Brennecke et al., 2007 |
| Aubergine | 68% | ~5% | ||||
| Argonaute 3 | 78% | ~1% | ||||
| Fly Testis | Aubergine | 7% | 0.5% | Nagao et al., 2010 | ||
| Argonaute 3 | 54% | 4% | ||||
|
Fly Cultured Somatic Ovarian Cells |
Piwi | 54% | 17% | No | Saito et al., 2009 | |
|
Mouse, Adult Testis |
37.5% Waterston et al., 2002 |
MIWI | 17% | ~1–2% | No |
Girard et al., 2006; Aravin et al., 2006; Grivna et al., 2006a |
| MIWI | 15% | |||||
|
Mouse, 10 dpp Testis |
MILI | 35% | 29% | Yes | Aravin et al., 2007b | |
|
Mouse, 16.5 dpc Fetal Testis |
MIWI2 | 76% | ~1–2% | Yes | Aravin et al., 2008 | |
| MILI | 46% | 5% | ||||
|
Zebrafish Ovary |
26% Sela et al., 2010 |
Ziwi | 48% | 16% | Yes | Houwing et al., 2008 |
| Zili | 36% | 17% | ||||
|
Zebrafish Testis |
Ziwi | 32% | 22% | |||
| Zili | 23% | 19% | ||||
| Frog Oocyte | ~33% Hellsten et al., 2010 |
Xiwi | 23% | 19% | Yes (Total small RNA sequencing) | Lau et al., 2009 |
| Nematode | 9% Sela et al., 2010 |
PRG-1 | 21U RNAs map to two large genomic clusters, not tranpsoson-enriched |
No |
Batista et al., 2008; Das et al., 2008 |
|
| Rat Testis | ~40% Gibbs et al., 2004 |
RIWI | 20% | ~1% | Unknown | Lau et al., 2006 |
| Planarians | 31% Friedlander et al., 2009 |
Putative | 32% | Unknown | Yes | Friedlander et al., 2009 |
| Sea Anemone | 25% Putnam et al., 2007 |
Putative | Unkno | wn | Yes | Grimson et al., 2008 |
| Sponge | 20–30% Erpenbeck et al., 2012 |
Putative | Unkno | wn | Yes | Grimson et al., 2008 |
*
Mapping of piRNAs to transposon sequences is more difficult in animals with poorly-annotated genomes, and the reader should check references to determine how these data were obtained.