The piOxi DB is a repository of piwi-interacting RNA (piRNA) sequences from germline and somatic tissues detected solely via oxidation by sodium periodate treatment. This comprehensive database annotates piRNA according to its genomic position.

piOxi DB contains the following features:
• piRNA detection by sodium periodate treatment (β-elimination), size selection, and sequencing.
• Inclusion of tissues from germline and soma-derived lineages for tissue-specific piRNA comparisons.
• Inclusion of data from several species to identify piRNA based on evolutionary conservation.
• piRNA stratification by sex, based on data availability.
• Annotations for transposable elements and mRNA targets to survey piRNA association to potential epigenetic regulatory elements.

Mature mammalian germline piRNAs typically consist of 24-32 nucleotides, with a strong preference for a 5ʹ uridine signature and a 2’-O-methylation modification at their 3’ ends. In mice, piRNAs interact with the PIWI-like proteins Piwil1, Piwil2, and Piwil4, and participate in a variety of biological functions, including piRNA biogenesis. In the current release, M. musculus male-specific piRNAs are derived from this study, which includes tissue-specific piRNA data derived from the same individuals (N=2), during adulthood (2-3 months of age). Therefore, the current database contains piRNAs that range 20-45 nucleotides in length, from five mouse tissues (i.e. cortex, hippocampus, liver, kidney, and testis) representative of the three germ layers. See here to find the length distribution of all mouse piRNAs and tissue compositions.

In the current release, all macaque piRNAs are derived from this study, with the data generated using two M. fascicularis ovary samples obtained from animals at 21 and 9 years of age. See here to find the length distribution of macaque ovary piRNAs and tissue compositions.

In humans, piRNAs interact with PIWI-like proteins PIWIL1, PIWIL2, PIWIL3 and PIWIL4 to carry out a variety of functions. Together, the PIWIL proteins form the critical machinery for piRNA biogenesis and function. In the current release, all human piRNAs are derived through preliminary data generated from Morgan et al 2023. The data includes the comprehensive sex-specific (N=5 males and 5 females) analysis of six H. Sapien tissues (i.e. brain, lung, heart, liver, kidney, and gonads), collected during development (gestational days 90-105). See here to find the length distribution of all human piRNAs and tissue compositions.