Piwi-interacting RNAs (piRNAs) are the largest class of single stranded, small non-coding RNAs of about 26-32 nucleotides in length. piRNAs interact with the Piwi (P-element Induced Wimpy Testis) subfamily of Argonaute proteins. The Piwi subfamily comprises Piwi, Aubergine and AGO3 in flies, MILI, MIWI and MIWI2 in mice, and HILI, HIWI1, HIWI2 and HIWI3 in humans. Individual piRNAs are very diverse and are poorly conserved even between closely related species. In contrast to several hundred microRNA species, tens of thousands of unique piRNA sequences are known in human, mouse and rat.piRNAs are strikingly different from microRNAs in their length, expression pattern, genomic organization and biogenesis.
Arraystar's scientists have developed piRNA microarrays for human, mouse and rat species to evaluate the global expression of piRNAs. The piRNA sequences from all three organisms are downloaded from the NCBI database, and mapped to the genome sequences (HG19, MM9 and RN4) using UCSC Blat. Antisense 60-mer oligonucleotide probes are designed using a duplex method. Our piRNA arrays (table 1) sensitively and accurately profile the expfression of piRNAs.
• Comprehensive collection and reliable selection of piRNA sequences.
• 60-mer oligonucleotide probes using duplex design to achieve high specificity.
• Duplicated probes for most of the piRNAs.