March 2012 Update: The latest pig specific array is based on miRBase version 18 and features all 255 unique mature miRNAs. You can download the full sequence list here: pig miRNA array probe content.
Houston, TX, – LC Sciences LLC., the worlds first miRNA array service provider, today anounced a new miRNA array layout focusing on researchers using pig animal models. With the recent update of the miRNA data base miRBase to version 12.0 the number of known and validated miRNA sequences for pig (Sus scrofa) doubled. Currently miRBase 12.0 lists 66 precurcor sequences which result in 64 mature pig miRNAs.
Of these 64 sequences 9 are unique for pig, 32 are identical to human, 16 to gorilla, 2 to pygmy chimpanzee, 2 to rat, 2 to platypus, and 1 is identical to common chimpanzee.
Depending on the goal of the experiment you can either chose a chip design with all 64 mature pig miRNA sequences (pig miRNA array chip) or based on the sequence conservation above a new customized pig/hominidaen/rat array. The later offers the option to get leads for additional conserved miRNA sequences.
A general downside of chips with multi-species probe content is the fact that it is difficult to interpret the data: i.e. you use pig samples and get a signal for a human miRNA sequence: is this miRNA sequence really present in pig or is it cross-hyb to a similar sequence? This is why it makes much more sense to use single species chips when it comes to well characterized species like human, mouse or rat.