Visna-maedi virus
Visna virus ( also known as Visna-maedi virus , Maedi-visna virus and Ovine lentivirus ) from the genus "Lentivirus" and subfamily "Orthoretrovirinae" , is a "prototype" retrovirus that causes encephalitis and chronic pneumonitis in sheep . 
<triplet> genus <subj> subfamily <obj> part of <triplet> Lentivirus <subj> Orthoretrovirinae <obj> parent taxon