19 Aug 99 webmaster

Could a bee sting cause scrapie? Yes, indeed -- there was an apparent near miss 23.6 million years ago in a common ancestor of sheep and cow -- a retrotransposon event that might have boosted prion protein production to levels fostering sporadic TSE.
Ruminants contain a 1220 bp mariner retrotransposon in their 3' UTR portion of their mRNA. This element, with its terminal inverted repeats, are described by Lee as a fossil transposase pseudogene with homology to the Mellifera (bee) subfamily. It is probably an old insertion shared by all ruminants since it has 7-8 frameshifts and 5 stop condons -- figure 3 of the Lee paper shows a guided translation and the correct flanking human gene alignment. The insertion in cow/sheep occured between 27587 and 27588 in terms of human 3' UTR numbering, just downstream of the Bov-tA3, greatly increasing the length of ruminant mRNA.