Table 1.

Repeat Insertions in the PrPLoci

Total
SINEs LINE1 other LINEs DNA trans LTR elements Other Total
Human1811.5%611.7%46.5%73.4%47.1%00.0%3940.2%
Mouse3213.3%59.5%22.7%41.7%109.8%13.6%5340.4%
Sheep125.9%413.1%910.8%66.1%320.3%10.7%3457.1%
Order specific (young)
Bov-B Total young
Human1510.8%35.7%00.0%11.3%12.5%00.0%2020.2%
Mouse2912.5%23.2%00.0%00.0%87.5%13.6%3926.7%
Sheep105.2%17.1%55.9%13.9%218.5%10.7%1941.3%
Shared (old)
SINEs (MIR) LINE1 LINE2 Total old
Human30.7%36.0%46.5%62.2%34.7%00.0%1920.0%
Mouse30.8%36.2%22.7%41.7%22.3%00.0%1413.7%
Sheep20.7%36.0%44.9%52.3%11.8%00.0%1515.7%

[i] Character of the insertions in the PrP loci. Almost all are insertions of SINEs, LINEs, retrovirus-like elements, and DNA transposons (see Smit 1996). The two exceptions are a laminin receptor mRNA that retroposed in the mouse locus, and the unclassified interspersed repeat MER21 in the sheep locus. Listed are the number of copies of these elements in the three PrP loci and the fraction of these loci they comprise (mouse DNA limited to the region for which the human orthologous region is known). The data have been subdivided in order-specific elements, which are only found in one species, and elements that are shared between species, representing the offspring of transposable elements that were active after and before the mammalian radiation, respectively. The mouse data do not include the IAP insert in the Prnp a allele. With the IAP, it brings the total transposon-derived fraction to 52%.