Fig. 4.

Copy number of recently inserted mysTR elements in eight rodent species. The pro/pol domains of selected mysTR elements were hybridized to dot blots of genomic DNA from the following L1-inactive (L1⁻) and L1-active (L1⁺) species: C. callosus (Ccal), A. boliviensis (Abol), O. palustris (Opal), N. spinosus (Nspi), S. hispidus (Shis), P. maniculatus (Pman), R. fulvescens (Rful), and N. sumichrasti (Nsum). The copy number of a typical endogenous retrovirus (ERV) is noted with an arrow to the right, as is the copy number of mouse IAP elements, one of the most numerous ERVs previously known in a mammalian genome.