Lack of genetic conservation between two different varieties of maize. Note that they differ not only by the number of retrotransposon insertions, but McC has 4 genes not present in B73. These are Cdl1, Hypro2, Hypro3, and Rlk, in segment 58-68.
Source: Fu, H.H., and H.K. Dooner. 2002. Intraspecific violation of genetic colinearity and its implications in maize. Proc. Natl. Acad. Sci. USA 99:9573-9578.