mmL1FTE is the oldest full length mouse LINE-1 of which we are currently aware. It is the prototypical old F-type element sequenced by Addy et al., 1994. We searched GenBank for full length LINE-1s and found 2 of about the same age, AC3995a, and AC4407a. Both have old F-type promoters; AC4407a is missing the few hundred bases of its 3' end. Tree construction with a number of other full length LINE-1s places mmL1FTE and AC3995a together in all regions of the sequence, so they are presumed to not be recombinants. AC4407a is recognized to be recombinant with sequences 5' of 5411 mapping partway down the M lineage.
MML1FTE is one of the framework sequences in our skeleton tree for old LINE-1 lineages. AC3995a and AC4407a map to about the same place at informative positions classified in the old skeleton tree. See detail on ftenode region of tree. The branch order of these three sequences should be considered unresolved (see statistics and seq. sources).
A nodal sequence was computed as essentiall y the consensus of these 3 sequences with gaps triaged according to L1MdA2. See alignment. An additional sequence, AC2315b, was added which also maps to the same area and covers the missing portion of AC4407a.
The nodal sequence should be a reasonalbe estimate of what the ancestral LINE-1 of that time looked like. It is intended to stand in for older LINE-1 as the root to trees describing the more recent LINE-1 lineages. It is also intended to provide a better picture of what the old F-type promoter array was like.