Just an interesting locus…
The genes T12A7.5 and H01G02.3a (and b) have a 3 Kb overlap at their 3’ ends.
These appear to be correct gene structures.
I’ve not looked for other examples of long overlaps, but I would bet that this is not the longest gene overlap in the genome.
Overlapping genes probably are involved in regulating each other by RNAi - search for ‘natural antisense transcripts’ in the literature.