Dynamic changes of telomeric restriction fragment (TRF) lengths in cells during the developmental process from embryos to seedlings and a comparison with the embryonal calli in Ginkgo biloba L.

Telomeres are the structures that locate at the terminals of linear eukaryotic chromosomes. They can play essential roles in many cellular processes. The terminal location of Arabidopsis -type TTTAGGG tandem repeats were thought to be highly conserved. The terminal location of Ginkgo biloba L. consisting of TTTAGGG tandem repeats, were confirmed by Bal 31 exonuclease degradation and Southern blotting. By comparing telomeric restriction fragment (TRF) lengths at different developmental stages from embryos to seedlings, a fluctuant tendency towards variation was found in these samples. The TRF length of embryos was also compared with that of embryonal calli and an upward trend was discovered in callus culture. The results suggest that there should be a telomerase mechanism or/and ALT mechanism for the maintenance of telomere length.