TTAGG telomeric repeats in chromosomes of some insects and other arthropods

We studied the occurrence of the TTAGG telomere repeats by fluorescence in- situ hybridization (FISH) and Southern hybridization in ten insect species and two other arthropods. (TTAGG)(n)-containing telomeres were found in thr ee Lepidoptera species, the silkworm Bombyx mori (in which the telomeric se quence was recently discovered), the flour moth Ephestia kuehniella, and th e wax moth Galleria mellonella, in one species of Hymenoptera, the honey be e Apis mellifera, in one species of Coleoptera, the bark beetle Ips typogra phus, in one species of Orthoptera, the locust Locusta migratoria, and in a crustacean, the amphipod Gammarus pulex. They were absent in another speci es of Coleoptera, the mealworm Tenebrio molitor, two representatives of Dip tera, Drosophila melanogaster and Megaselia scalaris, a species of Heteropt era, the bug Pyrrhocoris apterus and a spider, Tegenaria ferruginea. Our re sults, which confirm and extend earlier observations, suggest that (TTAGG)( n) was a phylogenetically ancestral telomere motif in the insect lineage bu t was lost independently in different groups, being replaced probably by ot her telomere motifs. In the Coleoptera this must have happened rather recen tly as even members of the same family, Curculionidae, differ with respect to the telomeric DNA.