FISH evidence for a high evolutionary conservation in snakes of an interspersed repeated DNA sequence

A repeated DNA sequence, named RepHv-390, isolated from DNA samples of male and female specimens of the European Western wipe snake, Hierophis viridiflavus, was used as probe for FISH analysis to detect its distribution on chromosomes of this colubrid species and of other species of the same and of different snake families. We observed positive results in all the studied species, namely: H. viridiflavus, Coronella austriaca, Elaphe quatuorlineata (Colubridae), Phisalixella variabilis (Lamprophiidae) and Vipera aspis (Viperidae). Intense and abundant hybridization signals of RepHv-390 were observed on all chromosomes of H. viridiflavus, C. austriaca, E. quatuorlineata and V. aspis and on nuclei of P. variabilis. Its wide presence on the chromosomes of all the studied species suggests that RepHv-390 is a segment of transposable element (TE) of ancient origin in snakes. Probably, the ancient TE arose in a common Colubroidea ancestor before the diversification into different lineages of this superfamily. Preliminary analysis of RepHv-390 evidenced no significant identity with any other known sequence, suggesting that RepHv-390 is a segment of an unclassified TE element