Ricerc@Sapienza

The maintenance of chromosome ends in Drosophila is an exceptional phenomenon
because it relies on the transposition of specialized retrotransposons rather than on the activity of
the enzyme telomerase that maintains telomeres in almost every other eukaryotic species.
Sequential transpositions of Het-A, TART, and TAHRE (HTT) onto chromosome ends produce
long head-to-tail arrays that are reminiscent to the long arrays of short repeats produced by
telomerase in other organisms. Coordinating the activation and silencing of the HTT array with the

In 1957, Francis Crick speculated that RNA, beyond its protein-coding capacity, could have its own function. Decade after decade this theory was dramatically boosted by the discovery of new classes of noncoding RNAs (ncRNAs), including long noncoding (lnc)RNAs and circular (circ)RNAs, which play a fundamental role in the fine spatio-temporal control of multiple layers of gene expression. Recently, many of these molecules have been identified in a plethora of different tissues and they have emerged to be more cell type specific than protein coding genes.