Why clone flies? Using cloned Drosophila to monitor epigenetic defects.

Since the birth of the first cloned sheep in 1996, advances in nuclear transplantation have led to both the creation of genetically tailored stem cells and the generation of a number of cloned organisms. The list of cloned animals reared to adulthood currently includes the frog, sheep, mouse, cow, goat, pig, rabbit, cat, zebrafish, mule, horse, rat and dog. The addition of Drosophila to this elite bestiary of cloned animals has prompted the question - why clone flies? Organisms generated by nuclear transplantation suffer from a high rate of associated defects, and many of these defects appear to be related to aberrant genomic imprinting. Imprinted gene expression also appears to be compromised in Drosophila clones. Proper imprinted gene regulation relies on a suite of highly conserved chromatin-modifying genes first identified in Drosophila. Thus, Drosophila can potentially be used to study epigenetic dysfunction in cloned animals and to screen for genetic and epigenetic conditions that promote the production of healthy clones.