Although siRNAs represent the major class of small RNAs homologous to Penelope, it is evident that this class of small RNA is not efficiently transported from mother to embryo and probably does not play any role in Penelope silencing in the germ line. Intriguingly, in whole mount experiments we were not able to detect Penelope transcription to somatic follicular cells of the ovaries of strain 160, and thereby a subcellular origin of the Penelope-siRNAs remains to be investigated. Collectively, our studies show that two TEs mobilized in dysgenic crosses, namely Penelope and Ulysses, are drastically different, both in transposition behavior in the parental strains, subcellelar compartmentalization of the transposon DAPT transcripts and their processing into small RNAs. It is necessary to mention that we do not rule out the possibility that the causes of occasional transpositions of TEs taking place in the parental strains might be completely different from the causes of much greater mobilization observed in the progeny of dysgenic crosses between these strains. Although, the investigation of transcription levels and cellular distribution of the transcripts do not provide in all cases a straightforward explanation for the observed interstrain specific transpositions of several transposons, the obtained results should be taken into account in further attempts to explain the molecular mechanisms underlying the behavior of various retroviruses and transposons in laboratory and geographical strains, as well as to shed light on D. virilis HD syndrome and the role of co-mobilization of unrelated TEs in this process. Apolipoprotein is the major susceptibility gene for the common late-onset form of Alzheimer‘s disease and the presence of the e4 allele increases the risk of developing AD. Accumulating evidence suggests that the differential effects of ApoE isoforms on Ab aggregation and clearance play a major role in AD pathogenesis. ApoE, a cholesterol carrier, is primarily synthesized in the liver and the central nervous system. ApoE within the CNS is synthesized by astrocytes and microglia. Studies using huAPP transgenic mice that develop an AD-like phenotype have shown that ApoE deletion exerts a beneficial effect on Ab-fibrillogenesis and amyloid plaque formation in the mouse brain without altering Ab-production. APP transgenic mice deficient for ApoE show a dramatic decrease in fibrillary amyloid deposits. ApoE binds to a number of membrane receptors, known as the low density lipoprotein receptor family. Many of these structurally related proteins, including the LDLR and the LDL receptor-related protein 1, have been shown to have diverse roles ranging from cholesterol homeostasis to nervous system development. LDLR, the ancestor gene of the group, has been originally identified as a receptor for cholesterol-rich lipoproteins that regulates LDL-cholesterol metabolism.