Using the RNAi phenotypes of paralogous genes in C. elegans, we devised a strategy to estimate the minimum degree of similarity needed to observe off-target effects.
If such pairs exhibit a high likelihood of off-target cross-reaction, it suggests that having 100% identity over 25 nt is sufficient to observe off-target effects.
On the other hand, if this likelihood is low, it suggests that having 100% identity over 25 nt is not sufficient to observe off-target effects.
More precisely, we calculated the minimal length over which sequence similarity is necessary to have a high likelihood to observe off-target cross-reaction.
Moreover, we would like to mention that our results are based on the assumption that only one stretch of high similarity is necessary to observe off-target reaction.
Although these experiments give some indication of the sequence identity requirement, the question of how much similarity over how much length is necessary to observe off-target cross-reaction remains open.
We did observe off-target MV infection in a small population of neurons from the treated mice, but these were unaccompanied by signs of inflammation, neuronal death, or any symptoms of neurotoxicity in the animals prior to their sacrifice.
To compute more precisely the minimum length on which a high identity is necessary to observe off-target cross-reaction, we applied the same strategy to compare 25 nt with 30 nt, 30 nt with 40 nt, etc. Results (Table 1) show that the data fit well the model (i.e. P > 0.3) for pairs with high identity on 40 nt only (not on 30 nt or on 50 nt).
These days, however, the tradition established by Spiridon Belokas is observed off the Olympic stage.
In 2009, the BBC reported that a mushroom coral, Fungia scruposa, was observed off the coast of Israel feeding on an adult moon jellyfish approximately its own size.
Observing off to the side was the actor Robert De Niro, one of the presenters of the event along with Michael Douglas and Morgan Freeman.
