Feeding RNAi with 150bp genomic piece

Model Organism: Worms Methods & Reagents
1

Hi,
I am trying feeding RNAi with 150bp genomic DNA sequence, which covers 105bp of the coding region in a gene of interest. Will that be too small to work for RNAi? Anybody has experience on similar RNAi tests?

Thanks,

2

Andy Fire published a paper on this topic in 2000.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WSR-41V33K2-B&_user=443835&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000020958&_version=1&_urlVersion=0&_userid=443835&md5=4d21915eefd116c4d84e7b2578ef4ed4

Some one said: when inject your dsRNA, you can even see the phenotype at 20-30 nt. However, when RNAi by feeding, it is preferable to use a bigger chunk longer than 250 nt.
The shortest one I tested is 300 nt and works great.

shouhong

3

Definitively your are close to the limit. In my experience it depends on the targeted gene. To optimize your efficiency, you may check if the ORFeome RNAi library has a RNAi clone for your gene, since those RNAi clones contains only coding sequences of the targeted gene. Otherwise you could make that RNAi clone yourself.
Optionally, RNAi hypersensitive strains seems to be gene specific for its hypersensitivity, so you may check a panel of those.
In any case, to get the final answer about how effective is your RNAi, you should make a RT-PCR.
Good luck !!

4

recently, I have RNAi the eri-1(mg366) strain with a 57bp dsRNA by feeding experiment. It still works great.