Three researchers(*) at the Graduate School of Science, Osaka University found a first example of DNA interference phenomenon in multicellular animals using marine plankton Oikopleura dioica. RNA-induced gene silencing system is well known as RNA interference(RNAi) in a wide range of eukaryotes. On the other hands, DNA-induced gene silencing system, known as DNA interference(DNAi), has been only found in a few species of plants, ciliates and archaea and has not been found in multicellular animals.

To examine the effect of DNAi in Oikopleura diocia, these researchers introduced PCR fragments encoding Brachyury gene into O.dioica and found that this decreased the amount of mRNA sequence specifically and induced tail malformation reminiscent of RNAi-mediated gene knockdown phenotype of Brachyury. This gene knockdown was induced not only by PCR fragment covering coding region of Brachyury gene but also 5′-flanking region and intron.

Therefore they found a first example of DNAi in multicellular animals. This phenomenon can be applied for a new gene knockdown method for characterization of gene functions.

(*) Tatsuya Omotezako, PhD student, Takeshi Onuma, Assistant Professor, Hiroki Nishida, Professor.

Oikopleura dioica(Adult)

(Link) http://resou.osaka-u.ac.jp/en/research/2015/20150518_1