ZeGenesis – Genetic Services


antisense-oligonucleotides-icon Antisense oligonucleotides-based knock-down

ZeClinics’ knock-down (KD) approaches are a fast and very easy way to see if your gene of interest might have a phenotype (reverse genetic analysis), and warrant making a germline mutant.

Our genetic experts can generate functional KDs of gene expression in F0 animals using antisense oligonucleotides (ASOs). This procedure does not compromise the genomic DNA but alters the transcribed mRNA.

Transient gene KD will help establish a direct link between the biochemical function of a gene product and its role in vivo. Phenotyping is possible with good controls but the decreasing concentration of ASOs leads to sub-optimal KD usually by 4dpf.

ASO-based Knock-down

Looking for a fast strategy to find what phenotypes are controlled by your genes of interest?

The main difference of this technique compared to other alternatives for fast target validation, such as Crispants, is the transient nature of the genetic modulation.



  • Rapid and economic technique for reverse genetic analysis: seeking to find what phenotypes are controlled by particular genes.
  • Fast target validation: screening of several candidate genes.


Scalable solution: high throughput screening of multiple candidate genes

Confirmation of the phenotypic output before establishing the KO line

Non-invasive, in vivo readouts to detect KO-induced phenotypes at the level of cells, tissues or organs

Method description

ASOs are RNA-DNA hybrid oligonucleotides binding the target mRNAs to induce their degradation via RNAse H or interfere with their maturation/translation. The resulting phenotypes are transient, as larvae tend to recover as ASOs get degraded. For this reason, ASOs-based approaches are better suited to study phenotypes arising during the early stages of embryonic development.

Figure 1. Transient KD is induced by the injection of ASOs into one-cell-stage embryos. The levels of ASOs in zebrafish tissues decrease over time upon injection.


Results of the phenotypic analysis according to customers' interests and needs:

  • Teratogenic phenotypes
  • Organ-specific morphological or functional defects (heart-specific, liver-specific, etc.)
  • Behavioral phenotypes

We'd like to hear from you

If you want more information about our ASO-based
knock-down services or have any other questions,
please contact our experts.


  1. Pauli A, Montague TG, Lennox KA, Behlke MA, Schier AF. Antisense Oligonucleotide-Mediated Transcript Knockdown in Zebrafish. PLoS One. 2015 Oct 5;10(10):e0139504.