OmniBank FAQ's
Frequently Asked Questions- How do I find an OmniBank clone with a mutation in my gene of interest?
- How are the mutations in OmniBank made?
- Do gene trap insertions disrupt gene function?
- What is the germline transmission rate of your ES cell clones?
- Are all OmniBank clones available for purchase?
- What materials and information will I obtain with my OmniBank mouse line?
- What are the terms for obtaining OmniBank mouse lines?
To search the OmniBank database with your gene of interest, click here.
2. How are the mutations in OmniBank made?
The OmniBank mutations are created using insertional mutagenesis. The insertion vectors are based on our proprietary retroviral-based gene trap technology, which was first published in April 9, 1998 issue of Nature, Vol. 392. The viruses deliver a gene trap construct to the ES cells that allows the expression of a promoter-less selectable marker gene when the vector has inserted into and trapped exons from a gene. We have developed a proprietary series of VICTR (Viral Construct for Trapping) gene trap vectors, an example of which is illustrated in Figure 2.
The ultimate proof of gene trap mutagenicity is the disruption of transcript and resulting phenotypes of gene trap lines of mice. As part of our Quality Control (QC) process, we obtain the precise genomic insertion site of the retroviral vector through inverse genomic PCR. With the completion and assembly of the mouse genome sequence, these insertion sites are easily mapped to their precise location within the mutated gene. We perform this on every clone prior to microinjection. Analysis of non-embryonic lethal OmniBank mouse lines by this method shows that a retroviral insertion within the gene of interest leads to the disruption of the native mRNA transcript in more than 99% of cases, as measured by RT-PCR using primers complementary to exons flanking the retroviral vector. As depicted in Figure 2, OmniBank insertions generate a fusion transcript between the upstream exons of the endogenous gene and a selectable marker. An insertion towards the 3' end of the coding region in a gene could potentially generate a functional fusion between the endogenous protein and the selectable marker protein. In our experience, 3' retroviral insertions often lead to transcript instability and are usually mutagenic. The fusion transcript generated from the PGK promoter between the vector and the downstream exons of the gene is designed to contain stop codons in all reading frames and not produce any endogenous protein. OmniBank contains multiple hits at different integration loci for many genes, thereby providing an even higher degree of assurance that a mutagenic event will be present and identified using QC for any one gene.
4. What is the germline transmission rate of your ES cell clones?
For the resource to be useful, a high percentage of ES clones must populate the germline of chimeric mice. Based on our experience, we believe we can maintain a germline transmission rate exceeding 80%. It is important to note that, for many genes, the library contains multiple hits, thus assuring a high probability of germline transmission.
5. Are all OmniBank clones available for purchase?
In an effort to balance the demand from the broader scientific community with the needs of our corporate partners and our internal development efforts, we make available for purchase by academic researchers a large majority of OmniBank mouse lines. In order to verify that a requested OmniBank mouse line is available under this program, each request will be promptly reviewed by a Lexicon scientist at the time of submission.
6. What materials and information will I obtain with my OmniBank mouse line?
You will receive the precise genomic insertion site of the gene-trap vector.
7. What are the terms for obtaining OmniBank mouse lines?
We make mouse lines available under our OmniBank e-Biology program pursuant to the standard terms contained in our e-Biology Material Transfer Agreement. These mouse lines are available at fees starting at $30,000, depending upon the contract options selected. Due to commercial proprietary obligations, mouse lines for certain OmniBank embryonic stem cell clones may not be available under this program. Mouse lines made available under our OmniBank e-Biology program are intended for non-commercial research use only and may not be used in connection with any sponsored research program with a for-profit third party.
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