FAQs for Research on Genetically Modified (Transgenic) Animals – April 2024

The creation of transgenic rodents falls under one of three sections of the NIH Guidelines depending on the containment level required to house the rodents. Experiments involving the creation of transgenic rodents that can be housed under Biosafety Level 1 conditions are covered under Section III-E-3. Experiments involving the generation of transgenic rodents requiring BL2, BL3 and BL4 containment are covered under Section III-D-4. Experiments specifically involving gene drive modified rodents always require, at minimum, BL2 containment and are covered under Section III-D-8.

The creation of transgenic animals (other than rodents that can be housed under BL1 containment conditions) is covered under Section III-D-4 of the NIH Guidelines. Gene drive modified animals are covered under Section III-D-8. Such animals require a minimum of BL2 containment.

If the technique used to create the knock-out mice involves the stable introduction of recombinant or synthetic nucleic acid molecules into the animal’s genome, the animals will be considered transgenic. As the breeding of two different lines of knock-out animals will potentially generate a novel line of transgenic animal, the work may be covered under the NIH Guidelines and require IBC review and approval. Sections in the NIH Guidelines that cover work with rodents include III-E-3 for work that requires Biosafety Level (BL) 1 containment and III-D-4 for work that requires BL2, BL3 and BL4 containment. If the breeding results in the creation of gene drive modified rodents, such work is covered under Section III-D-8 and requires a minimum containment of BL2. Certain breeding experiments are exempt under Appendix C-VIII of the NIH Guidelines. This exemption covers the breeding of two different lines of transgenic rodents or the breeding of a transgenic rodent and a non-transgenic rodent with the intent of creating a new line of transgenic rodent that can be housed at BL1 if:

1. both parental rodents can be housed under BL1 containment; and
2. neither parental transgenic rodent contains the following genetic modifications:
   • incorporation of more than one-half of the genome of an exogenous eukaryotic virus from a single family of viruses; or
   • incorporation of a transgene that is under the control of a gammaretroviral long terminal repeat (LTR); and
3. the transgenic rodent that results from this breeding is not expected to contain more than one-half of an exogenous viral genome from a single family of viruses.

No, only the purchase or transfer of transgenic rodents that may be maintained at BL1 containment is exempt from the NIH Guidelines. The purchase or transfer of any other animal for research purposes at any biosafety level (including BL1) is not exempt, nor is the purchase and transfer of transgenic rodents that require BL2 or higher containment, which includes any gene drive modified transgenic rodents.

The answer to this question depends on the technique employed in the study. If recombinant techniques are used to knock out the gene, then the work would be covered under the NIH Guidelines.

The generation (creation) of transgenic animals is an activity covered under the NIH Guidelines. The IBC at the institution where that activity is occurring has the responsibility to review and approve that activity (if the institution is subject to the requirements of the NIH Guidelines). The subsequent use of the animals by an investigator not at that institution would need to be reviewed and approved by the IBC at that investigator’s institution if that institution conducts or supports research with recombinant or synthetic nucleic acid molecules, receives NIH support for such research, and the activity is covered under the NIH Guidelines.

An institution’s IBC does not need to review and approve the use of transgenic animals at another institution. If the receiving institution is subject to the NIH Guidelines (i.e. receives NIH support for research with recombinant or synthetic nucleic acid molecules), then the purchase and transfer of animals (other than rodents that can be housed under BL1 containment), along with any experiments subject to the NIH Guidelines, would require review and approval by the IBC at that institution.

When conducting research with recombinant or synthetic nucleic acid molecules in large animals, the work is covered under Appendix M of the NIH Guidelines. Research involving gene drive modified animals, which includes large transgenic animals, requires containment and considerations outlined in Section III-D-8. Appendix M specifies containment and confinement practices when animals are of a size or have growth requirements that preclude the use of laboratory containment of animals. The NIH Guidelines include provisions for tracking and inventorying these animals (Appendix M–1-B-2 states that a permanent record must be maintained of the experimental use and disposal of each animal). Animal carcasses must be disposed of as to avoid their use as food for human beings or animals unless food use is specifically authorized by an appropriate federal agency (Appendix M–1-B-1). An acceptable method, for example, would be incineration.

Research involving gene drive modified organisms (GDMOs), including animals, is covered under Section III-D-8 of the NIH Guidelines. Experiments involving GDMOs must be conducted at a minimum of BL2 containment. More stringent containment may be necessary depending on the outcome of the mandatory risk assessment, which should include assessing the impact on ecosystems. This risk assessment and the containment level determination must be approved by the IBC. The IBC is required to have adequate expertise and training (using ad hoc consultants as deemed necessary) to evaluate GDMO research. This includes a requirement to have a BSO on the IBC.

For further information about the requirements of the NIH Guidelines, please email: NIHGuidelines@od.nih.gov.