Regulatory Interpretation: Interpretation on mRNA Subject to the Select Agent and Toxin Regulations as Outlined in 42 CFR §73.3(c)(2)

It depends.

In accordance with § 73.3(c)(2)(i), mRNA isolated from botulinum neurotoxin producing species of Clostridium are not regulated genetic elements because mRNA itself is incapable of being expressed in vitro or in vivo to produce botulinum neurotoxin.

However, if steps are taken to make mRNA isolated from botulinum neurotoxin producing species of Clostridium capable of being expressed in vitro or in vivo (e.g., packaging* the mRNA for expression in a host, or preparing the mRNA for cell-free protein expression**, or any other manipulation performed to render the mRNA capable of producing the toxin), those products would be regulated genetic elements subject to § 73.3(c)(2)(i).

Additionally, if mRNA from a botulinum neurotoxin producing species of Clostridium is further manipulated for integration into a vector or recombinant host genome and can be expressed in vivo or in vitro, those products would be regulated genetic elements subject to § 73.3(c)(2)(ii).

*Packaging – the use of an enveloping layer, such as a lipid nanoparticle [1], to serves as a delivery platform for the genetic material.
**Cell-free protein expression – any cell-free protocol that is capable of expressing protein from genetic material [2].

It depends.

In accordance with § 73.3(c)(2)(i), cDNA transcribed from mRNA isolated from a botulinum neurotoxin producing species of Clostridium are not regulated genetic elements because cDNA by itself cannot be expressed in vitro or in vivo. Use of this cDNA for fragmentation and additional sequencing would not render the cDNA subject to the select agent and toxin regulations.

However, if the cDNA encodes for the toxic form(s) of any of the toxins listed in § 73.3(b), and steps are taken to make that cDNA capable of being expressed in vitro or in vivo; or if such cDNA is put in a vector or recombinant host genome and can be expressed in vivo or in vitro, those products would be regulated genetic elements or recombinant and/or synthetic nucleic acids subject to § 73.3(c)(2).

Note: Experiments involving the deliberate formation of synthetic or recombinant DNA containing genes for the biosynthesis of a select toxin lethal for vertebrates at an LD[50] <100 ng/kg body weight (including botulinum neurotoxin) may be considered restricted experiments subject to § 73.13. Further guidance regarding restricted experiments can be found in the Federal Select Agent Program Restricted Experiments Guidance document [3].