This project focuses on a novel method of biocontrol for common carp, which will complement existing technologies by introducing a synthetic species-like barrier to reproduction. MAISRC researchers will use programmable transcription activators to cause lethal overexpression of natural genes in hybrid embryos, preventing their development.
MAISRC researchers are developing a synthetic incompatibility method that could control populations of pest or invasive species and prevent genetically modified aquatic organisms from spreading transgenes to wild populations. This technique involves genetically altering males of the invasive species and releasing them into the wild, resulting in sterile offspring and eventual population control. This method shows promise as a species-specific, broadly applicable, and cost-effective solution for population control.
Phase III: Current phase
MAISRC researchers aim to build on their success in Phase II by characterizing several genetic biocontrol methods for common carp, including sterile release, sex-biasing, and gene drive. They will explore innovative methods to accelerate genetic engineering in diverse non-model species and will act on previous social engagement learnings by defining and demonstrating a model techno-social analysis for carp biocontrol. The specific objectives include:
- Quantitatively characterizing the performance of sex-ratio biasing and gene drive in carp, and continuing to engineer genetic incompatibility in common carp.
- Developing improved surrogate host technology for black carp, silver carp, and grass carp.
- Performing a techno-social analysis (TSA) for carp genetic biocontrol.
Phase I
Project manager: Michael Smanski
TImeline: 2016-2018
The foraging habits of the invasive common carp, Cyprinus carpio, degrade water quality, reduce vegetative cover and waterfowl numbers, and diminish the ability of lakes to absorb nutrients from agricultural runoff. Current control methods have been insufficient, necessitating improved strategies. The overall goal of this phase by MAISRC researchers is to demonstrate a novel approach for controlling aquatic invasive species using invasive carp as a proof-of-concept. Success would pave the way for applying this method to other aquatic invasive species (AIS).
Several major obstacles had to be overcome in this project to establish the foundation for genetic biocontrol of invasive carp. These included developing husbandry for year-round carp spawning in the MAISRC Containment Lab, demonstrating transgenesis of C. carpio, testing genetic reagents in a model laboratory fish needed to engineer carp, and conducting a survey to gauge public perceptions of carp genetic biocontrol. The researchers accomplished these goals within a one-year no-cost extension to the project funding.
As of late 2021, researchers at MAISRC performed several rounds of carp spawning in the MAISRC Containment Lab. Each successive attempt showed increased success: the first attempt resulted in poor spawning, the second in premature but successful spawning (an unexpected early morning spawning prevented a transgenesis attempt), and the third resulted in verified transgenic carp.
An agent-based simulation model for carp genetic biocontrol has been developed to compare several biocontrol approaches. A public opinion survey was conducted via two methods: an email to the MAISRC listserv in Fall 2018 and at the Driven to Discovery building during the 2019 MN State Fair, collecting over 1,300 responses. The survey revealed that Minnesotans are more likely to support biocontrol over chemical control, but not as much as physical methods like trapping and netting. Among biocontrol methods (predator release, pathogen release, genetic biocontrol), genetic biocontrol was the most favored. Perceptions of the relative efficacy of different methods correlated more strongly with comfort levels than perceptions of risks.
Phase II
Project manager: Michael Smanski
TImeline: 2022-2024
The overall goal of this phase is to responsibly advance technology development related to the genetic biocontrol of aquatic invasive species (AIS), specifically common carp. In the past six months, researchers have made substantial progress on many fronts. They have continued to improve carp spawning, in vitro fertilization, and transgenesis procedures. Several different transgenic carp have been created, the first of which have reached sexual maturity and have been outcrossed to wildtype carp to test their efficacy.
Progress has also been made on surrogate host technologies, which promise to accelerate research and development efforts in common carp and other AIS. In this regard, researchers have improved the husbandry, spawning, and transgenesis protocols for fathead minnows, which serve as the surrogate host. Additionally, they have demonstrated transgenic labeling of common carp primordial germ cells. Currently, researchers have begun testing the complete primordial germ cell transplantation process from common carp to fathead minnows.
Lastly, the social outreach objective of the project continues with the hosting of a second AIS Genetic Biocontrol Technology Readiness Level workshop. Although there is still some ambiguity among stakeholders and rights holders about the timing and type of social engagement and outreach in the Technology Readiness Level (TRL) classification system, researchers are preparing a manuscript to communicate the results of the 2022 and 2023 workshops.