Genetic control of invasive fish species
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. Researchers will use programmable transcription activators to drive lethal embryonic overexpression of endogenous genes in hybrid embryos. Applications for this synthetic incompatibility could include population control of pest or invasive species or be utilized to prevent the spread of transgenes from genetically modified aquatic organisms to sexually reproducing wild populations.
The method involves altering the genetics of males in the invasive species before releasing them among the population, leading to sterile offspring and the eventual control of the species overall. In order to make this method usable, this study aims to develop this technology further in zebrafish, from which the system can be applied to other invasive fish species and eventually other vertebrate pests.
This control method has promise to be very species-specific, broadly applicable, and cost-effective.
The overall goal of this project is to demonstrate a novel genetic approach for controlling aquatic invasive species using invasive common carp as proof-of-concept. This project will:
- Develop state-of-the-art carp transgenesis capabilities in the laboratory so researchers have year-round access to young carp embryos
- Begin transitioning the genetic biocontrol strategy – a species-like barrier to reproduction which has already been tested in simple laboratory organisms – into carp
- Use computer modeling to predict the efficacy of the approach
- Engage the public to better understand the attitudes and opinions regarding the use of genetically engineered organisms as part of an integrated pest management plan
If this project is successful, it could lead to implementation of this technology in other aquatic invasive species, including Asian carp and zebra mussels.
As of January 2019, researchers have created protocols for creating and rearing transgenic carp in the MAISRC Containment Lab. Obtaining freshly laid eggs and fertilizing them with freshly collected sperm is a prerequisite for generating the young carp embryos needed for carp transgenesis. In Minnesota, wild carp only spawn during late spring/early summer, creating a very short window of opportunity for performing genetic engineering experiments. A serious effort towards developing new biocontrol methods in carp requires year-round access to young carp embryos, which will be achieved by maintaining several independent tanks of captive carp that have been slowly ‘trained’ to be on different annual cycles.
Researchers have also conducted a survey concerning the public perceptions surrounding genetic biocontrol of carp; learning that the public is more likely to embrace genetic biocontrol compare to alternative options, although there are knowledge gaps.
Additionally, researchers have begun a screen of genetic diversity in wild carp after gathering fin-clippings from roughly 500 wild-caught carp.
As of July 2019, researchers have successfully spawned carp during ‘off-cycle’ calendar periods. They have tested several genetic constructs in the model laboratory fish, Danio rerio., although they have not yet found a genetic design that is suitable for introduction to carp. Lastly, they organized a second iteration of our public engagement survey that was administered at the 2019 Minnesota State Fair.