This study is interesting. It relates to the company and what happened to the mosquitoes when they tested it in Brazil and Malaysia.
TLDR: Mosquito population became suppressed at first but rebounded to pre-release levels and some carried the genetics of the GM mosquitoes (3% survival rate and can reproduce), unknown implications of hybrid vigor.
"However, it is clear from the data in Garziera et al.6 that the effectiveness of the release program began to break down after about 18 months, i.e., the population which had been greatly suppressed rebounded to nearly pre-release levels. This has been speculated to have been due to mating discrimination against OX513A males, a phenomenon known to occur in sterile male release programs
The release strain, OX513A, was derived from a laboratory strain originally from Cuba, then outcrossed to a Mexican population7. The three populations forming the tri-hybrid population now in Jacobina (Cuba/Mexico/Brazil) are genetically quite distinct (Extended Data Fig. E2), very likely resulting in a more robust population than the pre-release population due to hybrid vigor.
These results demonstrate the importance of having in place a genetic monitoring program during releases of transgenic organisms to detect un-anticipated consequences."
The Editors are issuing an Editorial Expression of Concern for this Article.
Shortly after publication of this Article in September 2019, the Editors were alerted to concerns regarding the interpretation of the data and some of the conclusions. Specific concerns include:
- the title does not make it clear that the authors only examined genomes of specimens that lacked the transgenes and sampled during the release period;
- the Abstract and Introduction use language which is not justified given the evidence present in the peer reviewed literature and the data presented in this Article. No sampling for this study was conducted more than a few weeks after the release program, and as such there is no evidence in the Article to establish whether the non-transgenic, introgressed sequences from the released strain remained in the population over time. Furthermore, previous work from some of the authors (Reference 6 in the Article) showed that over time, the transgene is lost from the population, but the Article does not disclose this information;
- in the Discussion, the authors claim that because of the distinct genetic backgrounds of different mosquito populations (two used to create OX513A mosquitoes, and one local population), the existing population in Jakobina is more robust than the original wild population due to hybrid vigour. There are no data in the Article to support this point; furthermore, data included in the Article indicate that a number of hybrid individuals rapidly declined post-release;
- the conclusion of the Article highlighting “the importance of having in place a genetic monitoring program during such releases” could be misunderstood to mean that such program was not in place. The Mosquito release program in Jakobina is monitored by the Brazilian regulator, the National Technical Commission of Biosafety (CTNBio).
When contacted about these issues, some of the authors indicated that they had not approved the final version that was submitted for publication.
The Editors received a response to the concerns from the corresponding author, and sought further advice from expert peer reviewers regarding both the issues raised and the response received. The reviewers confirmed that the scientific concerns are valid and should be addressed.
I wonder what's going on there, at the bottom it lists the authors of the original study and if they agree or disagree with the expression of concern. It's almost split between Yale and the Brazilians, with one exception, whith the Brazilians agreeing and the Yale people disagreeing.
Yes, there are dissenting authors. But I think people misinterpreted what I said. I highlighted that implications of a more robust hybrid is unknown.
I think the biggest misnomer of this is that the media keeps referring to the mosquitoes as 'sterile' while the developers of the OX513A strain had reported that adults were observed among progeny of transgenic females and males at rates of 4.2 and 2.6% respectively and repeatedly acknowledge incomplete penetrance, so if there is surprise surrounding the existence of F1 adults and the possibility of matings.
An updated press release by Oxitec stated that "A small proportion (3-5%) of the OX513A mosquitoes can survive" and that "local mosquito populations in Jacobina slowly rebounded after the releases of OX513A mosquitoes stopped at the project’s conclusion". The questionable part is that the author added a statement that stated "very likely resulting in a more robust population than the pre-release population due to hybrid vigor". This is the questionable part because evidence for a more "robust" mosquito population did not exist. So what happened after? There has not been one post release study on changes in a postrelease population. There has not been one peer reviewed study nor a study that wasn't a conflict of interest / funding bias.
Evans et al. observed that after releases of millions– repeat millions- of transgenic males into the city of Jacobina, Brazil that the frequency of exotic single-nucleotide polymorphisms (SNPs) from the release strain genome increased so that 10-60% of the individuals contained detectable release-strain SNPs. This demonstrated that release strain genotypes were being introduced into the population. Small, but detectable levels of the OX513A genomes were also observed in nearby populations, presumably due to migration.
The authors did not describe the spread or persistence of the transgene itself, only of the genome of the release strain.
The salient question is, does harm result?
One possible avenue of harm that might result would be if the release strain conferred an ability to transmit a pathogen at higher rates than the target population. In this case, the study determined that as far as this was examined, there was no evidence to indicate this (a result puzzlingly presented in the Evans et al. Discussion section). Another possibility, greater insecticide resistance, had been dismissed previously by studies conducted at LSTM.
The Evans et al. paper includes another possible harm. They speculate in the Discussion section that hybrid vigor would result in a ‘more robust population than the pre-release population’. Ok. That’s commonly observed in many biological systems and is not a controversial statement though less certainty might be prudent.
The developers acknowledged survival to adulthood, so some degree of transgenic strain introgression was inevitable. Evans et al. have served the field well to describe an instance of this and their speculation regarding changes in the population should stimulate follow-up observations.
If, as Evans et al. suggest, a more robust population has resulted, this is of concern.
Further research into whether the Jacobina population is indeed more robust and now mates assortatively seems not only feasible but extremely enlightening. One good experiment stops endless arguments and the authors are well-suited to pursue this.These populations offer an ideal opportunity to test some of the generalizations that are stated.
We simply do not know. We also do not know what reports were given to the government agencies that were involved in this project, were they peer reviewed literature? Vector capacity of the population is a concern and comparisons should be made. Introducing invasive species have come with numerous ill unwanted effects to our ecosystems; Kudzu, Pythons (hmm florida...), Asian Carp (looking at you again florida), etc... Florida just does not have a good track record.
With the FONSI, Oxitec planned field testing in Key Haven, FL, in collaboration with the Florida Keys Mosquito Control District. However, the Florida Keys Environmental Coalition and others petitioned the Florida Commissioner of Agriculture and Consumer Services to halt any field testing of the OX513A mosquitoes in the state. The Florida Keys Mosquito Control Board did not approve the trial release, instead putting it on a November 2016 ballot as a non-binding referendum. The Key Haven neighborhood (where the test site was planned) rejected the proposed release. 65% voted against the plan, while 57% of the county said yes. This was a straw poll, which is non binding.
With local opposition to the planned release, Oxitec withdrew its application for an EUP. Oxitec researchers subsequently developed a second-generation GE mosquito. EPA granted an EUP to Oxitec in May 2020 to test the efficacy of this second-generation GE mosquito expressing the tTAV-OX5034 protein. EPA regulates the GE mosquito as a biopesticide under the Federal Insecticide, Fungicide, and Rodenticide Act (7 U.S.C §136c).
Second generation mosquitoes have said to only produce male offsprings and can be distributed as eggs. In June, the Center for Food Safety (CFS) filed a notice of intent to sue unless EPA revokes Oxitec’s EUP to test the second-generation mosquito in Monroe County, FL, and Harris County, TX. CFS’s notice charges that the EUP is a violation of Section 7 of the Endangered Species Act.
"Phil Goodman is the chairman of the board of the Florida Keys Mosquito Control District. He’s said the 2nd Generation technology overcomes many hurdles its predecessor didn’t including, potentially, the cost."
“That’s something that does have to be paid close attention to,” says entomologist Zach Adelman of Texas A&M University in College Station. When Oxitec stops its releases, mosquito numbers will rebound, and it is not clear whether or how the genes from the release strain would influence the recovered population, including how mosquitos seek out hosts, mate, or lay eggs, for example. Of key concern, he says, is how good Oxitec’s strain is at transmitting viruses compared with wild mosquitoes—its so-called vector competence. So far, studies of such changes in a postrelease population are missing, Adelman says.
Simon Warner, Oxitec’s chief scientific officer in Abingdon, U.K., says there’s no reason to think their lab strain—descendants of mosquitoes collected in Cuba, crossed with a Mexican strain—would be any more dangerous than another strain of A. aegypti. “Vector competence is not a question that we’ve been asked by the [FDA] regulators,” he says. “We haven’t studied it, because we don’t think it’s a concern.”
At the end of the day, we dont know what the implications are, especially with the second generation. This isn't a battle of muh G.M.O. bad. G.M.O.s are absolutely necessary in today's world.
But before doing something that can have consequences, there should be more studies, peer reviewed and not with funding/sponsorship bias. The government and companies should be more transparent. At the end of the day, the discussion was just a song and dance, A final decision was made by the Florida Keys Mosquito Control District Board, regardless of who voted.
This is the perfect outcome for the company profits. Now they can sell a bunch of GM mosquitos each 18 months. A bug for the consumers, a feature for the developers.
Not really; if the new, hybrid population of mosquitoes have learned to discriminate against the gene-carrying males, then new releases won't work -- unless it's with another gene, maybe, but that would probably take more than 18 months to make.
This study is interesting. It relates to the company and what happened to the mosquitoes when they tested it in Brazil and Malaysia.
TLDR: Mosquito population became suppressed at first but rebounded to pre-release levels and some carried the genetics of the GM mosquitoes (3% survival rate and can reproduce), unknown implications of hybrid vigor.
"However, it is clear from the data in Garziera et al.6 that the effectiveness of the release program began to break down after about 18 months, i.e., the population which had been greatly suppressed rebounded to nearly pre-release levels. This has been speculated to have been due to mating discrimination against OX513A males, a phenomenon known to occur in sterile male release programs
The release strain, OX513A, was derived from a laboratory strain originally from Cuba, then outcrossed to a Mexican population7. The three populations forming the tri-hybrid population now in Jacobina (Cuba/Mexico/Brazil) are genetically quite distinct (Extended Data Fig. E2), very likely resulting in a more robust population than the pre-release population due to hybrid vigor.
These results demonstrate the importance of having in place a genetic monitoring program during releases of transgenic organisms to detect un-anticipated consequences."