Gene driven mutations

November 2017

Gene drive technology could soon become the much needed "self-sustaining, species-specific and affordable" means of eradicating horrific diseases, such as malaria, by wiping out the insect vector upon which the spread of the pathogen depends [1].

Current research is focusing on wiping out mosquitoes by giving them a gene drive with a 'nuclease' enzyme which will disrupt the function of a key mosquito gene needed for fertility in the females: by creating successive generations plagued by sterile females, the mosquito population and the disease will be decimated.

With a generation time counted in days and little tendency to fly very far during their short lives, the gene drive is predicted to be very rapidly effective in the area where the GM mosquitoes are released.

This sounds like a win-win situation (for humans), but is it that straightforward?

Organic food is a safe choice

November 2017

In the face of growing concerns that our current chemical-dependent food production systems are neither sustainable nor healthy, the European Parliament has commissioned a review of the scientific evidence of the impact of chemical-free, organic food production (see Note below).

The evidence available for review was sparse, lacking in direct human health or long-term studies, limited by reductionist data, and absent mechanistic explanations for results. In particular, the reviewers led by Swedish University of Agriculture scientists, reported that epidemiological surveys have had a very low impact on regulatory assessments despite involving real-life exposure to multiple chemicals and whole human populations.

One important, but side-lined, US population study linked pesticide levels in the mothers' body (assessed from urine levels) with impaired cognitive development in their children.

Errors in CRISPR

November 2017

We don't eat people or mice, but there's a lot to be learned from GM versions of both.

GM people aren't yet a reality, but soon could be. The first clinical trial of a GM technique to correct a faulty gene is already underway in China and another is due to start next year in America.

GM humans have become a realistic goal since the invention of the 'CRISPR/Cas9' system for making precise changes in any genome [1].

CRISPR/Cas9 has been used successfully to restore the sight of blind laboratory mice by correcting a faulty gene. The researchers didn't notice anything wrong with their GM animals. However, the technique is to be applied to humans, and there's an awareness that "every new therapy has some potential side-effects". They therefore decided to check out the possibility of "secondary mutations in (DNA) regions not targeted" by the CRISPR's RNA-homing device which seeks out the DNA sequence destined to be changed.

The dicamba tsunami

October 2017

Much in the agri-news in June were reports from US farmers whose crops had been damaged by their neighbours' use of dicamba herbicide on the latest GM crops [1].

It seems Monsanto was over-eager to sell its new decamba-tolerant soya technology so that the GM seed hit the fields before the technical details for using it had been sufficiently developed. The result has been widespread injury not only to non-dicamba-tolerant soya, but to fruit and nut crops, specialty crops, and home gardens. Damage has been progressing so fast that as soon as the statistics were compiled they were out of date. As at 15th August 2017, complaints had been made in 21 States, affecting 3.1 million acres of soyabeans alone and inciting 2,242 official investigations.

Frankenmoths RIP

October 2017

It's clear from the speed with which Bt-insecticide resistant pests are emerging that the hoped-for delaying tactic of telling farmers to plant non-Bt 'refuges' besides their Bt-generating GM crops to harbour wild-type susceptible pests just isn't working.

Biotech industry attempts to make its Bt crops easier for farmers to use by selling refuge-in-a-bag (RIB) GM seeds mixed with 5% non-GM seeds seems to have made the situation worse by diluting the level of insecticide present in the field [1].

Now, we have a new approach: refuge-in-a-pest (RIP?).

GM plants grow polio vaccines

October 2017

World-wide, polio is now a disease of the past in all but two countries. The battle has been waged with mass vaccination programmes reaching, for example, 95% of infants in Europe. Even in Pakistan and Afghanistan, polio's last stand, the annual incidence has been reducing dramatically year-on-year and is down to a few tens of cases. Indeed, conquering this virus has been one of the great success stories of modern medicine.

It's the bugs not the Bt

October 2017

Several varieties of 'Bt' insecticide are now widely generated by commercial GM crops.

These bacterial proteins are rarely directly toxic, but react with the gut lining of the target pest, creating a lesion in the gut wall. Death of the insect after 2 to 4 days, is a result of gut microbes leaking into the body.

Indeed, experiments have indicated that, for the majority of moth pest species, if their gut microbes have been destroyed by pre-treatment with antibiotics, Bt toxins are no longer able to kill them.

Putting this another way, death-by-Bt happens when the normally beneficial bugs in the healthy pests' gut move into the body where they become pathogenic.