Dr Mike McGrew, gene weaver

Image

With the famed Midwestern ethos of hard graft and humility in his bones, Minnesota native Mike took a while to acknowledge that he had earned his stripes in the field of avian genetics and shake off the impostor syndrome that at one time threatened to thwart his impressive career.

Hard work has always come naturally to Mike, who by the age of 16 was the night manager at a taco shack in his hometown of St Paul. All of Mike’s friends had jobs too, and when they graduated from high school they went straight into the workforce, but Mike’s parents had other ideas for him. Born in Depression-era America, Mike’s mother and father felt strongly that education was a way of providing security for oneself in hard times and were themselves both university graduates. Mike’s aptitude for maths and science was apparent from a very young age, and so as he approached the end of his high school days his parents insisted that he go into higher education.

Mike went to the University of Minnesota, his father’s alma mater, where he enrolled to study aerospace engineering because he thought it would lead to good job prospects. But he found the course and the cohort a little drab compared to the colourful life he lived outside of the lecture theatre. Looking for inspiration he switched to physics, then chemistry, all the while waiting tables to support himself and maintain ties with his friends outside of university life. After several attempts to find his niche, Mike found his passion subject in biology, but it was the people rather than the discipline that first caught his eye. In comparison to his rather sensible aerospace classmates, the biology set appeared to be so much more diverse and exciting. “Maybe that’s what drew me to biology,” he says. “All the wacky people were involved in it.” Mike loved his biology course, and he graduated with a minor in biochemistry.

Keen to get working after graduation, Mike was surprised to hear that he would need to pursue another degree before he’d be considered a serious hire prospect. He was accepted on to a molecular biology PhD program at Boston University under the tutelage of muscle cell biology powerhouse Nadia Rosenthal, a move that would both set the course for Mike’s career and sow the seeds of impostor syndrome.

“Nadia was then a rising star and people wanted to be around her and work for her,” Mike says. “It was a great time but it scared me a little because there was no way that I could become the same kind of leader that she was.”

During his PhD Mike studied gene expression using transgenic mice – mice that had had a small DNA sequence from another species introduced at the embryonic stage - and he became fascinated by the early embryo. The work inspired him to enrol for the world-famous Embryology Course at the University of Chicago’s Marine Biological Laboratory (MBL). Established in 1893, the intensive six-week summer course is renowned for shaping the field, with six former students and eight faculty members becoming Nobel Laureates. The course exposed Mike to a wide variety of genetic and experimental embryonic systems including chicks, zebrafish, sea urchins, mice and molluscs. “It really lit a fire in me to study the early embryonic stages” he says, and a chance encounter he’d had with another scientist some months before would soon allow him to realise this dream.

At a conference Nadia Rosenthal introduced Mike to another rising star in the field of genetics, Olivier Pourquié, who was then a Group Leader at the French National Centre for Scientific Research (CNRS). Mike noted that it was Bastille Day and that, as a French national, Pourquié should be celebrating, which resulted in the two scientists sitting poolside until the small hours drinking too much bourbon. Months later, once Mike had completed the MBL course and gained his PhD, he made cautious contact with Pourquié to ask for a job. Pourquié remembered the hangover Mike had caused him, but he still agreed to take the young graduate on.

An EMBO fellowship enabled Mike to take up his post-doctoral position at the Marseille Developmental Biology Institute (IBDM), where Pourquié had recently relocated his lab. Mike spent a happy four years working under Pourquié’s mentorship, during which time the group made the breakthrough discovery of the segmentation clock, the basic rhythmic process of how an embryo times when and where to make body segments. But when Pourquié announced that he was moving his lab over to Kansas, Minnesota, Mike couldn’t follow him. “I said ‘I cannot go back to the Midwest’. It’s ridiculous, I shouldn’t have mattered where I moved, but I just thought it would be rather boring in Kansas, plus it was time to do something else.”

More pressingly, Mike was approaching burnout. After several years of working for some of the brightest lights in the field, and despite all the skills and experience he had accrued over that time, Mike felt he wasn’t good enough to follow in the footsteps of Rosenthal and Pourquié. “It's hard to work for these megastars,” he says. “We had a great time but it scared me, it made me think ‘I'm just this tiny person, there's no way I can be as organised or as good as them, I couldn’t be a Group Leader.’”

He didn’t feel confident in taking the same path as his mentors, so he started looking for other jobs. In 2001 a postdoctoral research scientist position at the Roslin Institute caught his eye, but when he came to Edinburgh to interview it became clear he wasn’t a good fit. Fortunately, developmental biologist Professor Helen Sang was also looking to hire a postdoc at the time, to help her develop her world-leading techniques for making transgenic chicken. Mike had the necessary embryology know-how for modifying chickens, plus years of experience making transgenic mice. Sang offered him the position and Mike has been at the Roslin Institute ever since.

Since joining the Institute Mike’s career has gone from strength to strength. After his postdoc fellowship ended, he became a Career Track Fellow, and in 2012 he became a Group Leader after all. What happened between Marseille and Edinburgh to change his mind? “After I came to Roslin I gradually realised that I had such expertise in embryology, and a unique skill set,” He says. “I finally recognised that I was as good as the people around me.”

Having found his niche once more, Mike became, like his mentors, the person who others want to be around and work with. As well as being an in-demand speaker on the international conference circuit, in 2019 he was nominated for Teacher of the Year by his students, and his innovative research has captured the attention of industry experts. 

For several years now Mike has been working in collaboration with the Gates Foundation-funded Centre for Tropical Livestock Genetics, and Cobb-Vantress, the world’s oldest poultry-breeding company, to boost the welfare, productivity and biodiversity of poultry and help safeguard them against changing environmental conditions through gene-editing technology. The team have developed sterile surrogate chickens that are capable of laying eggs from any rare breed. By implanting reproductive stem cells (which make the sperm and eggs of birds) of a donor chicken breed into sterile male and female chicken eggs and then mating the resulting birds together, Mike and his team have successfully produced chicks of the donor breed. This astonishing development not only means that beneficial genes can be transferred from one breed into another via gene editing of embryos - and in a single generation - but rare chicken breeds can be safeguarded from obsolescence by storing their frozen reproductive cells in bio-banks. In 2021 the Roslin team and Cobb were presented with the Powerful Partnership Award at the Scottish Knowledge Exchange Awards in recognition of the strides they have made together towards greater disease resistance, food security and animal welfare.

Mike’s poultry research continues, but with climate change on his mind he’s increasingly focused on making biobanking feasible for other bird species, so that the technology can help preserve endangered wildlife. 

“We’re going to lose so many bird species to global warming,” He says. “And we need something that will help. This biobanking and surrogate host work would be useful as part of a captive breeding program for ecologists or conservation biologists who are already working in this area, and I think we could give them some technology to help them accomplish their goals.”

Applying his innovative gene-editing techniques to wild bird species is a complex, long-term project, but luckily for the songbirds he’s so fond of Mike has never been one to shy away from hard work.