Joshua Christie


A photo of Joshua Christie

I started my PhD in the Behaviour and Genetics of Social Insects Lab in 2013, which is more than a little ironic given that I study neither behavior nor sociality nor even insects. Instead, I am broadly interested in the evolution of mitochondrial inheritance. Mitochondria contain small genomes that code for a subset of the proteins necessary to generate energy for the cell. Both males and females contribute nuclear genes to the offspring during sex, but only the mother transmits mitochondrial genes. Even in species that have morphologically indistinguishable gametes instead of sexes, a single partner almost always transmits the mitochondria. I am interested in how (and why) the uniparental inheritance of mitochondria evolved.

To this end, I utilise both mathematic modelling and laboratory experiments. I use the acellular slime mould Physarum polycephalum for my empirical research. The slime mould has a solid claim to being the most charismatic non-animal around. It can find the shortest path through a maze, construct networks on par with human engineers, and use its goo as memory. Not bad for an organism that is effectively a pulsating bag of slime. Mitochondrial inheritance is predominantly uniparental in the slime mould, but specific crosses inherit biparentally leading to cells that contain different mitochondrial types. I am interested in whether there are costs associated with the maintenance of different mitochondrial types in a single cell.

slime mold

Photo courtesy of Malcolm Ricketts