Please find my first, very short, foray into communication through creative writing (a mere 260 words), but I hope you enjoy it!
I was literally bouncing as I accessed the room, so many others – surely I would make a good match? The room is full each displaying their code, I move forward to see and be seen myself.
13, 12,1. No good, who’s next? 11,8,2. Still unsuitable.
The rules are strict, no numbers must match, numbers assigned at birth. 3,7,2 still wrong, will I find someone?
Time is running low, I stocked up after leaving my mother, but I cannot risk leaving such a gathering of others to restock. 6,4,3 still clashes, still wrong.
I must have a common code? Surely I should have found one? 8,12,1, another failure.
3,11,3. Really, can it be true? At last a partner!
We fuse, what a relief, and settle. An excellent site, plenty of resources, plenty of space. We, or I suppose I as we are both one now, grow and, consuming our surroundings send our filaments for more, more and more.
The time comes, food is running low, height is needed, a fruiting body it’s called. Spores are produced, released, just as I was from my mother cell. Each with a code of their own that is a combination of mine and my partner’s. Each needing, as I did, to find a match that shares none of their code.
As the food has gone and my outer filaments start to shrivel I wonder, can it really be true that others have matching so much simpler, can they really get by with just two sexes? If so, why do I Physarum polycephalum have over 500?
This was a very short story to raise awareness of the slime mould Physarum polycephalum, a protist that has over 700 sexes generated by the presence of three sex genes (matA, matB and matC). However, as described in the story, these are not all interfertile and only spores with different variants for each of the genes can fuse. One of the biggest issues that two sexes rather than many resolves is the inheritance of organelles (such as mitochondria). Physarum polycephalum overcomes this barrier with a matA hierarchy whereby the dominant variant will contribute mitochondria and the recessive will not.
I would highly recommend Olivia Judson’s book below, it is easily one of my favourite popular science books and one that is easily readable by the non-scientist too. It is where I first discovered slime mould sexes. The other two links below are papers, one looking more generally at the mating system and the other to more detail about the role of matA especially in development.
Olivia Judson (2002) Dr Tatiana’s Sex Advice to all Creation. Vintage