Squirm…Squirm…
It’s 10 pm. I logged onto the computer. I could not wait to type in my username SydneyBrennerLver69 and password ILuvR-RatedWormVidz.. Slowly but surely, I clicked open the program with a blue icon – the ZEN Microscopy Software.
After focusing the plates under the objective, I switched over to digital mode. A beautiful scene of C. elegans squirming on an E.coli-seeded plate appeared on my screen. Just when I was prepared to be bored by the usual vanilla stuff (i.e., hermaphrodite doing self fertilisation and laying eggs), something caught my eye. It was a male attempting to mate with a hermaphrodite!
Contrary to humans, male C. elegans are very rare and extremely useful in many applications. Unlike human genetic males whose predominant genotype is X/Y, C. elegans sex is determined by the X to autosome ratio, with XX animals being hermaphrodites and hemizygous XO animals being males. In a hermaphrodite’s self-fertilisation event, only 0.2-0.5 percent of the offspring are male. Moreover, lab strain (N2) hermaphrodites hate mating with males. This detestation toward males is not due to selective pressure for cross progenies, post-zygotic incompatibility, or inability to mate; instead, it seems like the hermaphrodites just really hate mating with males.
But the male was mating with the hermaphrodite right in front of my eyes! He was locating the hermaphrodite’s vulva with his tail fin and opening the vulva with his spicule! How could this be happening?
It turns out that hermaphrodites increase their tendency to mate with males when they are paralysed or have defective nervous systems that make them unable to feel things. I suddenly remembered something. I removed the plate from the microscope’s stage and flipped it over. Three red letters appeared in front of my eyes: Unc.
I finally remembered what I came into the lab for. I was supposed to image my cross of Uncoordinated (Unc) worms for commissural neuron abnormalities. Instead of feeling happy that my cross was working and the worms were mating, I felt dejected. Maybe it’s the stink of E. coli. Maybe it’s the sad reality of Unc hermaphrodites mating with males. Maybe C. elegans are really, really, really gross. I don’t know. All I know is I will never use C. elegans as a model system again.
