It was quite clear after couple of first years of work with frogs at subarctic that something really funny was going on – where were all the male frogs? After an unsuccessful attempt to fish for sex-specific markers with RAPDs, the sex-stuff was put to back-boiler until I started get enthusiastic e-mails from a Japanese girl – inordinately fixed on amphibians, and strong background in molecular genetics. Cim (Chikako Matsuba) eventually took a muumi-plane to Helsinki and started to play around with frogs and markers. Quite early, she stumbled on SB03-locus which got our hopes up (resulted in this BMC Genetics paper), as did the fact that the average genome size of males is less than that of females (see Hereditas paper here). But – we were still not quite sure what really was going with the sex of these frogs in Kilpisjärvi.
Now, two of the new markers developed by Cim (published here in Mol Ecol Resources) are shown to be strongly sex-linked, and together with good old SBO3, allow inference about sex-reversals in common frogs to be made. However, as the story turns out to read, the inferred sex-reversals (females becoming males) cannot explaining the sex-ratio bias in Kilpisjärvi. Something – perhaps even more interesting – is going on.
Read more about this from the Finnish media that picked up the story:
There are more of these – just browse the net! Reading the publics comments (unfortunately mostly in Finnish) on reporting, frog sex-reversals have many faceted implications. They associate with: forthcoming doomsday, strike of harbor workers, sex change of a Finnish priest, etc. Someone even thinks that we have made the story up to get rich – show us the money!
Alho J.S., C. Matsuba & J. Merilä (2010) Sex reversal and primary sex ratios in the common frog (Rana temporaria). Molecular Ecology. doi:10.1111/j.1365-294X.2010.04607.x