Category Archives: horizontal gene transfer

Horizontal gene transfer from Zygo to pea aphid

Pea AphidAnother result from the analysis of the recently published genome of the pea aphid, Acyrthosiphon pisum. Nancy Moran and Tyler Jarvik present a study of the origin of the carotenoid production gene in pea aphid. Animals typically cannot make carotenoids so they sought to discover how this is possible. They find that it is derived from a horizontal gene transfer event of a fungal gene into the aphid lineage. This gene is responsible for the red-green color polymorphism in the aphid. It appears the gene is derived from a ‘zygomycete’ or relative in the early branching lineage of the fungi. One gene, a carotenoid desaturase, is encoded in a 30kb genomic region that is missing in green aphids but present in the red morphs. The region is apparently maintained in the population by frequency dependent selection since each color has an advantage or disadvantage for evading detection by predators in different environments.

The reports of eukaryotic HGT event from fungi to animals is quite rare so this finding is surprising in that sense, but the authors argue that the important ecological role of carotenoids suggest we might see even more examples if we look harder.

Moran, N., & Jarvik, T. (2010). Lateral Transfer of Genes from Fungi Underlies Carotenoid Production in Aphids Science, 328 (5978), 624-627 DOI: 10.1126/science.1187113

Fungal Genetics 2007 details

I’m including a recapping as many of the talks as I remember. There were 6 concurrent sessions each afternoon so you have to miss a lot of talks. The conference was bursting at the seams as it was- at least 140 people had to be turned away beyond the 750 who attended.

If there was any theme in the conference it was “Hey we are all using these genome sequences we’ve been talking about getting”. I only found the overview talks that solely describe the genome solely a little dry as compared to those more focused on particular questions. I guess my genome palate is becoming refined.

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