Author Archives: heathobrien

About heathobrien

I am a genome scientist based in Bristol, England. I am currently studying the genetic basis of neuropsychiatric disorders, but I have also done research on iridescent plants, plant pathogens and lichens. I have continued my work on lichen-associated algae and cyanobacteria for my blog

PhotobiontDiversity has moved!

I’ve recently completed migration of this blog from to This move will allow the creation of a number of new features, the first of which is described in this post. Unfortunately, I’ve not been able to migrate subscriptions to the … Continue reading

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Another perspective on diversity of symbiotic cyanobacteria: 16S

Up to this point, I have been focusing on the rbcX locus for all investigations of cyanobacterial photobionts because it is probably the most extensively sampled locus and it is more variable than 16S rDNA. However, it is limited because … Continue reading

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Symbiotic Nostoc Revisited

In the three months or so that I’ve been working on this blog there has been some evolution in the methods I’m using. I though it would be worthwhile to revisit the first group I looked at to see if … Continue reading

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Green Algal Photobionts: Trentepohlia

While most work has focused on coccoid green algae and/or cyanobacteria, a largely overlooked lineage of lichen photobionts is the Trentepoliales, a group of filamentous, carotenoid producing green algae. Trentepohlian algae are associated with one fifth of lichen species world … Continue reading

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Green Algal Photobionts: Coccomyxa

After a few weeks of for a vacation, it’s time to get back to green algal photobionts. In addition to Trebouxia and Asterochloris, there are several other genera of Trebouxiophycean algae that act as photobionts for various groups of lichens. … Continue reading

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Gunnera symbionts do not cluster with lichen photobionts

I have been kicking around the idea of setting up an online catalog of lichen photobionts for years before I started doing this. The main impetus to finally start was this paper: Fernández-Martínez, M., de los Ríos, A., Sancho, L., & Pérez-Ortega, … Continue reading

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Green Algal Photobionts: Asterochloris.

In this post I will be taking a look at the diversity of the junior partner to Trebouxia: Asterochloris. Originally described by Elisabeth Tschermak-Woess in 1980, Asterochloris was subsequently merged with Trebouxia before being split out again on the basis of sequence data … Continue reading

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