Arseniy Belosokhov

I just had my PhD candidacy. Grateful for a challenging and incredibly helpful examination, and for the committee’s time and thoughtful questions. A real privilege to discuss my work with such excellent scholars: @spribille.bsky.social @j-karst.bsky.social, Glen Uhrig, Daniel Stanton and Joel Dacks

Photograph of a half-eaten jam doughnut. Image by Alexander Fox | PlaNet Fox from Pixabay.

Is overeating driven by hedonism? @danasmall.bsky.social &co argue that the pleasure of eating food is not a driver of the #obesity epidemic, but rather the regular consumption of an unhealthy diet blunts sensitivity to interoceptive signals that drive food reward #neurosky 🧪
plos.io/4nTlHQc

A newly published study takes a major step toward solving one of lichen biology’s biggest questions, namely, how these symbiotic organisms produce their remarkable array of compounds known as lichen acids.

A new review paper from our lab courtesy of @jazzsynbio.bsky.social is published in Trends in Biotechnology
In this review, we look at the many opportunities for synthetic biology to be used in the research and applications of Holobionts.

The basal rosette of a thistle, showing lots of spiky leaves radiating from the centre. On the left one of them has a noticeable white and dark brown edge.

A close-up of the left-hand thistle leaf, showing a slime mould growing all around the edges.

A close-up of some of the slime mould fruiting bodies, dark brown ovals with a slight 'peacock' purple sheen, on short white stalks.

Whilst at Whitlingham C.P. today I walked past this thistle rosette and twigged that it looked slightly unusual. I stopped and had a closer look, noticing that one of the leaves has edged by the slime mould Diachea leucopodia.

*grainular

Because GenAI adoption is recent, effects may be nascent and evolving. The paper covers up to 2025 but many changes may play out over longer horizons. It will be interesting to see the continued trend to see if it's a reactive fluke or the paradigm shift.

#cortex — one of the distinct layers in a #stratified lichen thallus, covering the top surface
#reproducibility — the ability for an experiment to be readily repeated independently and yield the same results.

Please, let me know if I missed any!

#microbiota - the community of microorganisms (bacteria, yeasts, etc.) associated with a host—in this case, living naturally an invariably (and there is a very cool study on this!) within lichens

#Matrix and #Contact stages — early developmental phases in the lichenization process. Figure 2 of the original article illustrates these and later stages in more detail as the text elaborates on what is happening there

#stratified — consisting of distinct layers
#spore_discharge — many lichens actively eject their spores by shooting them up from their fruiting bodies
#lichenization — the process by which the symbiotic partners associate to form a lichen. We recognize stages leading to the full lichen structure

#in_vitro — In controlled laboratory conditions
#resynthesis — laboratory reconstruction of the lichen partnership from isolated symbionts
#photobiont — the photosynthetic partner (an alga or cyanobacterium) of a lichen symbiosis. Conversely, the lichen-forming fungus is called a #mycobiont

#thallus — the body of a lichen, built from distinct layers of symbionts, such as fungus or alga, that does not resemble the shape of any one partner in isolation
#axenic — a culture containing only one organism, free from others. You can think of it as "clean" or "pure"

As I’ve been kindly reminded by friends outside the field, not everyone wakes up thinking about fungi and algae. So allow me to fix the #accessibility of the communication piece by offering a few perhaps simplified but easy-to-grasp definitions:

I've been critically thinking about it, and came to a conclusion that cognitive recurrence and awareness of own thought process is *required* for critical thinking. It could, IF we allow it to access own process and recursively model its network patterns. #AISafety research told us not to do.

Making Fungal-Photobiont Symbioses in the Lab: Past, Present, and Future of the Elusive In Vitro Lichen The ability to synthesize lichen symbioses in vitro from pure cultures of transformable symbionts would be a game changer for experiments to identify the metabolic interplay that underpins the success...

The full text of the review article, published in Annual Review of Microbiology @annualreviews.bsky.social, is available here: doi.org/10.1146/annu...

The post illustrated with Figure 1 from the original manuscript. Original captions read: 'Scheme of lichen resynthesis from axenic component symbionts. Until now, most experiments have relied on isolated fungal and algal or cyanobacterial (photobiont) cultures to attempt resynthesis (top row). We call for experiments involving additional isolated microorganisms under a range of different environmental conditions in the search for a tractable model system that produces whole, natural-looking lichens.'

Much can be learned from this undoubtedly invaluable experimental #legacy. Rather than a verdict, we offer a #roadmap —verified purity, clear success benchmarks, reproducible methods, and tests of microbial partners. After 150 years, we finally have the tools to do it right. 8/8

So, have lichens been rebuilt from axenic cultures? The record offers almosts, maybes, and caveats. Some experiments came close; none so far has been reproducible. Instead of making claims, we present the story as it stands—open, unfinished, waiting for the next experiment. 7/8

This post is illustrated with Figure 3 of the original manuscript: "Results of major resynthesis experiments alongside natural lichens."

With non-axenic material and terrarium lichens set aside, only a handful of studies remain claiming thalli from supposedly axenic material—yet each carries caveats: unverified soil cultures, reused photos, missing cortex, bacterial traces. The closer you read, the blurrier it gets. 6/8

The image is a meme, represented by a comic parody of the Trojan Horse. A large wooden horse labelled “Lichen tissue fragment” is being pulled toward a castle gate marked “Axenic resynthesis” by person labelled “Tissue culture method.” They say, trying to convince the gatekeepers: “The best part is: it’s completely clean of algae!” Inside the horse, the hidden compartment is labelled “Resident lichen microbiota.” The cartoon humorously illustrates how supposedly sterile lichen cultures can still harbour visually undetectable microbial communities.

Then came what we affectionately call terrarium lichens: thalli ground up, filtered, sorted into “algal” and “fungal” pieces, then coaxed back together. The Tissue Culture method yielded impressive, yet unlikely #axenic structures, as resident #microbiota were never methodologically addressed. 5/8

The image shows a mock interface resembling smartphone settings with three toggle switches labeled “Axenicity,” “Complete thallus formation,” and “Reproducibility.” The switches for “Axenicity” and “Reproducibility” are turned on (blue), while “Complete thallus formation” is off (grey). Below the toggles, grey text reads: “Error: unable to activate this feature. Please, check your experimental settings.” The design humorously mimics app settings to comment on experimental challenges in achieving full lichen resynthesis.

Among the few studies that, by modern #microbiology standards, likely achieved true #axenicity, thallus formation remained limited. These cultures advanced little beyond the Contact or Matrix #lichenization stages and were not reported to reproduce the structural complexity of lichens in nature. 4/8

Defining #axenic was equally ambiguous. For much of the 20th century, spore discharge was believed to yield #sterile cultures, even as bacterial #contamination was regularly noted. Without antibiotics or molecular checks, ‘axenic’ was mostly assumed—or confirmed visually. 3/8

The image is a humorous classroom scene. A teacher stands at the front holding an open red book and smiling, asking the question. The caption at the bottom reads: “Okay, which one of you counts as the true resynthesis?”. Several students at their desks raise their hands at the same time. Instead of human heads, the students have heads replaced with stylized drawings of different lichenization stages from the Figure 2 of the original manuscript in discussion.

It turned out that ‘resynthesis’ has meant many things over time, depending on whom you asked. For some, success was a fully stratified #thallus; for others, just a fungus enclosing a few algal cells was enough to indicate lichen formation. The field never settled where ‘success’ began—or ended. 2/8

A screenshot of the "Making Fungal-Photobiont Symbioses in the Lab: Past, Present, and Future of the Elusive in Vitro Lichen" by Arseniy Belosokhov and Toby Spribille published in Annual Review of Microbiology, Volume 79, 2025. Link: https://www.annualreviews.org/content/journals/10.1146/annurev-micro-051524-031834

#Lichens form their complex thalli through a partnership involving at least a fungus and an alga. But can these living structures be rebuilt in vitro? For more than a century, people have tried. With @spribille.bsky.social we revisited 150 years of #lichen #resynthesis to ask: has anyone succeeded?

This skull is tiny! Again, illustration and photo. Could you guess the species?
The red color in the teeth that can be appreciated in the photo is their actual color 😮
#SciArt #anatomy #art #illustration #mammals

In this paper, we show that photobiont diversity increases as lichens age. Interestingly, as the thallus grows, autosporine algae become more prevalent at the expense of zoosporine algae, likely because the latter play a key role in lichen establishment. 1url.cz/@Proto