Iñaki Ruiz-Trillo

1/3 Remember our #Magnificent8? 8 mysterious lineages related to animals, known only from environmental DNA. 🧬 We suspected they were just the tip of the iceberg, hiding many more "unknown unknowns". Our new preprint suggests we were right. 🧵 👉https://bit.ly/3TUYowB #protistsOnSky

2/3 We identified 31 uncharacterized lineages across Holozoa & opisthokonts. Some are deep evolutionary branches outside any known group of animal relatives. Others are hidden within groups we thought we knew. Many are widespread, yet we know nothing about them! @ibe-barcelona.bsky.social

Did cell types exist before animals? What if the first cell types evolved before the first animals? We'll use #ichthyosporeans, tiny microbes with the potential to reshape how we think about animal origins. #ProtistsOnSKy @ibe-barcelona.bsky.social @prbb.org @csic.es 🧵

Most people have never heard of #apusomonads. Yet these tiny protists occupy an important position in the eukaryotic tree of life. And we know so little about them! We're looking for a Master's student to help uncover their hidden diversity. #ProtistsOnSky 🧵 @ibe-barcelona.bsky.social @prbb.org

1/7 Really interesting new preprint by Mannsåker et al. on the evolution of TRP channels in #choanoflagellates. But what caught my attention wasn't simply the diversity of these sensory receptors. It was something more general about how biological innovation may arise. 🧵 #protistsOnSky

6/7 Perhaps this reflects a broader evolutionary principle. The ancestor of animals may already have possessed a rich molecular toolkit. Different holozoan lineages then expanded different parts of that toolkit independently. Evolution was already experimenting long before animals appeared.

1/7 Really interesting new preprint by Mannsåker et al. on the evolution of TRP channels in #choanoflagellates. But what caught my attention wasn't simply the diversity of these sensory receptors. It was something more general about how biological innovation may arise. 🧵 #protistsOnSky

4/7 Perhaps the evolutionary route toward sensory complexity began with new ways of organizing existing ones inside single cells. Subcellular patterning before cellular specialization. This fits well with the "beta-testing" pre-metazoan phase we recently proposed: doi.org/10.1038/s443...

1/7 Really interesting new preprint by Mannsåker et al. on the evolution of TRP channels in #choanoflagellates. But what caught my attention wasn't simply the diversity of these sensory receptors. It was something more general about how biological innovation may arise. 🧵 #protistsOnSky

2/7 Animals rely on specialized sensory cells. Their unicellular ancestors probably did not. This study shows that closest unicellular relatives of animals already possessed a remarkably diverse repertoire of TRP channels and that these proteins occupy distinct subcellular territories.

1/2 Embryonic organizers, a group of cells that can coordinate the behaviour of many others. have been viewed as one of the true innovations of animals. Fascinating new paper @kremnyovs.bsky.social @hejnol.bsky.social @genikhovich.bsky.social et al. now reports organizer activity in #ctenophores.

1/3 Cell adhesion is considered one of the foundations of animal #multicellularity. Yet whether #ctenophores possess a functional cadherin–catenin complex has remained surprisingly controversial. A new study revisits that question. 🧵 @ctenophoresrock.bsky.social

2/3 The authors show that ctenophores possess a functional #cadherin–catenin interaction network. The cadherin–catenin complex is one of the central systems underlying animal cell adhesion and tissue organization.

1/9 For years, debates about microbial biogeography have sometimes been framed as a choice. Either microorganisms are everywhere. Or geography matters. But what if that is a false choice? @ibe-barcelona.bsky.social @icreacommunity.bsky.social @prbb.org @csic.es #protistsOnSKy

8/9 And they raise an intriguing possibility. If microorganisms can expand across ocean basins while still retaining traces of their history... How much reflects natural processes? How much bears the signature of human-mediated dispersal?

1/9 For years, debates about microbial biogeography have sometimes been framed as a choice. Either microorganisms are everywhere. Or geography matters. But what if that is a false choice? @ibe-barcelona.bsky.social @icreacommunity.bsky.social @prbb.org @csic.es #protistsOnSKy

6/9 This matters because population genetics contains historical information. Present-day distributions tell us where organisms are. Genetic structure helps reveal how they got there.

1/9 For years, debates about microbial biogeography have sometimes been framed as a choice. Either microorganisms are everywhere. Or geography matters. But what if that is a false choice? @ibe-barcelona.bsky.social @icreacommunity.bsky.social @prbb.org @csic.es #protistsOnSKy

4/9 Yet they are not genetically homogeneous. The same haplotypes can occur across distant oceans. At the same time, populations frequently retain detectable genetic structure. This combination is difficult to reconcile with a simple view of unrestricted cosmopolitanism.

1/9 For years, debates about microbial biogeography have sometimes been framed as a choice. Either microorganisms are everywhere. Or geography matters. But what if that is a false choice? @ibe-barcelona.bsky.social @icreacommunity.bsky.social @prbb.org @csic.es #protistsOnSKy

2/9 Our study, lead by Rubén, compares #protists, animals and plants within a single population-genetic framework. We ask how their genetic diversity is distributed across the world's oceans. Link: www.science.org/doi/10.1126/...