🎉 Big news! 🎉

We will be moving to @bristolbiosci.bsky.social @bristoluni.bsky.social in 2026!!

We're so excited to be joining such a dynamic and thriving department, university, and city - thank you to everyone who has already been so welcoming!

📢 But that's not all - come and join us! 👇

Fresh(ish) from the week at BESSY II @helmholtz.de looking at the changes associated with eye loss in spiders! Not pictured: our valiant night shifters, @mikebok.bsky.social, Karla Lopez Reyes, and Constance Coubris 💪🏼🌃

Armed with data from the major clades, we can finally start to identify phylogenetic patterns of RDG expression!

As ever, new questions spring up as we attempt to answer old ones, but hopefully this is one more step to understanding how spider eyes have achieved such diversity of form and function!

Many of the retinal determination genes are present in duplicate, thanks to an ancient whole-genome duplication in arachnopulmonates. In the case of Six3, it appear that one copy is expressed at the centre of the secondary eyes, and the other surrounds it. Why? We don't know! But watch this space...

We also detected early gene expression in the principal eye primordia of Segestria senoculata, which *lack* AMEs and probably lost them 100s Ma...

Fun fact! The very small eye pair in salticids, historically called the posterior median eyes, in fact appears to be homologous to the posterior *lateral* eyes of other spiders!
The salticid PMEs are dead, long live the salticid PMEs!
(Cue lots of annoying nomenclature confusion, sorry)

For example, extreme eye sizes are already established by stage 10-11 in salticids and lycosids, and the early division of the secondary eye primordium seems to contribute to their eventual positions on the cephalothorax, particularly the posterior lateral eyes.
3/n

Although the retinal determination gene (RDG) repertoires are pretty conserved across the order, their spatial and temporal expression patterns provide clues about how important features such as eye size, function, and location might be determined, and how these have evolved over time
2/n

Thanks to the teams at the Soleil Anatomix and DISCO beamlines for hosting us and @sigwartae.bsky.social @oceanspecies.bsky.social this week! We learned lots of new tricks and are looking forward to working through the data together soon! There are always fun new ways to look at old chitons 💛