Anyone having issues accessing it is welcome to contact me for a copy, or you can find the author's version on doi.org/10.1101/2025...

Apologies that this is paywalled - this was not our intention as University of Otago has a read and publish agreement with this publisher, however the number of APCs for open access is capped and ran out while we were being processed.

Significantly fewer tadpoles raised in vancomycin were able to regenerate tails. This suggests that gram positives- possibly via peptidoglycan activation of Tlr2 receptors - can tip the balance from wound healing to regeneration.

However, we did find in whole genome shotgun sequence that gram negative taxa were more prevalent on regenerators. To see if this had biological significance, we raised tadpoles in vancomycin, to select against gram positive colonisation.

16sRNA sequencing of 503 tadpole tail tips showed that while sibships share similar microbiomes, random forest modelling showed that there was no strong signature that could predict regeneration. Maternal haplotype, endotoxin load and bacterial load were also not predictive.

We found that genetic knockdown of Toll-like receptor 2 (Tlr2) reduces regeneration, and peptidoglycan (from bacterial cell walls) promotes it. We next looked at tadpoles from 12 sibships, linking regeneration outcome to microbiome.

At a certain stage of tadpole development, the tails of Xenopus reared in antibiotics do not regenerate when cut. We asked how the tadpole's skin microbiome and innate immunity influence this.

..such as forelimb aplasia, delayed ossification of the jaw precursor and loss of entire vascular branches on the edited side. Also, paradoxically, occasional mirror image duplication of limbs. Open access in @genetics-gsa.bsky.social G3 journal - please share and enjoy! 🧪🐸

By targeting one of these cells with GFP mRNA and Cas9 loaded with a specific sgRNA, and gene can be edited on just one side of the body. @zoologyotago.bsky.social and @otagobiochemist.bsky.social joined together to use this to show how recQ helicase variants can cause specific growth defects..

This gives you a nice internal control, with one side of the animal wild type and one side edited. We are fortunate to have fate maps for early Xenopus development, and so we know that the first cell division divides the future left from right.

Since the collective noun for frogs is an army, he can also be credited with generating the first clone army. 🐸🧪✊

Sir John is best known for his Nobel prize winning work on somatic cell nuclear transfer (cloning).

The whole mount ISH images are fantastic.

Off to a great start this afternoon with a fabulous plenary from Aaron Zorn.

#neuroskyence #EpilepsyResearchConfrerence