The revised version of our paper on the desmosomal #connectome of the #Platynereis larva is now out
https://elifesciences.org/articles/71231
by Sanja Jasek et al.
#volumeEM #rstat
Sanja skeletonised all the 853 muscle cells in the larva and annotated their desmosomes and the partner cells and extracellular structures that the desmosomes attach to. This resulted in a single network of over 2,000 cells and extracellular structures (basal lamina, chitin endoskeleton etc) that we call the desmosomal #connectome. In synaptic connectomes the links are formed by #synapses, in a desmosomal connectome the links are desmosomes.
We analysed the network in many different ways and found that its structure is quite different from the synaptic #connectome and random networks. One of the interesting findings was that the #aciculae - chitin rods that form an #endoskeleton in the segmental #appendages - are highly connected hubs in the #network and a large number of #muscles is involved in moving them.
The #endoskeleton formed by the #aciculae and supported by many muscles is quite unique to polychaete annelids and represents the only example outside the #tetrapods of animals with a trunk appendages rigidified by an endoskeleton. Aciculae evolved in stem errant #annelids in the Early #Ordovician indicating the deep ancestry of these structures, predating tetrapod limbs.
We also mapped #motoneuron synapses to the desmosomal connectome to infer the extent of tissue influenced by motoneurons. We suggest that such cellular-level maps based on #volumeEM data and the integrative analysis of synaptic and adherent force networks will be important to elucidate body mechanics and the nervous control of movement.
In this paper we generated most of the figures entirely in R for open science and reproducibility. All code is shared here:
https://github.com/JekelyLab/Jasek_et_al
The figures and analyses can be regenerated by the code that will query our public #CATMAID database where all EM data, tracings and annotations are shared:
https://catmaid.jekelylab.ex.ac.uk (project id: 11)
#openscience #rstat