@article {667,
	title = {Organization of the stalk system on electrocytes in mormyrid weakly electric fish Campylomormyrus compressirostris},
	journal = {Cell and Tissue Research},
	year = {2024},
	month = {Dec-20-2024},
	pages = {1-17},
	abstract = {<p><jats p="">The adult electric organ in weakly electric mormyrid fish consists of action-potential-generating electrocytes, structurally and functionally modified skeletal muscle cells. The electrocytes have a disc-shaped portion and, on one of its sides, numerous thin processes, termed stalklets. These unite to stalks leading to a single main stalk that carries the innervation site. Here, we describe the 3-dimensional layout of the stalklet/stalk system in adult <jats italic=""><em>Campylomormyrus compressirostris</em></jats> by differential interference contrast microscopy and confocal fluorescence microscopy. Using antibodies against Na<jats sup="">+</jats>/K<jats sup="">+</jats>-ATPase \&alpha;-subunit and plasma membrane Ca<jats sup="">2+</jats>-ATPase, we show that these ion pumps are differentially distributed over the stalklet/stalk system, with plasma membrane Ca<jats sup="">2+</jats>-ATPase being enriched on the stalklet membrane. Stalklets are distributed and organized in a quite uniform pattern on the posterior face of the electrocyte disc and fuse to terminal stalks. The latter then unite in a mostly dichotomic mode to stalks of increasing thickness, with the main stalk measuring about 100\&nbsp;\&micro;m in diameter. We further analyse the structural organization of stalklets and stalks, with a characteristic cytoskeletal system of bundled actin filaments in the centre and nuclei in subsurface position. These results suggest that the stalklet/stalk system is adapted in its structural layout to generate an action potential highly synchronized over the entire disc-portion of the electrocyte, accounting for the short electric organ discharge in this species. Our results suggest that actin-related proteins overexpressed in electrocytes, as shown previously by transcriptome analysis, may be involved in the organization of the unique F-actin system in stalklets and stalks.</jats></p>
},
	keywords = {Ca2+-ATPase, Confocal microscopy, electrocyte, F-actin, Plasma membrane, Sodium pump},
	issn = {0302-766X, 1432-0878},
	doi = {10.1007/s00441-024-03938-y},
	url = {https://doi.org/10.1007/s00441-024-03938-y},
	author = {Baumann, Otto and Cheng, Feng and Kirschbaum, Frank and Tiedemann, Ralph}
}
