Reposted by Álvaro Fernández
Peter Hegemann and Georg Nagel – awarded the 2026 medicine prize – discovered a remarkable protein, channelrhodopsin, in a single-celled alga.
Hegemann wondered how Chlamydomonas, a single-celled alga, is able to swim towards a light source.
![Fig. 1 (shortened, full legend in paper): Local wounding induces systemic increase in extracellular ATP (eATP) level. (A, C) The experimental design for measuring changes of eATP levels and cytosolic free calcium concentration ([Ca2+]cyt) in response to local wounding at a single leaf (A) or the main root (C). L1–L5 indicate the different leaves. (B, D) Left panel, representative images of changes of eATP luminescence signals of wild type (WT) seedlings that were subjected to local wounding at a single leaf (B) or the main root (D). Right panel, quantification of the eATP luminescence signal in leaf 1 (wounded leaf) and leaf 5 (which was chosen as a representative systemic leaf) (B), or in the wounded main root and rosette leaves (leaf 1-leaf 5) (D), to evaluate the systemic change of the eATP levels in response to the local wounding. Un-wounded seedlings were used as the controls. Each value represents the mean ±SE (n≥19 in B; n≥13 in D).](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:ggz22gcwkakll7efac23g33s/bafkreidb6bkxn4sdm5odvqoz4ssylzvplcuqmgt3exw7oij64c4stxyyau)
