Extended Data Fig. 1: DNA implementation of winner-take-all neural networks.
From: Scaling up molecular pattern recognition with DNA-based winner-take-all neural networks
The winner-take-all computation is broken into five subfunctions: weight multiplication, summation, pairwise annihilation, signal restoration and reporting. In the chemical reactions listed next to the five subfunctions, the species in black are needed as part of the function, the species in grey are needed to facilitate the reactions and the waste species are not shown. kf and ks are the rate constants of the pairwise-annihilation and signal-restoration reactions, respectively. In the DNA-strand-displacement implementation, weight multiplication and signal restoration are both catalytic reactions. The grey circle with an arrow indicates the direction of the catalytic cycle. Representative, but not all possible, states are shown for the pairwise-annihilation reaction. Zigzag lines indicate short (5 or 7 nucleotide) toehold domains and straight lines indicate long (15 or 20 nucleotide) branch-migration domains in DNA strands, with arrowheads marking their 3′ ends. Each domain is labelled with a name, and asterisks in the names indicate sequence complementarity. Black-filled and white-filled arrowheads indicate the forwards and backwards directions of a reaction step, respectively. All DNA sequences are listed in Supplementary Table 1.
