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Cellular barcoding methods offer the exciting possibility of ‘infinite-pseudocolor’ anatomical reconstruction—i.e., assigning each neuron its own random unique barcoded ‘pseudocolor,’ and then using these pseudocolors to trace the microanatomy of each neuron. Here we use simulations, based on densely-reconstructed electron microscopy microanatomy, with signal structure matched to real barcoding data, to quantify the feasibility of this procedure. We develop a new blind demixing approach to recover the barcodes that label each neuron, and validate this method on real data with known barcodes. We also develop a neural network which uses the recovered barcodes to reconstruct the neuronal morphology from the observed fluorescence imaging data, ‘connecting the dots’ between discontiguous barcode amplicon signals. We find that accurate recovery should be feasible, provided that the barcode signal density is sufficiently high. This study suggests the possibility of mapping the morphology and projection pattern of many individual neurons simultaneously, at high resolution and at large scale, via conventional light microscopy. 相似文献
185.
Xue Bao Martijn C Koorengevel Marian J A Groot Koerkamp Amir Homavar Amrah Weijn Stefan Crielaard Mike F Renne Joseph H Lorent Willie JC Geerts Michal A Surma Muriel Mari Frank C P Holstege Christian Klose Anton I P M de Kroon 《The EMBO journal》2021,40(20)
Phosphatidylcholine (PC) is an abundant membrane lipid component in most eukaryotes, including yeast, and has been assigned multiple functions in addition to acting as building block of the lipid bilayer. Here, by isolating S. cerevisiae suppressor mutants that exhibit robust growth in the absence of PC, we show that PC essentiality is subject to cellular evolvability in yeast. The requirement for PC is suppressed by monosomy of chromosome XV or by a point mutation in the ACC1 gene encoding acetyl‐CoA carboxylase. Although these two genetic adaptations rewire lipid biosynthesis in different ways, both decrease Acc1 activity, thereby reducing average acyl chain length. Consistently, soraphen A, a specific inhibitor of Acc1, rescues a yeast mutant with deficient PC synthesis. In the aneuploid suppressor, feedback inhibition of Acc1 through acyl‐CoA produced by fatty acid synthase (FAS) results from upregulation of lipid synthesis. The results show that budding yeast regulates acyl chain length by fine‐tuning the activities of Acc1 and FAS and indicate that PC evolved by benefitting the maintenance of membrane fluidity. 相似文献
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Sierra L. Hartney Sylvie Mazurier Teresa A. Kidarsa Maria Carolina Quecine Philippe Lemanceau Joyce E. Loper 《Biometals》2011,24(2):193-213
The soil bacterium Pseudomonas fluorescens Pf-5 produces two siderophores, a pyoverdine and enantio-pyochelin, and its proteome includes 45 TonB-dependent outer-membrane
proteins, which commonly function in uptake of siderophores and other substrates from the environment. The 45 proteins share
the conserved β-barrel and plug domains of TonB-dependent proteins but only 18 of them have an N-terminal signaling domain
characteristic of TonB-dependent transducers (TBDTs), which participate in cell-surface signaling systems. Phylogenetic analyses
of the 18 TBDTs and 27 TonB-dependent receptors (TBDRs), which lack the N-terminal signaling domain, suggest a complex evolutionary
history including horizontal transfer among different microbial lineages. Putative functions were assigned to certain TBDRs
and TBDTs in clades including well-characterized orthologs from other Pseudomonas spp. A mutant of Pf-5 with deletions in pyoverdine and enantio-pyochelin biosynthesis genes was constructed and characterized
for iron-limited growth and utilization of a spectrum of siderophores. The mutant could utilize as iron sources a large number
of pyoverdines with diverse structures as well as ferric citrate, heme, and the siderophores ferrichrome, ferrioxamine B,
enterobactin, and aerobactin. The diversity and complexity of the TBDTs and TBDRs with roles in iron uptake clearly indicate
the importance of iron in the fitness and survival of Pf-5 in the environment. 相似文献
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Fish populations in Albasini and Nandoni dams are negatively affected by extensive netting practices. This observation was made by the authors following a number of fish health assessment surveys related to aquatic pollution in the Luvuvhu River catchment. A comparison between the number and size of fish collected over a period of ten years indicated decreases in the average size and a consistent low number of fish, despite similar extensive sampling efforts. Unregulated netting is a common practice in both dams. This may become a serious problem as fish from these two dams are an important source of protein for the local communities. The purpose of this note is to report that gillnets are illegally used in the system and on the effect this could have on the fish population. The authors suggest educational and awareness initiatives to inform local communities about the importance of utilising fish in a sustainable manner to ensure the livelihood of generations to come. 相似文献
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Daniel JC Kronauer Caspar Schöning Lars B Vilhelmsen Jacobus J Boomsma 《BMC evolutionary biology》2007,7(1):56