SummaryThymine starvation results in a terminal cellular condition known as thymineless death (TLD), which is the basis of action for several common antibiotics and anticancer drugs. We characterized the onset and progression of TLD in Escherichia coli and found that DNA damage is the only salient property that distinguishes cells irreversibly senesced under thymine starvation from cells reversibly arrested by the nucleotide limitation. The damage is manifested as the relative loss of genetic material spreading outward from the replication origin: the extent of TLD correlates with the progression of damage. The reduced lethality in mutants deficient in the RecFOR/JQ repair pathway also correlates with the extent of damage, which explains most of the observed variance in cell killing. We propose that such spatially localized and persistent DNA damage is the consequence of transcription-dependent initiation of replication in the thymine-starved cells and may be the underlying cause of TLD.

Line 4 should read ".. . 15 to 20% of the 8,453 B. japonicum open reading frames,. .. ." Page 6753, column 1: In the first full paragraph, the third sentence should end as follows: ".. . for 8,453 predicted B. japonicum ORFs." Page 6753, column 2: The following paragraph should appear before Results. Microarray data accession number. All of the microarray data have been deposited in Gene Expression Omnibus (http://www .ncbi.nlm.nih.gov/geo/) and are available via accession number GSE9125.

Background: Neurofilament light chain (NfL) is a promising marker of disease activity/treatment response in multiple sclerosis (MS), although its predictive value for long-term clinical outcomes remains unclear. Objective: We measured NfL from a phase 3 trial in relapsing-remitting MS and investigated its association with outcomes after 8 and 15 years. Methods: NfL concentrations were measured by single molecule array assay in cerebrospinal fluid (CSF) from MS patients ( n = 235) in a 2-year randomized clinical trial (RCT) of intramuscular interferon β-1a, and in serum ( n = 164) from the extension study. Results: Year 2 CSF and Year 3 serum NfL were associated with brain parenchymal fraction (BPF) change over 8 years ( p < 0.0001, r = −0.46; p < 0.05. r = −0.36, respectively) and were predictive of reaching Expanded Disability Status Scale (EDSS) ⩾ 6.0 at Year 8 (odds ratio (OR) (upper vs lower tertile) = 3.4; 95% confidence interval (CI) = 1.2–9.9, p < 0.05; OR = 11.0, 95% CI = 2.0–114.6; p < 0.01, respectively). Serum NfL concentration (Year 4) was predictive of reaching EDSS score ⩾6.0 at 15 years (OR (upper vs lower tertile) = 4.9; 95% CI = 1.4–20.4; p < 0.05). NfL concentrations were complementary to 2-year BPF change in predicting long-term outcomes. Conclusion: Serum and CSF NfL concentrations were associated with long-term clinical outcomes in MS patients and are promising biomarkers for disease severity stratification supporting treatment decisions.