As a consequence of the accumulation of insertion events over evolutionary time, mobile elements now comprise nearly half of the human genome. The Alu, L1, and SVA mobile element families are still ...duplicating, generating variation between individual genomes. Mobile element insertions (MEI) have been identified as causes for genetic diseases, including hemophilia, neurofibromatosis, and various cancers. Here we present a comprehensive map of 7,380 MEI polymorphisms from the 1000 Genomes Project whole-genome sequencing data of 185 samples in three major populations detected with two detection methods. This catalog enables us to systematically study mutation rates, population segregation, genomic distribution, and functional properties of MEI polymorphisms and to compare MEI to SNP variation from the same individuals. Population allele frequencies of MEI and SNPs are described, broadly, by the same neutral ancestral processes despite vastly different mutation mechanisms and rates, except in coding regions where MEI are virtually absent, presumably due to strong negative selection. A direct comparison of MEI and SNP diversity levels suggests a differential mobile element insertion rate among populations.
Antibody-mediated responses play a critical role in vaccine-mediated immunity. However, for reasons that are poorly understood, these responses are highly variable between individuals. Using a mouse ...model, we report that antibiotic-driven intestinal dysbiosis, specifically in early life, leads to significantly impaired antibody responses to five different adjuvanted and live vaccines. Restoration of the commensal microbiota following antibiotic exposure rescues these impaired responses. In contrast, antibiotic-treated adult mice do not exhibit impaired antibody responses to vaccination. Interestingly, in contrast to impaired antibody responses, immunized mice exposed to early-life antibiotics display significantly enhanced T cell cytokine recall responses upon ex vivo restimulation with the vaccine antigen. Our results demonstrate that, in mice, antibiotic-driven dysregulation of the gut microbiota in early life can modulate immune responses to vaccines that are routinely administered to infants worldwide.
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•Antibiotic exposure in infant mice impairs antibody responses to five vaccines•Restoring the commensal microbiota rescues impaired antibody responses•Antibiotic-treated adult mice exhibit normal antibody responses to vaccination•CD4+ T cells from antibiotic-exposed infant mice have enhanced cytokine recall responses
Using an infant mouse model, Lynn, Tumes, and colleagues report that antibiotic-driven dysbiosis in early life leads to impaired antibody responses to five vaccines that are administered to human infants worldwide. In contrast, ex vivo cytokine recall responses are elevated. Restoring the commensal microbiota is sufficient to rescue impaired antibody responses.
Sediment cores from Florida Bay, Everglades National Park were examined to determine ecosystem response to relative sea-level rise (RSLR) over the Holocene. High-resolution multiproxy analysis from ...four sites show freshwater wetlands transitioned to mangrove environments 4-3.6 ka, followed by estuarine environments 3.4-2.8 ka, during a period of enhanced climate variability. We calculate a RSLR rate of 0.67 ± 0.1 mm yr
between ~4.2-2.8 ka, 4-6 times lower than current rates. Despite low RSLR rates, the rapid mangrove to estuarine transgression was facilitated by a period of prolonged droughts and frequent storms. These findings suggest that with higher and accelerating RSLR today, enhanced climate variability could further hasten the loss of mangrove-lined coastlines, compounded by the reductions in natural flow to the coast caused by water management. Climate variability is nonlinear, and when superimposed on increases in RSLR, can complicate estimated trajectories of coastal inundation for resource management and urban planning.
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