Folk, R. | bioRxiv Science

bioRxiv2022

Maternal dietary choline deficiencies during pregnancy and lactation reduce cerebral blood flow in 3-month-old female mice offspring following ischemic stroke to the sensorimotor cortex

Background and PurposeAdequate maternal dietary levels of one-carbon (1C) metabolites, such as folic acid and choline, play an important role in the closure of the neural tube in utero; however, the impact of deficiencies in 1C on offspring neurological function after birth remain undefined. Stroke is one of the leading causes of death and disability globally. The aim of our study was to determine the impact of maternal 1C nutritional deficiencies on cerebral and peripheral blood flow after ischemic stroke in adult female offspring. MethodIn this study, female mice were placed on either control (CD), folic acid (FADD), or choline (ChDD) deficient diets prior to pregnancy. Female offspring were weaned onto a CD for the duration of the study. Ischemic stroke was induced in offspring and after six weeks cerebral and peripheral blood flow velocity was measured using ultrasound imaging. ResultsOur data showed that 11.5-month-old female offspring from ChDD mothers had reduced blood flow in the posterior cerebral artery compared to controls. In peripheral blood flow velocity measurements, we report an aging effect. ConclusionsThese results emphasize the importance of maternal 1C diet in early life neuro-programming on long-term vasculature health.

neuroscience↗

bioRxiv2019

Estimating rates and patterns of diversification with incomplete sampling: A case study in the rosids

Premise of the StudyRecent advances in generating large-scale phylogenies enable broad-scale estimation of species diversification rates. These now-common approaches typically (1) are characterized by incomplete coverage without explicit sampling methodologies, and/or (2) sparse backbone representation, and usually rely on presumed phylogenetic placements to account for species without molecular data. Here we use an empirical example to examine effects of incomplete sampling on diversification estimation and provide constructive suggestions to ecologists and evolutionists based on those results.\n\nMethodsWe used a supermatrix for rosids, a large clade of angiosperms, and its well-sampled subclade Cucurbitaceae, as empirical case studies. We compared results using this large phylogeny with those based on a previously inferred, smaller supermatrix and on a synthetic tree resource with complete taxonomic coverage. Finally, we simulated random and representative taxon sampling and explored the impact of sampling on three commonly used methods, both parametric (RPANDA, BAMM) and semiparametric (DR).\n\nKey ResultsWe find the impact of sampling on diversification estimates is idiosyncratic and often strong. As compared to full empirical sampling, representative and random sampling schemes either depress or exaggerate speciation rates depending on methods and sampling schemes. No method was entirely robust to poor sampling, but BAMM was least sensitive to moderate levels of missing taxa.\n\nConclusionsWe (1) urge caution in use of summary backbone trees containing only higher-level taxa, (2) caution against uncritical modeling of missing taxa using taxonomic data for poorly sampled trees, and (3) stress the importance of explicit sampling methodologies in macroevolutionary studies.

evolutionary biology↗