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Simulation is a key tool in population genetics for both methods development and empirical research, but producing simulations that recapitulate the main features of genomic datasets remains a major obstacle. Today, more realistic simulations are possible thanks to large increases in the quantity and quality of available genetic data, and the sophistication of inference and simulation software. However, implementing these simulations still requires substantial time and specialized knowledge. These challenges are especially pronounced for simulating genomes for species that are not well-studied, since it is not always clear what information is required to produce simulations with a level of realism sufficient to confidently answer a given question. The community-developed framework stdpopsim seeks to lower this barrier by facilitating the simulation of complex population genetic models using up-to-date information. The initial version of stdpopsim focused on establishing this framework using six well-characterized model species (Adrion et al., 2020). Here, we report on major improvements made in the new release of stdpopsim (version 0.2), which includes a significant expansion of the species catalog and substantial additions to simulation capabilities. Features added to improve the realism of the simulated genomes include non-crossover recombination and provision of species-specific genomic annotations. Through community-driven efforts, we expanded the number of species in the catalog more than threefold and broadened coverage across the tree of life. During the process of expanding the catalog, we have identified common sticking points and developed the best practices for setting up genome-scale simulations. We describe the input data required for generating a realistic simulation, suggest good practices for obtaining the relevant information from the literature, and discuss common pitfalls and major considerations. These improvements to stdpopsim aim to further promote the use of realistic whole-genome population genetic simulations, especially in non-model organisms, making them available, transparent, and accessible to everyone.

Stochastic simulation is a key tool in population genetics, since the models involved are often analytically intractable and simulation is usually the only way of obtaining ground-truth data to evaluate inferences. Because of this, a large number of specialized simulation programs have been developed, each filling a particular niche, but with largely overlapping functionality and a substantial duplication of effort. Here, we introduce msprime version 1.0, which efficiently implements ancestry and mutation simulations based on the succinct tree sequence data structure and the tskit library. We summarize msprime's many features, and show that its performance is excellent, often many times faster and more memory efficient than specialized alternatives. These high-performance features have been thoroughly tested and validated, and built using a collaborative, open source development model, which reduces duplication of effort and promotes software quality via community engagement.

Plants growing on seabird-nesting islands are uniquely adapted to deal with guano-derived soils high in N and P. Such ornithocoprophilous plants found in isolated, oceanic settings provide useful models for ecological and evolutionary investigations. The current study explored the plants found on Mount Desert Rock (MDR), a small seabird-nesting, oceanic island 44 km south of Mount Desert Island (MDI), Hancock County, Maine, U.S.A. Twenty-seven species of vascular plants from ten families were recorded. Analyses of guano-derived soils from the rhizosphere of the three most abundant species from bird-nesting sites of MDR showed significantly higher (P < 0.05) NO3-, available P, extractable Cd, Cu, Pb, and Zn, and significantly lower Mn compared to soils from the rhizosphere of conspecifics on non-bird nesting coastal bluffs from nearby MDI. Bio-available Pb was several-fold higher in guano soils than for background levels for Maine. Leaf tissue elemental analyses from conspecifics on and off guano soils showed significant differences with respect to N, Ca, K, Mg, Fe, Mn, Zn, and Pb, although trends were not always consistent. Two-way ANOVA indicated a significant interaction between species and substrate for Ca, Mg, Zn, and Pb tissue accumulation, showing that for these four elements there is substantial differentiation among species found on and off of guano soil. A compilation of species lists from other important seabird-nesting islands in the region suggested an ornithocoprophilous flora for northeastern North America consisting of 168 species from 39 families, with Asteraceae (29 taxa; 17.3%), Poaceae (25 taxa; 14.9%), Polygonaceae (10 taxa; 5.95%), Caryophyllaceae (9 taxa; 5.4%), and Rosaceae (9 taxa; 5.4%) as the most species-rich families. The taxa were predominantly hermaphroditic (69%) and perennial (66%) species, native (60%) to eastern North America. [ABSTRACT FROM AUTHOR]

The electronic or molecular mechanisms that initiate photobiomodulation (PBM) in cells are not yet fully understood. The porcine complex III (C-III) of the electron transport chain was characterized with transient absorption spectroscopy (TAS). We then applied our recently developed continuous wave laser coupled TAS procedure (CW-TAS) to investigate the effect of red light irradiances on the heme dynamics of C-III in its c 1 reduced state. The time constants were found to be 3.3 ± 0.3 ps for vibrational cooling of the oxidized state and 4.9 ± 0.4 ps for rebinding of the photodissociated axial ligand of the c 1 reduced state. The analysis of the CW-TAS procedure yielded no significant changes in the C-III heme dynamics. We rule out the possibility of 635 nm CW light at 4.7 mW/cm 2 inducing a PBM effect on the heme dynamic of C-III, specifically with the photodissociation of its axial ligand., Competing Interests: The authors declare no conflicts of interest., (© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.)

The physiological switch in expression of the embryonic, fetal, and adult β-like globin genes has garnered enormous attention from investigators interested in transcriptional mechanisms and the molecular basis of hemoglobinopathies. These efforts have led to the discovery of cell type-specific transcription factors, unprecedented mechanisms of transcriptional coregulator function, genome biology principles, unique contributions of nuclear organization to transcription and cell function, and promising therapeutic targets. Given the vast literature accrued on this topic, this article will focus on the master regulator of erythroid cell development and function GATA-1, its associated proteins, and its frontline role in controlling hemoglobin synthesis. GATA-1 is a crucial regulator of genes encoding hemoglobin subunits and heme biosynthetic enzymes. GATA-1-dependent mechanisms constitute an essential regulatory core that nucleates additional mechanisms to achieve the physiological control of hemoglobin synthesis.