The rate and spectrum of new mutations in mice inferred by long-read sequencing.

All forms of genetic variation originate from new mutations, making it crucial to understand their rates and mechanisms. Here, we use long-read PacBio sequencing to investigate de novo mutations that accumulated in 12 inbred mouse lines derived from three commonly used inbred strains (C3H, C57BL/6, and FVB) maintained for 8-15 generations in a mutation accumulation (MA) experiment. We built chromosome-level genome assemblies based on the MA line founders' genomes, and then employed a combination of read and assembly-based methods to call the complete spectrum of new mutations.

Chain stretching in brushes favors sequence recognition for nucleobase-functionalized flexible precise oligomers.

Six different flexible stereocontrolled oligo(triazole-urethane)s substituted by precise sequences of nucleobases or analogs are synthesized. Molecular dynamics simulations indicate that the flexibility of the backbone leads to unspecific complexation of pairs of oligomers, irrespective of the complementarity of their sequences. This is ascribed to the existence of other interactions between pairs of oligomers, as well as to the spatial blurring of the sequence order encoded in the chemical structure of the chain due to its flexibility.

Variation in the Spectrum of New Mutations among Inbred Strains of Mice.

The mouse serves as a mammalian model for understanding the nature of variation from new mutations, a question that has both evolutionary and medical significance. Previous studies suggest that the rate of single-nucleotide mutations (SNMs) in mice is ∼50% of that in humans. However, information largely comes from studies involving the C57BL/6 strain, and there is little information from other mouse strains.

Absorption Correction for 3D Elemental Distributions of Dental Composite Materials Using Laboratory Confocal Micro-X-ray Fluorescence Spectroscopy.

Confocal micro-X-ray fluorescence (micro-XRF) spectroscopy facilitates three-dimensional (3D) elemental imaging of heterogeneous samples in the micrometer range. Laboratory setups using X-ray tube excitation render the method accessible for diverse research fields but interpretation of results and quantification remain challenging. The attenuation of X-rays in composites depends on the photon energy as well as on the composition and density of the material.