Exon junction complex modulates the formation of the m6A epitranscriptome.

N6-methyladenosine (m6A) is one of the most abundant chemical modifications in mRNA and plays essential roles in diverse physiological and pathological processes. m6A is highly enriched near stop codons and in long internal exons of mRNA, but the mechanism leading to this specific distribution has been unclear. Recently, three papers have solved this major problem by revealing that exon junction complexes (EJCs) act as m6A suppressors and shape the formation of the m6A epitranscriptome. Here, we briefly introduce the m6A pathway, elaborate the roles of EJC on the formation of m6A modification based on these results, and describe the effect of exon-intron structure on mRNA stability via m6A, which will help us better understand the latest progress in the m6A RNA modification field.

Dynamically Rotating Magnetic Levitation to Characterize the Spatial Density Heterogeneity of Materials.

Magnetic levitation (MagLev) is a promising technology for density-based analysis and manipulation of nonmagnetic materials. One major limitation is that extant MagLev methods are based on the static balance of gravitational-magnetic forces, thereby leading to an inability to resolve interior differences in density. Here a new strategy called "dynamically rotating MagLev" is proposed, which combines centrifugal force and nonlinear magnetic force to amplify the interior differences in density. The design of the nonlinear magnetic force in tandem with centrifugal force supports the regulation of stable equilibriums, enabling different homogeneous objects to reach distinguishable equilibrium orientations. Without reducing the magnetic susceptibility, the dynamically rotating MagLev system can lead to a relatively large change in orientation angle (∆ψ > 50°) for the heterogeneous parts with small inclusions (volume fraction VF = 2.08%). The rich equilibrium states of levitating objects invoke the concept of levitation stability, which is employed, for the first time, to characterize the spatial density heterogeneity of objects. Exploiting the tunable nonlinear levitation behaviors of objects provides a new paradigm for developing operationally simple, nondestructive density heterogeneity characterization methods. Such methods have tremendous potential in applications related to sorting, orienting, and assembling objects in three dimensions.