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Linker of nucleoskeleton and cytoskeleton complexes consist of outer nuclear membrane KASH proteins, interacting in the nuclear envelope lumen with inner nuclear membrane SUN proteins and connecting nucleus and cytoskeleton. The paralogous Arabidopsis KASH proteins SINE1 and SINE2 function during stomatal dynamics induced by light-dark transitions and ABA, which requires F-actin reorganization. SINE2 influences actin depolymerization and SINE1 actin repolymerization. The actin-related protein 2/3 (ARP2/3) complex, an actin nucleator, and the plant actin bundling and stabilizing factor SCAB1 are involved in stomatal aperture control. Here, we have tested the genetic interaction of SINE1 and SINE2 with SCAB1 and the ARP2/3 complex. We show that SINE1 and the ARP2/3 complex function in the same pathway during ABA-induced stomatal closure, while SINE2 and the ARP2/3 complex play opposing roles. The actin repolymerization defect observed in sine1-1 is partially rescued in scab1-2 sine1-1, while SINE2 is epistatic to SCAB1. In addition, SINE1 and ARP2/3 act synergistically in lateral root development. Absence of SINE2 renders trichome development independent of the ARP2/3 complex. Together, these data reveal complex and differential interactions of the two KASH proteins with the actin-remodeling apparatus and add evidence to the proposed differential role of SINE1 and SINE2 in actin dynamics. 

High rates of dispersal can breakdown coadapted gene complexes. However, concentrated genomic architecture (i.e., genomic islands of divergence) can suppress recombination to allow evolution of local adaptations despite high gene flow. Pacific lamprey (Entosphenus tridentatus) is a highly dispersive anadromous fish. Observed trait diversity and evidence for genetic basis of traits suggests it may be locally adapted. We addressed whether concentrated genomic architecture could influence local adaptation for Pacific lamprey. Using two new whole genome assemblies and genotypes from 7,716 single nucleotide polymorphism (SNP) loci in 518 individuals from across the species range, we identified four genomic islands of divergence (on chromosomes 01, 02, 04, and 22). We determined robust phenotype-by-genotype relationships by testing multiple traits across geographic sites. These trait associations probably explain genomic divergence across the species’ range. We genotyped a subset of 302 broadly distributed SNPs in 2,145 individuals for association testing for adult body size, sexual maturity, migration distance and timing, adult swimming ability, and larval growth. Body size traits were strongly associated with SNPs on chromosomes 02 and 04. Moderate associations also implicated SNPs on chromosome 01 as being associated with variation in female maturity. Finally, we used candidate SNPs to extrapolate a heterogeneous spatiotemporal distribution of these predicted phenotypes based on independent data sets of larval and adult collections. These maturity and body size results guide future elucidation of factors driving regional optimization of these traits for fitness. Pacific lamprey is culturally important and imperiled. This research addresses biological uncertainties that challenge restoration efforts. 

Abstract Mechanisms behind the phenomenon of Arctic amplification are widely discussed. To contribute to this debate, the (AC) 3 project was established in 2016 ( www.ac3-tr.de/ ). It comprises modeling and data analysis efforts as well as observational elements. The project has assembled a wealth of ground-based, airborne, shipborne, and satellite data of physical, chemical, and meteorological properties of the Arctic atmosphere, cryosphere, and upper ocean that are available for the Arctic climate research community. Short-term changes and indications of long-term trends in Arctic climate parameters have been detected using existing and new data. For example, a distinct atmospheric moistening, an increase of regional storm activities, an amplified winter warming in the Svalbard and North Pole regions, and a decrease of sea ice thickness in the Fram Strait and of snow depth on sea ice have been identified. A positive trend of tropospheric bromine monoxide (BrO) column densities during polar spring was verified. Local marine/biogenic sources for cloud condensation nuclei and ice nucleating particles were found. Atmospheric–ocean and radiative transfer models were advanced by applying new parameterizations of surface albedo, cloud droplet activation, convective plumes and related processes over leads, and turbulent transfer coefficients for stable surface layers. Four modes of the surface radiative energy budget were explored and reproduced by simulations. To advance the future synthesis of the results, cross-cutting activities are being developed aiming to answer key questions in four focus areas: lapse rate feedback, surface processes, Arctic mixed-phase clouds, and airmass transport and transformation.