An extinct north American porcupine with a South American tail.

New World porcupines (Erethizontinae) originated in South America and dispersed into North America as part of the Great American Biotic Interchange (GABI) 3-4 million years ago. Extant prehensile-tailed porcupines (Coendou) today live in tropical forests of Central and South America. In contrast, North American porcupines (Erethizon dorsatum) are thought to be ecologically adapted to higher-latitude temperate forests, with a larger body, shorter tail, and diet that includes bark.

Ice Age megafauna rock art in the Colombian Amazon?

Megafauna paintings have accompanied the earliest archaeological contexts across the continents, revealing a fundamental inter-relationship between early humans and megafauna during the global human expansion as unfamiliar landscapes were humanized and identities built into new territories. However, the identification of extinct megafauna from rock art is controversial. Here, we examine potential megafauna depictions in the rock art of Serranía de la Lindosa, Colombian Amazon, that includes a giant sloth, a gomphothere, a camelid, horses and three-toed ungulates with trunks.

Mandipropamid as a chemical inducer of proximity for in vivo applications.

Direct control of protein interactions by chemically induced protein proximity holds great potential for both cell and synthetic biology as well as therapeutic applications. Low toxicity, orthogonality and excellent cell permeability are important criteria for chemical inducers of proximity (CIPs), in particular for in vivo applications. Here, we present the use of the agrochemical mandipropamid (Mandi) as a highly efficient CIP in cell culture systems and living organisms.

Bio-orthogonal Red and Far-Red Fluorogenic Probes for Wash-Free Live-Cell and Super-resolution Microscopy.

Small-molecule fluorophores enable the observation of biomolecules in their native context with fluorescence microscopy. Specific labeling via bio-orthogonal tetrazine chemistry combines minimal label size with rapid labeling kinetics. At the same time, fluorogenic tetrazine-dye conjugates exhibit efficient quenching of dyes prior to target binding.

Light-induced protein proximity by activation of gibberellic acid derivatives in living cells.

Light controlled tools are highly attractive for the modulation and manipulation of biological processes. As an external trigger light can be applied with high temporal and special control to various samples. In the recent years a number of optochemical and -genetic tools have been developed to translate the input of light into molecular changes that result in specific biological responses.

A Bioorthogonal Click Chemistry Toolbox for Targeted Synthesis of Branched and Well-Defined Protein-Protein Conjugates.

Bioorthogonal chemistry holds great potential to generate difficult-to-access protein-protein conjugate architectures. Current applications are hampered by challenging protein expression systems, slow conjugation chemistry, use of undesirable catalysts, or often do not result in quantitative product formation. Here we present a highly efficient technology for protein functionalization with commonly used bioorthogonal motifs for Diels-Alder cycloaddition with inverse electron demand (DA ).

Enzymatic and Site-Specific Ligation of Minimal-Size Tetrazines and Triazines to Proteins for Bioconjugation and Live-Cell Imaging.

Diels-Alder reactions with inverse electron demand (DA) have emerged as an indispensable tool for bioorthogonal labeling and the manipulation of biomolecules. In this context, reactions between tetrazines and strained dienophiles have received attention because of high reaction rates. Current methods for the DA-mediated functionalization of proteins suffer from slow reactivity, impaired stability, isomerization, or elimination of the incorporated strained dienophiles.

Siderophore inspired tetra- and octadentate antenna ligands for luminescent Eu(III) and Tb(III) complexes.

Following the success of the siderophore-inspired 1,2-hydroxypyridonate (HOPO) and 2-hydroxisophthalamide (IAM) chromophores in Eu(III) and Tb(III) luminescence, we designed three new ligands bearing both chromophores. Syntheses of the octadentate ligands 3,4,3-LI-IAM-1,2-HOPO and 3,4,3-LI-1,2-HOPO-IAM, where the chromophores are attached to different positions in the (LI=linear) spermine backbone, are reported in addition to a tetradentate ligand based on 1,5-diaminopentane. The Gd(III) complexes were prepared and revealed localized triplet states typical for the IAM and HOPO chromophores.