The Melanocyte and Nerve Fiber Cross-Talk, Facilitated Also by Semaphorin-4A, Enhances UV-B-Induced Melanogenesis.

Epidermal melanocytes form synaptic-like contacts with cutaneous nerve fibers, but the functional outcome of these connections remains elusive. In this pilot study we used our fully humanized re-innervated skin organ culture model to investigate melanocyte-nerve fiber interactions in UV-B-induced melanogenesis. UV-B-irradiation significantly enhanced melanin content and tyrosinase activity in re-innervated skin compared to non-innervated controls, indicating that neuronal presence is essential for exacerbating pigmentation upon UV-B irradiation in long-term culture.

Population Genomics Reveals Local Adaptation Related to Temperature Variation in Two Stream Frog Species: Implications for Vulnerability to Climate Warming.

Identifying populations at highest risk from climate change is a critical component of conservation efforts. However, vulnerability assessments are usually applied at the species level, even though intraspecific variation in exposure, sensitivity and adaptive capacity play a crucial role in determining vulnerability. Genomic data can inform intraspecific vulnerability by identifying signatures of local adaptation that reflect population-level variation in sensitivity and adaptive capacity.

What Can Genome Sequence Data Reveal About Population Viability?

Biologists have long sought to understand the impacts of deleterious genetic variation on fitness and population viability. However, our understanding of these effects in the wild is incomplete, in part due to the rarity of sufficient genetic and demographic data needed to measure their impact. The genomics revolution is promising a potential solution by predicting the effects of deleterious genetic variants (genetic load) bioinformatically from genome sequences alone bypassing the need for costly demographic data.

New Upper Limit on the Axion-Photon Coupling with an Extended CAST Run with a Xe-Based Micromegas Detector.

Hypothetical axions provide a compelling explanation for dark matter and could be emitted from the hot solar interior. The CERN Axion Solar Telescope has been searching for solar axions via their back conversion to x-ray photons in a 9-T 10-m long magnet directed toward the Sun. We report on an extended run with the International Axion Observatory pathfinder detector, doubling the previous exposure time.